SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 10-Q

QUARTERLY REPORT UNDER SECTION 13 OR 15(d) OF
THE SECURITIES EXCHANGE ACT OF 1934

For the quarter ended   March 31, 2006           Commission file number 1-640
------------------                                -------

NL INDUSTRIES, INC.                         
--------------------------------------------------------------------------------
(Exact name of Registrant as specified in its charter)

New Jersey                                           13-5267260    
-------------------------------                           ---------------------
(State or other jurisdiction of                               (IRS Employer
incorporation or organization)                            Identification No.)

5430 LBJ Freeway, Suite 1700, Dallas, Texas  75240-2697           
--------------------------------------------------------------------------------
(Address of principal executive offices)     (Zip Code)

Registrant's telephone number, including area code:             (972) 233-1700
----------------

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months and (2) has been subject to such filing requirements for
the past 90 days. Yes X  No
---   ---

Indicate by check mark whether the Registrant is a large  accelerated  filer, an
accelerated  filer or a  non-accelerated  filer (as defined in Rule 12b-2 of the
Securities  Exchange Act of 1934).  
Large accelerated filer    Accelerated filer X  Non-accelerated filer
---                  ---                      ---

Indicate by check mark whether the  Registrant is a shell company (as defined in
Rule 12b-2 of the Act). Yes     No X
---    ---

Number of shares of the Registrant's common stock outstanding on April 28, 2006:
48,563,034.

NL INDUSTRIES, INC. AND SUBSIDIARIES

INDEX

Page
number

Part I.      FINANCIAL INFORMATION

Item 1.    Financial Statements

Consolidated Balance Sheets -
December 31, 2005; March 31, 2006
(Unaudited)                                                   1

Consolidated Statements of Income -
Three months ended March 31, 2005 and 2006
(Unaudited)                                                   3

Consolidated Statements of Comprehensive Income (Loss) -
Three months ended March 31, 2005 and 2006
(Unaudited)                                                   4

Consolidated Statement of Stockholders' Equity -
Three months ended March 31, 2006
(Unaudited)                                                   5

Consolidated Statements of Cash Flows -
Three months ended March 31, 2005 and 2006
(Unaudited)                                                   6

Notes to Consolidated Financial Statements (Unaudited)         8

Item 2.    Management's Discussion and Analysis of Financial
Condition and Results of Operations                          20

Item 3.    Quantitative and Qualitative Disclosure About
Market Risk                                                  33

Item 4.    Controls and Procedures                                       33

Part II.     OTHER INFORMATION

Item 1.    Legal Proceedings                                             34

Item 1A.   Risk Factors                                                  35

Item 6.    Exhibits                                                      35

NL INDUSTRIES, INC. AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS

(In thousands)

ASSETS                                        December 31,         March 31,
2005                2006
------------        -----------
(Unaudited)

Current assets:

Cash and cash equivalents                                  $   76,912          $   68,088
Restricted cash and cash equivalents                            4,327               3,835
Restricted marketable debt securities                           9,265               9,405
Accounts and other receivables, net                            23,392              25,507
Refundable income taxes                                           424                 851
Receivable from affiliates                                      3,291               2,551
Inventories, net                                               22,538              22,005
Prepaid expenses                                                1,718               1,165
Deferred income taxes                                           7,295               7,202
----------          ----------

Total current assets                                      149,162             140,609
----------          ----------

Other assets:
Marketable equity securities                                   87,120              83,352
Investment in Kronos Worldwide, Inc.                          146,774             149,125
Deferred income taxes                                               4                -
Goodwill                                                       27,240              27,418
Other, net                                                      5,499               5,859
----------          ----------

Total other assets                                        266,637             265,754
----------          ----------

Property and equipment:
Land                                                            8,511               9,202
Buildings                                                      28,001              28,483
Equipment                                                     110,917             113,041
Construction in progress                                        2,015               3,525
----------          ----------
149,444             154,251
Less accumulated depreciation and amortization                 80,540              85,242
----------          ----------

Net property and equipment                                 68,904              69,009
----------          ----------

$  484,703          $  475,372
==========          ==========

NL INDUSTRIES, INC. AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS (CONTINUED)

(In thousands)

LIABILITIES AND STOCKHOLDERS' EQUITY                     December 31,         March 31,
2005                2006
------------        -----------
(Unaudited)

Current liabilities:

Current maturities of long-term debt                       $      171          $       52
Accounts payable                                               11,079               9,817
Accrued liabilities                                            29,859              27,757
Accrued environmental costs                                    13,302              12,028
Payable to affiliates                                             982               1,138
Income taxes                                                      599                 360
----------          ----------

Total current liabilities                                  55,992              51,152
----------          ----------

Noncurrent liabilities:
Long-term debt                                                  1,425                  41
Accrued pension costs                                             942                 468
Accrued postretirement benefits costs                          10,141               9,644
Accrued environmental costs                                    41,645              40,867
Deferred income taxes                                         107,000             107,073
Other                                                           2,246               2,186
----------          ----------

Total noncurrent liabilities                              163,399             160,279
----------          ----------

Minority interest                                                45,630              45,578
----------          ----------

Stockholders' equity:
Common stock                                                    6,070               6,070
Additional paid-in capital                                    363,233             363,242
Retained earnings                                                -                    423
Accumulated other comprehensive income (loss):
Marketable securities                                        34,084              31,586
Currency translation                                       (141,018)           (140,271)
Pension liabilities                                         (42,687)            (42,687)
----------          ----------

Total stockholders' equity                                219,682             218,363
----------          ----------

$  484,703          $  475,372
==========          ==========

Commitments and contingencies (Notes 10 and 12)

See accompanying notes to consolidated financial statements.

NL INDUSTRIES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF INCOME

Three months ended March 31, 2005 and 2006

(In thousands, except per share data)

(Unaudited)

2005               2006
----               ----

Net sales                                                       $   46,843         $   47,029
Cost of sales                                                       36,560             35,401
----------         ----------

Gross margin                                                    10,283             11,628

Selling, general and administrative expense                          6,122              6,718
Other operating income (expense):
Currency transaction losses, net                                     (54)               (41)
Disposition of property and equipment                                 (4)               (73)
Insurance recoveries                                                   -              2,236
Other income                                                         265                 13
Corporate expense                                                 (5,837)            (4,096)
----------         ----------

Income (loss) from operations                                   (1,469)             2,949

Equity in earnings of Kronos Worldwide, Inc.                         7,790              5,381
Other income (expense):
Trade interest income                                                 21                 75
Interest and dividend income from affiliates                         619                471
Other interest income                                                866                868
Securities transactions, net                                      14,578                 57
Interest expense                                                     (80)               (61)
----------         ----------

Income from continuing operations before 
income taxes and minority interest                            22,325              9,740

Provision for income taxes                                           6,778              2,496

Minority interest in after-tax earnings                                731                751
----------         ----------

Income from continuing operations                               14,816              6,493

Discontinued operations                                               (326)              -
----------         ----------

Net income                                                  $   14,490         $    6,493
==========         ==========

Basic and diluted net income per share                          $      .30         $      .13
==========         ==========
Weighted-average shares used in the calculation 
of net income per share:
Basic                                                             48,490             48,563
Dilutive impact of stock options                                      71                 24
----------         ----------

Diluted                                                           48,561             48,587
==========         ==========

See accompanying notes to consolidated financial statements.

NL INDUSTRIES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)

Three months ended March 31, 2005 and 2006

(In thousands)

(Unaudited)

2005               2006
----               ----

Net income                                                      $   14,490         $    6,493
----------         ----------

Other comprehensive income (loss), net of tax:

Marketable securities adjustment                               10,805             (2,498)

Currency translation adjustment                                 1,308                747
----------         ----------

Total other comprehensive income (loss)                       12,113             (1,751)
----------         ----------

Comprehensive income                                  $   26,603         $    4,742
==========         ==========

See accompanying notes to consolidated financial statements.

NL INDUSTRIES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY

Three months ended March 31, 2006

(In thousands)

(Unaudited)

Accumulated other
comprehensive income (loss)
Additional              -------------------------------------------
Common    paid-in      Retained    Marketable      Currency       Pension
stock     capital      earnings    securities    translation    liabilities      Total
----------------------------------------------------------------------------------------

Balance at December 31, 2005                $6,070   $363,233   $   -       $  34,084        $(141,018)   $ (42,687)       $219,682

Net income                                    -          -         6,493         -                -            -              6,493

Issuance of common stock                      -             9       -            -                -            -                  9

Dividends                                     -          -        (6,070)        -                -            -             (6,070)

Other comprehensive income (loss) , net       -          -          -          (2,498)             747         -             (1,751)
------   --------   --------    ---------        ---------    ---------        --------

Balance at March 31, 2006                   $6,070   $363,242   $    423    $  31,586        $(140,271)   $ (42,687)       $218,363
======   ========   ========    =========        =========    =========        ========

See accompanying notes to consolidated financial statements.

NL INDUSTRIES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS

Three months ended March 31, 2005 and 2006

(In thousands)

(Unaudited)

2005               2006
----               ----

Cash flows from operating activities:

Net income                                                   $   14,490         $    6,493
Depreciation and amortization                                     2,807              2,790
Deferred income taxes:
Continuing operations                                           3,012              1,011
Discontinued operations                                          (187)              -
Minority interest:
Continuing operations                                             731                751
Discontinued operations                                          (151)              -
Equity in earnings of Kronos Worldwide, Inc.                     (7,790)            (5,381)
Dividends from Kronos Worldwide, Inc.                             4,456              4,379
Securities transactions, net                                    (14,578)               (57)
Benefit plan expense less than cash funding:
Defined benefit pension plans                                    (217)              (662)
Other postretirement benefit plans                               (289)              (498)
Other, net                                                          875                340
Change in assets and liabilities:
Accounts and other receivables                                 (4,246)            (2,115)
Inventories                                                       (46)               343
Prepaid expenses                                                  216                550
Accrued environmental costs                                      (975)            (2,052)
Accounts payable and accrued liabilities                       (2,930)            (3,409)
Income taxes                                                    3,509               (511)
Accounts with affiliates                                          589                806
Other, net                                                     (3,162)              (766)
----------         ----------

Net cash provided by (used in) 
operating activities                                     (3,886)             2,012
----------         ----------

Cash flows from investing activities:
Capital expenditures                                             (5,253)            (2,593)
Change in restricted cash equivalents and 
marketable debt securities, net                                  1,046                550
Proceeds from disposal of:
Business unit                                                  18,094               -
Kronos common stock                                            19,047               -
Marketable securities                                           4,173              3,746
Purchase of:
CompX common stock                                                  -               (404)
Marketable securities                                          (3,161)            (3,967)
Cash of disposed business unit                                   (4,006)              -
Other, net                                                            6                  7
----------         ----------

Net cash provided by (used in) 
investing activities                                      29,946             (2,661)
----------         ----------

NL INDUSTRIES, INC. AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS (CONTINUED)

Three months ended March 31, 2005 and 2006

(In thousands)

(Unaudited)

2005               2006
----               ----

Cash flows from financing activities:
Indebtedness:

Principal payments                                         $      (10)        $   (1,476)
Deferred financing costs paid                                     (28)              (105)
Cash dividends paid                                               -                 (6,070)
Distributions to minority interest                                 (602)              (578)
Proceeds from issuance of common stock:
NL common stock                                                 2,413                  9
CompX common stock                                                191               -
----------         ----------

Net cash provided by (used in) 
financing activities                                       1,964             (8,220)
----------         ----------

Cash and cash equivalents - net change from:
Operating, investing and financing activities                    28,024             (8,869)
Currency translation                                                217                 45
Cash and cash equivalents at beginning of period                   99,185             76,912
----------         ----------

Cash and cash equivalents at end of period                     $  127,426         $   68,088
==========         ==========

Supplemental disclosures - cash paid for:
Interest, net of amounts capitalized                        $      55         $       45
Income taxes, net                                               3,050                945

Noncash investing activity - note receivable
received upon disposal of business unit                $   4,179         $     -

See accompanying notes to consolidated financial statements.

NL INDUSTRIES, INC. AND SUBSIDIARIES

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

Note 1 -       Organization and basis of presentation:

NL Industries,  Inc. (NYSE: NL) is a subsidiary of Valhi, Inc. (NYSE: VHI).
At March 31, 2006, (i) Valhi held  approximately 83% of NL's outstanding  common
stock and (ii) Contran  Corporation and its subsidiaries held  approximately 92%
of Valhi's outstanding common stock.  Substantially all of Contran's outstanding
voting stock is held by trusts  established for the benefit of certain  children
and grandchildren of Harold C. Simmons, of which Mr. Simmons is sole trustee, or
is held by Mr.  Simmons  or persons or other  entities  related to Mr.  Simmons.
Consequently, Mr. Simmons may be deemed to control each of such companies.

The Company's  ownership of CompX (NYSE:  CIX) is held principally by CompX
Group,  Inc.  The Company owns 82.4% of CompX  Group,  Inc. and Titanium  Metals
Corporation  ("TIMET")  (NYSE:  TIE), an affiliate of Valhi,  owns the remaining
17.6% of CompX  Group.  CompX  Group's  sole asset  consists  of shares of CompX
common stock representing  approximately 83% of the total number of CompX shares
outstanding.  At March 31,  2006,  NL owned  70% of CompX  common  stock,  which
represents  NL's ownership  interest in CompX Group  multiplied by CompX Group's
ownership  interest in CompX and an additional 2% of CompX owned directly by NL.
At March 31, 2006, NL also directly owned 36% of Kronos  Worldwide,  Inc. (NYSE:
KRO) CompX,  Kronos and TIMET each file periodic reports with the Securities and
Exchange  Commission ("SEC") pursuant to the Securities Exchange Act of 1934, as
amended.

The  consolidated  balance  sheet at March 31, 2006,  and the  consolidated
statements of income, comprehensive income (loss), stockholders' equity and cash
flows for the interim  periods ended March 31, 2005 and 2006, have been prepared
by  the  Company,  without  audit,  in  accordance  with  accounting  principles
generally  accepted in the United States of America ("GAAP").  In the opinion of
management,  all adjustments,  consisting only of normal recurring  adjustments,
necessary  to state  fairly  the  consolidated  financial  position,  results of
operations and cash flows have been made.

The  results of  operations  for the interim  periods  are not  necessarily
indicative  of the  operating  results for a full year or of future  operations.
Certain  information  normally  included  in  financial  statements  prepared in
accordance  with GAAP has been condensed or omitted.  The  consolidated  balance
sheet data as of  December  31,  2005 was  derived  from the  Company's  audited
consolidated  financial  statements  at that  date,  but  does not  include  all
disclosures  required by GAAP,  as  permitted  by  regulations  of the SEC.  The
accompanying  consolidated  financial  statements  should be read in conjunction
with the Company's  Annual  Report on Form 10-K for the year ended  December 31,
2005 (the "2005 Annual Report").

Note 2 - Accounts and other receivables, net:

December 31,           March 31,
2005                 2006
------------          ----------
(In thousands)

Trade receivables                                              $ 20,921            $ 23,134
Other receivables                                                 2,783               2,713
Allowance for doubtful accounts                                    (312)               (340)
--------            --------

$ 23,392            $ 25,507
========            ========

Note 3 - Inventories, net:

December 31,           March 31,
2005                 2006
------------          ----------
(In thousands)

Raw materials                                                  $  7,098            $  6,423
In process products                                               9,899               9,876
Finished products                                                 5,541               5,706
--------            --------

$ 22,538            $ 22,005
========            ========

Note 4 - Marketable equity securities:

At December 31, 2005 and March 31, 2006,  the Company  owned  approximately
4.7 million  shares of Valhi common  stock with a quoted  market price of $17.70
per share (December 31, 2005 quoted market price - $18.50 per share).

Note 5 - Investment in Kronos:

At March 31, 2006,  the Company  held 17.5 million  shares of Kronos with a
quoted  market price of $30.36 per share,  or an aggregate  market value of $532
million.

At March  31,  2006,  Kronos  reported  total  assets of $1.3  billion  and
stockholders'  equity of $416.5 million.  Kronos' total assets at March 31, 2006
include current assets of $554.3  million,  net property and equipment of $416.9
million,  deferred income taxes of $213.1  million,  and an investment in a TiO2
manufacturing  joint venture of $118.1  million.  Kronos' total  liabilities  at
March 31, 2006 include current liabilities of $198.3 million,  long-term debt of
$493.3 million,  accrued  postretirement  benefits and pension costs aggregating
$147.9 million and deferred income taxes of $54.0 million.

During the three months ended March 31, 2006,  Kronos reported net sales of
$304.3  million,  income from  operations of $34.4 million and net income of $15
million (2005: $291.9 million, $46.4 million and $21.4 million, respectively).

Note 6 - Other noncurrent assets, net:

December 31,           March 31,
2005                 2006
------------          ----------
(In thousands)

Definite-lived customer list intangible asset, net             $  1,115            $  1,022
Patents and other intangible assets, net                          2,317               2,221
Other                                                             2,067               2,616
--------            --------

$  5,499            $  5,859
========            ========

Note 7 - Accrued liabilities:

December 31,           March 31,
2005                 2006
------------          ----------
(In thousands)

Employee benefits                                              $ 10,933            $  9,196
Professional fees                                                 5,269               5,113
Other                                                            13,657              13,448
--------            --------

$ 29,859            $ 27,757
========            ========

Note 8 - Other noncurrent liabilities:

December 31,           March 31,
2005                 2006
------------          ----------
(In thousands)

Insurance                                                      $  2,224            $  1,998
Other                                                                22                 188
--------            --------

$  2,246            $  2,186
========            ========

Note 9 - Minority interest:

December 31,           March 31,
2005                 2006
------------          ----------
(In thousands)

Minority interest in net assets -
CompX International Inc.                                     $ 45,630            $ 45,578
========            ========

Three months ended
March 31,
----------------------
2005              2006
----              ----
(In thousands)

Minority interest in net earnings:

CompX International Inc.                                    $    701           $    751
NL Environmental Management Services, Inc.                        30               -
--------           --------

$    731           $    751
========           ========

Note 10 - Provision for income taxes:

Three months ended
March 31,
----------------------
2005              2006
----              ----
(In millions)

Expected tax expense                                          $    7.8           $    3.4
Non-U.S. tax rates                                                 (.1)               (.1)
Incremental U.S. tax and rate differences on                                         (1.1)
equity in earnings                                               (3.8)          
Nondeductible expenses                                              .1                 -
U.S. state income taxes, net                                        .1                 .1
Excess of book basis over tax basis of Kronos                                          -
common stock sold or distributed                                 2.5         
Other, net                                                          .2                 .2
--------           --------

$    6.8           $    2.5
========           ========

Three months ended
March 31,
----------------------
2005              2006
----              ----
(In millions)
Comprehensive provision for
income taxes (benefit) allocable to:

Income from continuing operations                           $    6.8           $   2.5
Discontinued operations                                           .3                -
Retained earnings                                                3.0                -
Other comprehensive income:
Marketable securities                                          5.8               (1.3)
Currency translation                                            .3                 .5
--------           --------

$   16.2           $    1.7
========           ========

Certain  non-U.S.  tax  returns  of  Kronos  are  being  examined  and  tax
authorities  have or may  propose  tax  deficiencies,  including  penalties  and
interest. For example:

o    Kronos  received  a  preliminary  tax  assessment  related to 1993 from the
Belgian tax  authorities  proposing  tax  deficiencies,  including  related
interest,  of approximately  euro 6 million ($7 million at March 31, 2006).
Kronos filed a protest to this assessment,  and believes that a significant
portion of the  assessment is without  merit.  The Belgian tax  authorities
have filed a lien on the fixed assets of Kronos' Belgian TiO2 operations in
connection with this assessment.

o    The  Norwegian  tax  authorities  have  notified  Kronos of their intent to
assess tax  deficiencies  of  approximately  kroner 12 million ($2 million)
relating  to the years  1998  through  2000.  Kronos has  objected  to this
proposed assessment.

No  assurance  can be given  that  these  unresolved  tax  matters  will be
resolved in the Company's favor in view of the inherent  uncertainties  involved
in settlement initiatives,  court and tax proceedings. The Company believes that
it has provided  adequate  accruals for  additional  taxes and related  interest
expense which may ultimately result from all such examinations and believes that
the ultimate disposition of such examinations should not have a material adverse
effect  on  its  consolidated  financial  position,  results  of  operations  or
liquidity.

Note 11 - Employee benefit plans:

The components of net periodic  defined  benefit  pension cost (income) are
presented in the table below.

Three months ended
March 31,
----------------------
2005              2006
----              ----
(In thousands)

Interest cost                                                 $    760           $    765
Expected return on plan assets                                  (1,017)            (1,345)
Amortization of net transition obligations                         (17)               (16)
Recognized actuarial losses                                        100                 99
--------           --------

$   (174)          $   (497)
========           ========

The components of net periodic  postretirement benefits other than pensions
("OPEB") cost are presented in the table below.

Three months ended
March 31,
----------------------
2005              2006
----              ----
(In thousands)

Interest cost                                                 $    211           $    184
Amortization of prior service credit                               (72)               (28)
--------           --------

$    139           $    156
========           ========

Note 12 - Commitments and contingencies:

Lead pigment litigation. NL's former operations included the manufacture of
lead  pigments  for  use  in  paint  and  lead-based  paint.  NL,  other  former
manufacturers  of lead pigments for use in paint and lead-based paint (together,
the "former pigment manufacturers"), and the Lead Industries Association ("LIA")
(which  discontinued  business  operations  prior to 2005)  have  been  named as
defendants in various legal  proceedings  seeking  damages for personal  injury,
property damage and  governmental  expenditures  allegedly  caused by the use of
lead-based  paints.  Certain of these actions have been filed by or on behalf of
states,  large  U.S.  cities or their  public  housing  authorities  and  school
districts,  and  certain  others  have been  asserted  as class  actions.  These
lawsuits seek recovery under a variety of theories, including public and private
nuisance, negligent product design, negligent failure to warn, strict liability,
breach  of  warranty,   conspiracy/concert   of  action,  aiding  and  abetting,
enterprise liability,  market share or risk contribution liability,  intentional
tort,  fraud and  misrepresentation,  violations  of state  consumer  protection
statutes, supplier negligence and similar claims.

The plaintiffs in these actions  generally seek to impose on the defendants
responsibility for lead paint abatement and health concerns  associated with the
use of lead-based  paints,  including damages for personal injury,  contribution
and/or  indemnification  for medical expenses,  medical monitoring  expenses and
costs for  educational  programs.  A number of cases are  inactive  or have been
dismissed or  withdrawn.  Most of the remaining  cases are in various  pre-trial
stages.  Some are on appeal  following  dismissal or summary judgment rulings in
favor of either the defendants or plaintiffs.  In addition,  various other cases
are pending  (in which NL is not a  defendant)  seeking  recovery  for  injuries
allegedly  caused by lead  pigment and  lead-based  paint.  Although NL is not a
defendant in these cases, the outcome of these cases may have an impact on cases
that might be filed against NL in the future.

NL believes  these actions are without  merit,  intends to continue to deny
all  allegations  of wrongdoing  and liability and to defend against all actions
vigorously.  NL has never settled any of these cases, nor have any final adverse
judgments  been  entered  against NL. NL has not accrued any amounts for pending
lead pigment and lead-based paint litigation. Liability that may result, if any,
cannot currently be reasonably estimated. There can be no assurance that NL will
not incur liability in the future in respect of this pending  litigation in view
of the inherent  uncertainties involved in court and jury rulings in pending and
possible  future cases.  If any such future  liability  were to be incurred,  it
could have a material  adverse  effect on the Company's  consolidated  financial
position, results of operations and liquidity.

In one of  these  lead  pigment  cases  (State  of  Rhode  Island  v.  Lead
Industries Association), a trial before a Rhode Island state court jury began in
September  2002 on the question of whether lead pigment in paint on Rhode Island
buildings is a public  nuisance.  In October  2002,  the trial judge  declared a
mistrial  in the  case  when  the jury was  unable  to  reach a  verdict  on the
question,  with the jury reportedly  deadlocked 4-2 in the defendants' favor. In
November  2005,  the State of Rhode  Island  began a retrial  of the case on the
State's claims of public nuisance,  indemnity and unjust  enrichment  against NL
and three other defendants.  Following the State's presentation of its case, the
trial court dismissed the State's claims of indemnity and unjust enrichment. The
public  nuisance claim was sent to the jury in February 2006, and the jury found
that NL and two other defendants substantially  contributed to the creation of a
public  nuisance  as a result of the  collective  presence  of lead  pigments in
paints and coatings on buildings  in Rhode  Island.  The jury also found that NL
and the two other  defendants  should be ordered  to abate the public  nuisance.
Following  the jury  verdict,  the trial court  dismissed  the State's claim for
punitive  damages.  The scope of the abatement  remedy will be determined by the
judge.  The extent,  nature and cost of such remedy is not  currently  known and
will be determined only following additional proceedings. Various matters remain
pending before the trial court,  including NL's motion to dismiss. NL intends to
appeal any adverse judgment which the trial court may enter against NL.

The Rhode  Island  case is  unique  in that this is the first  time that an
adverse  verdict in the lead pigment  litigation has been entered against NL. NL
does not believe it is currently  possible to determine  the nature or extent of
any potential liability resulting from the verdict. In addition,  liability that
might  result to NL, if any,  with  respect to this and the other  lead  pigment
litigation can not currently be reasonably estimated. However, legal proceedings
are subject to inherent uncertainties, and there is no assurance that any appeal
would be  successful.  Therefore it is reasonably  possible that NL would in the
near term conclude  that it was probable NL had incurred some  liability in this
Rhode Island matter that would result in the  recognition of a loss  contingency
accrual.  Such potential  liability could have a material  adverse impact on net
income  for the  interim  or  annual  period  during  which  such  liability  is
recognized,  and a  material  adverse  impact on NL's  financial  condition  and
liquidity.  Various  other cases in which NL is a defendant  are also pending in
other jurisdictions,  and new cases could be filed against NL, the resolution of
which could also result in recognition of a loss contingency  accrual that could
have a material  adverse  impact on net income for the interim or annual  period
during which such liability is recognized, and a material adverse impact on NL's
financial  condition and liquidity.  An estimate of the potential impact on NL's
results of operations, financial condition or liquidity related to these matters
can not currently be reasonably estimated.

Environmental matters and litigation. The Company's operations are governed
by  various  environmental  laws  and  regulations.  Certain  of  the  Company's
businesses  are and have been  engaged in the  handling,  manufacture  or use of
substances  or compounds  that may be considered  toxic or hazardous  within the
meaning of applicable  environmental  laws. As with other  companies  engaged in
similar  businesses,  certain  past and current  operations  and products of the
Company have the potential to cause  environmental or other damage.  The Company
has implemented and continues to implement  various  policies and programs in an
effort to minimize these risks. The Company's  policy is to maintain  compliance
with applicable  environmental  laws and regulations at all of its plants and to
strive to improve environmental performance.  From time to time, the Company may
be subject to  environmental  regulatory  enforcement  under  U.S.  and  foreign
statutes, resolution of which typically involves the establishment of compliance
programs. It is possible that future developments, such as stricter requirements
of  environmental  laws and  enforcement  policies  thereunder,  could adversely
affect the Company's production, handling, use, storage, transportation, sale or
disposal  of such  substances.  The  Company  believes  all of its plants are in
substantial compliance with applicable environmental laws.

Certain  properties and facilities used in the Company's former businesses,
including  divested  primary  and  secondary  lead  smelters  and former  mining
locations of NL, are the subject of civil litigation, administrative proceedings
or  investigations   arising  under  federal  and  state   environmental   laws.
Additionally,  in connection with past disposal practices,  the Company has been
named as a defendant, potentially responsible party ("PRP") or both, pursuant to
the  Comprehensive  Environmental  Response,  Compensation and Liability Act, as
amended by the Superfund  Amendments and  Reauthorization  Act  ("CERCLA"),  and
similar state laws in various  governmental and private actions  associated with
waste disposal sites, mining locations,  and facilities  currently or previously
owned,  operated  or  used  by  the  Company  or  its  subsidiaries,   or  their
predecessors,  certain  of  which  are  on the  U.S.  EPA's  Superfund  National
Priorities List or similar state lists.  These  proceedings  seek cleanup costs,
damages for  personal  injury or property  damage  and/or  damages for injury to
natural resources.  Certain of these proceedings  involve claims for substantial
amounts.  Although  the  Company may be jointly  and  severally  liable for such
costs,  in most cases it is only one of a number of PRPs who may also be jointly
and severally liable.

Environmental obligations are difficult to assess and estimate for numerous
reasons including the complexity and differing  interpretations  of governmental
regulations,  the number of PRPs and the PRPs'  ability or  willingness  to fund
such  allocation of costs,  their financial  capabilities  and the allocation of
costs among PRPs,  the  solvency of other  PRPs,  the  multiplicity  of possible
solutions,  and the years of  investigatory,  remedial and  monitoring  activity
required.   In  addition,   the  imposition  of  more  stringent   standards  or
requirements  under  environmental  laws or  regulations,  new  developments  or
changes  respecting  site cleanup  costs or allocation of such costs among PRPs,
solvency of other PRPs,  the results of future  testing and analysis  undertaken
with respect to certain sites or a determination that the Company is potentially
responsible for the release of hazardous substances at other sites, could result
in  expenditures in excess of amounts  currently  estimated by the Company to be
required for such matters. In addition,  with respect to other PRPs and the fact
that the Company may be jointly and severally  liable for the total  remediation
cost at certain  sites,  the Company  could  ultimately be liable for amounts in
excess of its accruals due to, among other things,  reallocation  of costs among
PRPs or the  insolvency  of one or more  PRPs.  No  assurance  can be given that
actual costs will not exceed  accrued  amounts or the upper end of the range for
sites for which  estimates  have been made,  and no assurance  can be given that
costs  will not be  incurred  with  respect  to  sites  as to which no  estimate
presently  can be made.  Further,  there  can be no  assurance  that  additional
environmental matters will not arise in the future. If any such future liability
were to be incurred,  it could have a material  adverse  effect on the Company's
consolidated financial statements, results of operations and liquidity.

The  Company  records  liabilities  related  to  environmental  remediation
obligations  when  estimated  future  expenditures  are probable and  reasonably
estimable.  Such accruals are adjusted as further  information becomes available
or  circumstances  change.  Estimated  future  expenditures  are  generally  not
discounted to their present value.  Recoveries of  remediation  costs from other
parties, if any, are recognized as assets when their receipt is deemed probable.
At March 31, 2006, no receivables for recoveries had been recognized.

The exact time frame over which the Company makes  payments with respect to
its accrued  environmental  costs is unknown and is dependent upon,  among other
things,  the timing of the actual  remediation  process which in part depends on
factors  outside the control of the  Company.  At each balance  sheet date,  the
Company makes an estimate of the amount of its accrued environmental costs which
will be paid out over the subsequent 12 months,  and the Company classifies such
amount as a current liability.  The remainder of the accrued environmental costs
is classified as a noncurrent liability.

A summary of the  activity in the  Company's  accrued  environmental  costs
during the first quarter of 2006 is presented in the table below.

Amount
--------------
(In thousands)

Balance at the beginning of the period                                        $ 54,947
Additions charged (credited) to expense, net                                      (142)
Payments, net                                                                   (1,910)
--------

Balance at the end of the period                                              $ 52,895
========

Amounts recognized in the balance sheet 
at the end of the period:
Current liability                                                        $ 12,028
Noncurrent liability                                                       40,867
--------

$ 52,895
========

On a quarterly  basis,  the Company  evaluates the  potential  range of its
liability at sites where it has been named as a PRP or  defendant.  At March 31,
2006,  the Company had accrued  $52.9  million for those  environmental  matters
which the Company believes are reasonably estimable.  The Company believes it is
not possible to estimate the range of costs for certain sites.  The upper end of
the range of  reasonably  possible  costs to the Company for sites for which the
Company believes it is possible to estimate costs is approximately  $79 million.
The Company's  estimates of such liabilities have not been discounted to present
value.

At March 31, 2006,  there are  approximately 20 sites for which the Company
is  unable  to  estimate  a range of  costs.  For  these  sites,  generally  the
investigation is in the early stages,  and it is either unknown as to whether or
not the Company  actually had any  association  with the site, or if the Company
had an association with the site, the nature of its responsibility,  if any, for
the  contamination  at the site and the extent of  contamination.  The timing on
when  information  would become available to the Company to allow the Company to
estimate a range of loss is unknown and dependent on events  outside the control
of the Company,  such as when the party alleging liability provides  information
to the Company. On certain of these sites that had previously been inactive,  NL
has received general and special notices of liability from the EPA alleging that
NL, along with other PRPs,  is liable for past and future  costs of  remediating
environmental  contamination  allegedly caused by former operations conducted at
such sites.  These  notifications  may assert that NL, along with other PRPs, is
liable for past  clean-up  costs that could be material to NL if  liability  for
such amounts ultimately were determined against NL.

Other  litigation.  Reference  is  made to the  2005  Annual  Report  for a
discussion of certain other legal proceedings to which the Company is a party.

NL has been  named as a  defendant  in  various  lawsuits  in a variety  of
jurisdictions,  alleging personal injuries as a result of occupational  exposure
primarily to products manufactured by formerly-owned operations of NL containing
asbestos,  silica and/or mixed dust.  Approximately  500 of these types of cases
remain pending,  involving a total of approximately  10,600 plaintiffs and their
spouses following the administrative  dismissal of approximately 1,500 claims of
plaintiffs  in March 2006.  NL has not  accrued any amounts for this  litigation
because  liability that NL might incur, if any,  cannot  currently be reasonably
estimated.  To date, NL has not been adjudicated liable in any of these matters.
Based on information  available to NL, including facts concerning its historical
operations,  the rate of new claims, the number of claims from which NL has been
dismissed and NL's prior experience in the defense of these matters, NL believes
that  the  range of  reasonably  possible  outcomes  of  these  matters  will be
consistent with NL's  historical  costs with respect to these matters (which are
not material), and no reasonably possible outcome is expected to involve amounts
that are material to NL. NL has and will continue to vigorously  seek  dismissal
from  each  claim  and/or a  finding  of no  liability  by NL in each  case.  In
addition,  from time to time,  NL has  received  notices  regarding  asbestos or
silica  claims  purporting  to be brought  against  former  subsidiaries  of NL,
including   notices  provided  to  insurers  with  which  NL  has  entered  into
settlements  extinguishing  certain insurance policies.  These insurers may seek
indemnification from NL.

In April  2006,  NL was served  with a  complaint  in Murphy,  et al. v. NL
Industries,  Inc., et al. (United States District Court, District of New Jersey,
Case  No.   2:06-cv-01535-WHW-SDW).   The  plaintiffs,   three  former  minority
shareholders of NL Environmental Management Services, Inc. ("EMS"), seek damages
related to their equity investment in EMS. The defendants named in the complaint
are Contran,  Valhi, NL, EMS and certain current or former officers or directors
of NL  or  EMS.  EMS  was  formed  in  1998  as a  majority-owned  environmental
management  subsidiary that contractually  assumed certain of NL's environmental
liabilities.  In June  2005,  EMS  received  notices  from  the  three  minority
shareholders  indicating  that they were  exercising  their right,  which became
exercisable on June 1, 2005, to require EMS to purchase their  preferred  shares
in EMS as of June 30, 2005 for a  formula-determined  amount as provided in EMS'
certificate   of   incorporation.   In  accordance   with  the   certificate  of
incorporation,  EMS made a determination  in good faith of the amount payable to
the three former minority shareholders to purchase their shares of EMS stock. In
June 2005 EMS set aside  funds as  payment  for the  shares of EMS.  As of March
2006, however, the shareholders had not tendered their shares or received any of
such funds.  The  plaintiffs  claim that,  in  preparing  the  valuation  of the
plaintiffs'  preferred  shares for purchase by EMS, the defendants  engaged in a
pattern of racketeering  activity and a conspiracy in violation of United States
and New Jersey laws. In addition, the plaintiffs allege that the defendants have
committed  minority  shareholder  oppression,  fraud,  breach of fiduciary duty,
civil  conspiracy,  aiding and abetting  fraud,  aiding and  abetting  breach of
fiduciary  duty,  breach of contract and  tortious  interference  with  economic
relations  under New Jersey laws. The  defendants  believe that these claims are
without merit and intend to deny all allegations of wrongdoing and liability and
to defend against all such claims vigorously.

In  addition  to the  litigation  described  above,  the  Company  and  its
affiliates  are also  involved  in  various  other  environmental,  contractual,
product  liability,  patent (or  intellectual  property),  employment  and other
claims and disputes incidental to its present and former businesses.  In certain
cases,  the Company has insurance  coverage for such items;  however the Company
does  not  currently  expect   additional   material   insurance   coverage  for
environmental claims.

The  Company  currently  believes  that the  disposition  of all claims and
disputes,  individually or in the aggregate,  should not have a material adverse
effect  on  its  consolidated  financial  position,  results  of  operations  or
liquidity beyond the accruals already provided for.

Insurance coverage claims

Reference  is made to the 2005 Annual  Report for a  discussion  of certain
litigation involving NL and certain of its former insurance carriers. Additional
information regarding such litigation, or new litigation, is below.

OneBeacon  American  Insurance  Company  v. NL  Industries,  Inc.,  et. al.
(Supreme  Court  of the  State  of New  York,  County  of New  York,  Index  No.
603429-05). In March 2006, NL's motion to dismiss was denied by the trial court.
In April 2006, NL filed a notice of appeal of the trial court's ruling.

NL  Industries,  Inc.  v.  OneBeacon  America  Insurance  Company,  et. al.
(District Court for Dallas County, Texas, Case No. 05-11347).  In December 2005,
NL filed a motion to remand the case to state court.

In February 2006, NL was served with a complaint in Certain Underwriters at
Lloyds, London v. Millennium Holdings LLC et. al. (Supreme Court of the State of
New York,  County of New York,  Index No.  06/60026).  The  plaintiff,  a former
insurance  carrier of NL, seeks a declaratory  judgment of its obligations to NL
under insurance  policies issued to NL by plaintiff with respect to certain lead
pigment lawsuits. In April 2006, NL filed a motion to dismiss.

In April 2006, NL filed an action against  Certain  Underwriters at Lloyds,
London and certain other former  insurance  companies,  captioned NL Industries,
Inc. v.  American Re Insurance  Company,  et. al.  (Dallas  County Court at Law,
Texas, Case No. CC-06-04523-E) asserting that the defendants have breached their
obligations to NL under such insurance policies with respect to lead pigment and
asbestos  claims  and  seeking  a  declaratory   judgment  of  each  defendant's
obligations to NL under such policies.

The issue of whether  insurance  coverage for defense costs or indemnity or
both will be found to exist  for NL's lead  pigment  litigation  depends  upon a
variety of factors,  and there can be no assurance that such insurance  coverage
will be available.  NL has not considered any potential insurance recoveries for
lead  pigment  or  environmental   litigation  matters  in  determining  related
accruals.

Note 13 - Discontinued operations:

Discontinued  operations relates to CompX's former Thomas Regout operations
in the Netherlands. In January 2005, CompX completed the sale of such operations
for net proceeds that were approximately $860,000 less than previously estimated
(primarily  due to higher  expenses  associated  with the disposal of the Thomas
Regout  operations),  and  discontinued  operations in the first quarter of 2005
includes a charge  related  to such  differential  ($272,000,  net of income tax
benefit and minority interest).

Note 14 - Accounting principles newly adopted in 2006:

Inventory  costs.  The Company  adopted  Statement of Financial  Accounting
Standards  ("SFAS")  No. 151,  "Inventory  Costs,  an  amendment  of ARB No. 43,
Chapter 4," as of January 1, 2006 for inventory  costs incurred on or after such
date.  SFAS No. 151 requires that the  allocation of fixed  production  overhead
costs to inventory  shall be based on normal  capacity.  Normal  capacity is not
defined  as a fixed  amount;  rather,  normal  capacity  refers  to a  range  of
production  levels expected to be achieved over a number of periods under normal
circumstances,  taking into account the loss of capacity  resulting from planned
maintenance  shutdowns.  The amount of fixed overhead  allocated to each unit of
production is not increased as a consequence of idle plant or production  levels
below the low end of normal  capacity,  but instead a portion of fixed  overhead
costs is charged to expense as incurred. Alternatively, in periods of production
above the high end of  normal  capacity,  the  amount  of fixed  overhead  costs
allocated to each unit of  production is decreased so that  inventories  are not
measured above cost.  SFAS No. 151 also clarifies  existing GAAP to require that
abnormal freight and wasted materials (spoilage) are to be expensed as incurred.
The  Company's   production  cost  accounting  had  already  complied  with  the
requirements  of SFAS No. 151,  and  therefore  adoption of SFAS No. 151 did not
have a material effect on its consolidated financial statements.

Stock  options.  As permitted by regulations of the Securities and Exchange
Commission ("SEC") the Company adopted SFAS No. 123R,  "Share-Based Payment," as
of  January  1,  2006.  SFAS  No.  123R,  among  other  things,  eliminates  the
alternative in existing GAAP to use the intrinsic value method of accounting for
stock-based  employee  compensation  under  Accounting  Principles Board Opinion
("APBO")  No. 25,  "Accounting  for Stock Issued to  Employees".  The Company is
generally  required  to  recognize  the cost of  employee  services  received in
exchange for an award of equity  instruments  based on the grant-date fair value
of the award,  with the cost recognized over the period during which an employee
is required to provide  services in exchange  for the award  (generally,  if the
vesting  period of the award).  No  compensation  cost will be recognized in the
aggregate  for equity  instruments  for which the  employee  does not render the
requisite service (generally, the instrument is forfeited before it has vested).
The grant-date  fair value will be estimated using  option-pricing  models (e.g.
Black-Scholes or a lattice model). Under the transition  alternatives  permitted
under SFAS No.  123R,  the Company will apply the new standard to all new awards
granted on or after January 1, 2006,  and to all awards  existing as of December
31, 2005 which are subsequently modified,  repurchased or cancelled (referred to
as the  modified  prospective  method  in SFAS No.  123R).  Additionally,  as of
January 1, 2006, the Company recognizes compensation cost for the portion of any
non-vested  award  existing as of December 31, 2005 over the  remaining  vesting
period.  Because the number of  non-vested  awards as of December  31, 2005 with
respect to options  granted by NL was not material,  the effect of adopting SFAS
No.  123R,  in so far as it relates to existing  stock  options,  did not have a
material effect on the Company's consolidated financial statements. Should NL or
its subsidiaries and affiliates,  however,  either grant a significant number of
options or modify,  repurchase  or cancel  existing  options in the future,  the
effect on the Company's consolidated financial statements could be material.

Under  SFAS No.  123R,  the cash  income  tax  benefit  resulting  from the
exercise of stock options in excess of the cumulative income tax benefit related
to such options previously  recognized for GAAP financial  reporting purposes in
the Company's consolidated  statements of income, if any, is reflected as a cash
inflow from  financing  activities in the Company's  consolidated  statements of
cash flows, and the Company's cash flows from operating  activities reflects the
effect of cash paid for income taxes  exclusive of such cash income tax benefit.
The  aggregate  amount of such income tax benefits  recognized as a component of
cash flows from financing activities was nil in the first quarter of 2006.

SFAS No. 123R also  requires  certain  expanded  disclosures  regarding the
Company's stock options, and such expanded disclosures were provided in the 2005
Annual Report.

Prior to January 1, 2006, the Company  accounted for  stock-based  employee
compensation  in accordance  with APBO No. 25, and its various  interpretations.
Under APBO No. 25, no compensation cost is generally  recognized for fixed stock
options in which the exercise price is greater than or equal to the market price
on the grant date.  Prior to 2005, and following the cash  settlement of certain
stock options held by employees of NL, the Company commenced  accounting for its
stock options using the variable  accounting  method of APBO No. 25,  because NL
could not overcome the  presumption  that it would not similarly cash settle its
remaining stock options.  Under the variable  accounting  method,  the intrinsic
value of all unexercised stock options (including stock options with an exercise
price at least equal to the market  price on the date of grant) is accrued as an
expense,  with subsequent  increases  (decreases) in the Company's  market price
resulting  in the  recognition  of  additional  compensation  expense  (income).
Following  adoption of SFAS No. 123R effective January 1, 2006, the Company will
continue to account for its remaining  stock options in a manner  similar to the
variable  accounting  method of APBO No. 25, as required by the guidance of SFAS
No. 123R.

Net compensation cost recognized by the Company in accordance with APBO No.
25 was not significant in the first quarter of 2005, and net compensation income
recognized  by the Company was  approximately  $200,000 in the first  quarter of
2006.

If the Company and its  subsidiaries  and  affiliates  had each  elected to
account for their respective  stock-based employee compensation related to stock
options in accordance with the fair value-based  recognition  provisions of SFAS
No. 123  for all awards granted subsequent to January 1, 1995, the effect on the
Company's results of operations in the first quarter of 2005 would not have been
material.

Note 15 - Accounts with affiliates:

December 31,           March 31,
2005                 2006
------------          ----------
(In thousands)

Current receivables from affiliates:

Income taxes receivable from Valhi                           $  3,146            $  2,087
Kronos - trade items                                              145                 464
--------            --------

$  3,291            $  2,551
========            ========

Current payables to affiliates:
Income taxes payable to Valhi                                $    771            $    917
Tremont Corporation - trade items                                 211                 221
--------            --------

$    982            $  1,138
========            ========

ITEM 2. MANAGEMENT'S  DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
OF OPERATIONS
--------------------------------------------------------------------------------

RESULTS OF OPERATIONS:

General

The Company reported net income of $6.5 million, or $.13 per diluted share,
in the first  quarter of 2006 compared to income of $14.5  million,  or $.30 per
diluted share, in the first quarter of 2005.

The  decrease in the  Company's  diluted  earnings per share from the first
quarter of 2005  compared to the first  quarter of 2006 is due  primarily to the
net effects of (i) higher component products income from operations,  (ii) lower
earnings attributable to Kronos, (iii) security transactions gains from the sale
of shares of Kronos  common  stock in the first  quarter  of 2005 and (iv) lower
corporate expense. The Company currently believes its net income in 2006 will be
lower than 2005 due  primarily  to the  effects of  security  transaction  gains
recognized in 2005 and lower earnings attributable to Kronos.

Income from  continuing  operations  in the first  quarter of 2006 includes
income  of $.03 per  diluted  share  related  to  certain  insurance  recoveries
received by the Company.  Income from continuing operations in the first quarter
of 2005 includes income of $.16 per diluted share related to the Company's sales
of shares of Kronos common stock. Such amounts are more fully described below or
in the 2005 Annual Report.

As  provided  by the  safe  harbor  provisions  of the  Private  Securities
Litigation  Reform Act of 1995, the Company cautions that the statements in this
Quarterly Report on Form 10-Q relating to matters that are not historical facts,
are  forward-looking   statements  that  represent   management's   beliefs  and
assumptions based on currently available information. Forward-looking statements
can be  identified  by the use of words such as  "believes,"  "intends,"  "may,"
"should," "could," "anticipates,"  "expected" or comparable  terminology,  or by
discussions  of  strategies  or trends.  Although the Company  believes that the
expectations  reflected in such  forward-looking  statements are reasonable,  it
cannot give any  assurances  that these  expectations  will prove to be correct.
Such statements by their nature involve substantial risks and uncertainties that
could  significantly  impact expected  results,  and actual future results could
differ materially from those described in such forward-looking statements. While
it is not possible to identify all factors,  the Company  continues to face many
risks and  uncertainties.  The factors that could cause actual future results to
differ  materially from those described  herein are the risks and  uncertainties
discussed in this Quarterly  Report and those described from time to time in the
Company's  other  filings  with the SEC  include,  but are not  limited  to, the
following:

o    Future supply and demand for the Company's products,
o    The extent of the  dependence  of certain of the  Company's  businesses  on
certain market sectors,
o    The  cyclicality  of  the  Company's   businesses  (such  as  Kronos'  TiO2
operations),
o    Customer  inventory  levels (such as the extent to which Kronos'  customers
may,  from  time to  time,  accelerate  purchases  of TiO2  in  advance  of
anticipated  price  increases  or defer  purchases  of TiO2 in  advance  of
anticipated price decreases),
o    Changes in raw material and other operating costs (such as energy and steel
costs),
o    The possibility of labor disruptions,
o    General global  economic and political  conditions  (such as changes in the
level of gross  domestic  product in  various  regions of the world and the
impact of such changes on demand for TiO2 and component products),
o    Demand for office furniture,
o    Competitive   products  and  substitute   products,   including   increased
competition from low-cost manufacturing sources (such as China),
o    Customer and competitor strategies,
o    The impact of pricing and production decisions,
o    Competitive technology positions,
o    Service industry employment levels,
o    Fluctuations  in currency  exchange  rates (such as changes in the exchange
rate between the U.S.  dollar and each of the euro,  the Norwegian  kroner,
the New Taiwan dollar and the Canadian dollar),
o    Operating  interruptions  (including,  but not limited to, labor  disputes,
leaks,  natural  disasters,  fires,  explosions,  unscheduled  or unplanned
downtime and transportation interruptions),
o    The timing and amounts of insurance recoveries,
o    The ability of the Company to renew or refinance credit facilities,
o    The ultimate  outcome of income tax audits,  tax settlement  initiatives or
other tax matters,
o    The introduction of trade barriers,
o    Potential difficulties in integrating completed or future acquisitions,
o    Decisions to sell  operating  assets  other than in the ordinary  course of
business,
o    Uncertainties associated with new product development,
o    The ultimate ability to utilize income tax attributes, the benefit of which
has been recognized under the "more-likely-than-not" recognition criteria,
o    Environmental  matters  (such as those  requiring  emission  and  discharge
standards for existing and new facilities),
o    Government  laws and  regulations  and possible  changes  therein  (such as
changes in government regulations which might impose various obligations on
present and former  manufacturers  of lead  pigment and  lead-based  paint,
including NL, with respect to asserted health concerns  associated with the
use of such products),
o    The ultimate  resolution of pending  litigation  (such as NL's lead pigment
litigation and litigation surrounding environmental matters), and
o    Possible future litigation.

Should one or more of these risks  materialize (or the consequences of such
a development  worsen),  or should the underlying  assumptions  prove incorrect,
actual results could differ  materially from those  forecasted or expected.  The
Company   disclaims  any  intention  or  obligation  to  update  or  revise  any
forward-looking statement whether as a result of changes in information,  future
events or otherwise.

CompX International Inc.

Three months ended
March 31,
----------------------          %  
2005              2006        Change    
----              ----        ------
(In millions)

Net sales                                                      $ 46.8            $ 47.0            *
Income from operations attributable to CompX                      4.1               4.8         +17%

_________________________

*  less than 1% increase

Component product sales increased  slightly in the first quarter of 2006 as
compared to the same quarter of 2005 as higher volumes of security product sales
were offset by  decreases in sales for certain  other  products  resulting  from
increased  competition.  Component products income from operations increased due
to the favorable impact of CompX's  continued focus on reducing costs across all
segments and a favorable change in product mix resulting from increases in sales
of certain higher margin security products.

CompX has  substantial  operations  and assets  located  outside the United
States in Canada  and  Taiwan.  A portion of CompX's  sales  generated  from its
non-U.S.  operations are denominated in currencies  other than the U.S.  dollar,
principally  the  Canadian  dollar and the New Taiwan  dollar.  In  addition,  a
portion of CompX's sales generated from its non-U.S.  operations (principally in
Canada) are denominated in the U.S. dollar. Most raw materials,  labor and other
production costs for such non-U.S. operations are denominated primarily in local
currencies.  Consequently,  the translated U.S. dollar values of CompX's foreign
sales and operating  results are subject to currency  exchange rate fluctuations
which may  favorably  or  unfavorably  impact  reported  earnings and may affect
comparability of  period-to-period  operating  results.  Fluctuations in foreign
currency exchange rates did not have a significant  effect on sales or operating
income in the first quarter of 2006 as compared to the first quarter of 2005.

The component product areas where CompX operates are highly  competitive in
terms of product  pricing and  features.  CompX's  strategy is to focus on areas
where it can  provide  products  that have  value-added,  user-oriented-features
which enable its customers to compete more effectively in their markets.  One of
the focal  points of this  strategy  is to replace low  margin,  commodity  type
products with higher margin user-oriented feature products.  Additionally, CompX
believes that its focus on  collaborating  with customers to identify  solutions
and its ability to provide a high level of customer service enable it to compete
effectively.  In response to competitive  pricing pressure,  CompX  continuously
focuses on reducing production cost through product  reengineering,  improvement
in manufacturing processes or moving production to lower cost facilities.

Raw  material  prices,  especially  steel,  zinc and copper  continue to be
volatile putting  pressure on CompX's margins.  CompX actively seeks to mitigate
the margin  impact by entering into raw material  supply  agreements in order to
stabilize the cost for a period of time,  execute  larger  volume  tactical spot
purchases at prices that are expected to be favorable  compared to future prices
and, if necessary,  pass on the cost increases to customers  through  surcharges
and price increases.

Equity in earnings of Kronos Worldwide, Inc.

Three months ended
March 31,
----------------------          %  
2005              2006        Change    
----              ----        ------
(In millions)

Kronos historical:

Net sales                                                     $291.9           $304.3            +4%
======           ======

Income from operations                                        $ 46.5           $ 34.4           -26%
Other general corporate, net                                      .4               .6
Interest expense                                               (11.8)           (10.7)
------           ------
35.1             24.3

Income tax expense                                              13.7              9.3
------           ------

Net income                                                  $ 21.4           $ 15.0
======           ======

Equity in earnings of Kronos Worldwide, Inc.                  $  7.8           $  5.4
======           ======

TiO2 operating statistics:
Sales volumes*                                                   114              124            +9%
Production volumes*                                              122              127            +4%

Percentage change in Ti02 average selling                                   
prices:                                                                    
Using actual foreign currency exchange rates                                                   -3%
Impact of changes in foreign currency                                                                      
exchange rates                                                                                +5%
---

In billing currencies                                                                          +2%
===

_______________________________

* Thousands of metric tons

Relative  changes in Kronos' TiO2 sales and income from  operations  during
the 2005 and 2006 periods presented are primarily due to (i) relative changes in
TiO2 average selling prices,  (ii) relative changes in selling volumes and (iii)
relative changes in foreign currency exchange rates.  Selling prices (in billing
currencies) for TiO2, Kronos' principal product,  were generally:  increasing in
the first half of 2005,  decreasing  during the last half of 2005 and increasing
during the first quarter of 2006.

Kronos'  sales  increased  $12.4  million (4%) in the first quarter of 2006
compared to the first  quarter of 2005 due to the net effects of higher  average
TiO2 selling prices (in billing currencies), higher TiO2 selling volumes and the
unfavorable  effect of fluctuations in foreign  currency  exchange rates,  which
decreased  sales by  approximately  $16  million,  as further  discussed  below.
Excluding the effect of fluctuations in the value of the U.S. dollar relative to
other currencies,  Kronos' average TiO2 selling prices in billing  currencies in
the first  quarter of 2006 were 2% higher as  compared  to the first  quarter of
2005.  When  translated  from billing  currencies  to U.S.  dollars using actual
foreign  currency  exchange  rates  prevailing  during the  respective  periods,
Kronos'  average TiO2 selling  prices in the first quarter of 2006  decreased 3%
compared to the first quarter of 2005.

Kronos' sales are  denominated  in various  currencies,  including the U.S.
dollar,  the euro, other major European  currencies and the Canadian dollar. The
disclosure of the  percentage  change in Kronos'  average TiO2 selling prices in
billing  currencies  (which excludes the effects of fluctuations in the value of
the U.S.  dollar  relative  to other  currencies)  is  considered  a  "non-GAAP"
financial measure under regulations of the SEC. The disclosure of the percentage
change in Kronos'  average TiO2 selling  prices  using actual  foreign  currency
exchange rates prevailing  during the respective  periods is considered the most
directly  comparable  financial measure presented in accordance with GAAP ("GAAP
measure").  Kronos  discloses  percentage  changes in its average TiO2 prices in
billing  currencies  because Kronos  believes such  disclosure  provides  useful
information  to  investors  to allow them to analyze  such  changes  without the
impact of changes in  foreign  currency  exchange  rates,  thereby  facilitating
period-to-period  comparisons of the relative  changes in average selling prices
in the actual various billing currencies. Generally, when the U.S. dollar either
strengthens  or weakens  against  other  currencies,  the  percentage  change in
average  selling  prices  in  billing   currencies  will  be  higher  or  lower,
respectively,  than such percentage changes would be using actual exchange rates
prevailing during the respective periods. The difference between the 3% decrease
in Kronos'  average  TiO2  selling  prices  during the first  quarter of 2006 as
compared to the first  quarter of 2005 using actual  foreign  currency  exchange
rates prevailing  during the respective  periods (the GAAP measure),  and the 2%
increase in Kronos'  average  TiO2  selling  prices in billing  currencies  (the
non-GAAP measure) during such periods is due to the effect of changes in foreign
currency  exchange  rates.  The above table presents in a tabular format (i) the
percentage  change in Kronos'  average TiO2 selling  prices using actual foreign
currency  exchange  rates  prevailing  during the  respective  periods (the GAAP
measure),  (ii) the percentage  change in Kronos' average TiO2 selling prices in
billing currencies (the non-GAAP measure) and (iii) the percentage change due to
changes in foreign currency  exchange rates (or the reconciling item between the
non-GAAP measure and the GAAP measure).

Kronos'  TiO2 sales  volumes  in the first  quarter  of 2006  increased  9%
compared to the first quarter of 2005,  due primarily to higher sales volumes in
the United  States and  slightly  higher  sales  volumes in Europe and in export
markets offsetting the effects of lower sales volumes in Canada. Demand for TiO2
has remained strong in the first quarter of 2006, and while Kronos believes that
the strong demand for TiO2 is largely  attributable to the end-use demand of its
customers,  it is possible that some portion of the strong demand  resulted from
customers increasing their inventory levels of TiO2 in advance of implementation
of announced or anticipated  price  increases.  Kronos'  income from  operations
comparisons were favorably impacted by higher production levels, which increased
4% in the first quarter of 2006 as compared to the same period in 2005.  Kronos'
operating rates were near full capacity in both periods,  and Kronos' production
and sales volumes in the first quarter of 2006 were new records for Kronos for a
first quarter.

Kronos has  substantial  operations and assets  located  outside the United
States (primarily in Germany,  Belgium, Norway and Canada). A significant amount
of Kronos' sales  generated  from its non-U.S.  operations  are  denominated  in
currencies  other  than the U.S.  dollar,  principally  the  euro,  other  major
European  currencies  and the  Canadian  dollar.  A  portion  of  Kronos'  sales
generated  from its non-U.S.  operations  are  denominated  in the U.S.  dollar.
Certain raw materials,  primarily titanium-containing  feedstocks, are purchased
in U.S.  dollars,  while  labor  and  other  production  costs  are  denominated
primarily in local currencies. Consequently, the translated U.S. dollar value of
Kronos'  foreign  sales and operating  results are subject to currency  exchange
rate fluctuations  which may favorably or adversely impact reported earnings and
may affect the comparability of  period-to-period  operating  results.  Overall,
fluctuations  in the  value of the U.S.  dollar  relative  to other  currencies,
primarily  the euro,  decreased  TiO2  sales by a net $16  million  in the first
quarter of 2006 as compared to the first  quarter of 2005.  Fluctuations  in the
value of the U.S. dollar relative to other currencies similarly impacted Kronos'
foreign  currency-denominated  operating expenses.  Kronos' operating costs that
are not denominated in the U.S. dollar, when translated into U.S. dollars,  were
higher in the first  quarter  of 2006 as  compared  to the same  period in 2005.
Overall,  currency exchange rate fluctuations resulted in approximately a net $5
million  decrease in Kronos' income from operations in the first quarter of 2006
as compared to the first quarter of 2005.

On September  22, 2005,  the  chloride-process  TiO2  facility  operated by
Kronos' 50%-owned joint venture, Louisiana Pigment Company ("LPC"),  temporarily
halted  production  due  to  Hurricane  Rita.  Although  storm  damage  to  core
processing facilities was not extensive, a variety of factors, including loss of
utilities,  limited  access and  availability  of employees  and raw  materials,
prevented the  resumption of partial  operations  until October 9, 2005 and full
operations  until late 2005.  The joint  venture  expects  the  majority  of its
property  damage  and  unabsorbed  fixed  costs  for  periods  in  which  normal
production  levels were not achieved  will be covered by  insurance,  and Kronos
believes   insurance  will  cover  its  lost  profits   (subject  to  applicable
deductibles) resulting from its share of the lost production from LPC. Insurance
proceeds  from the lost profit for product that Kronos was not able to sell as a
result of the loss of  production  from LPC are  expected  to be  recognized  by
Kronos  during the  remainder  of 2006,  although  the amount and timing of such
insurance  recoveries  is not  presently  determinable.  The  effect on  Kronos'
financial results will depend on the timing and amount of insurance recoveries.

Kronos' efforts to debottleneck its production facilities to meet long-term
demand continue to prove  successful.  Such  debottlenecking  efforts  included,
among other things,  the addition of finishing  capacity in the German  chloride
process facility and equipment upgrades and enhancements in several locations to
allow for  reduced  downtime  for  maintenance  activities.  Kronos'  production
capacity  has  increased  by  approximately  30% over the past ten  years due to
debottlenecking  programs,  with  only  moderate  capital  expenditures.  Kronos
believes its annual  attainable  production  capacity for 2006 is  approximately
510,000 metric tons, with some additional  capacity  expected to be available in
2007 through its continued debottlenecking efforts.

Kronos  expects  its income  from  operations  in 2006 will  continue to be
somewhat lower than 2005.  Kronos'  expectations  as to the future  prospects of
Kronos and the TiO2 industry are based upon a number of factors  beyond  Kronos'
control,  including  worldwide growth of gross domestic product,  competition in
the  marketplace,  unexpected or  earlier-than-expected  capacity  additions and
technological advances. If actual developments differ from Kronos' expectations,
Kronos' results of operations could be unfavorably affected.

Kronos'  interest  expense  relates  principally  to Kronos  International,
Inc.'s ("KII") Senior Secured Notes. In April 2006, KII called all of its 8.875%
Senior  Secured  Notes  for  redemption  on May 11,  2006 at  104.437%  of their
aggregate  principal  amount of euro 375 million (an aggregate of $470.2 million
at March 31, 2006 exchange  rates).  Funds for such  redemption were provided by
KII's issuance of an aggregate of euro 400 million  principal amount of new 6.5%
Senior  Secured  Notes due April  2013,  issued on April 11,  2006 at 99.306% of
their principal amount. Kronos expects to recognize a $21 million pre-tax charge
in the second quarter related to the early  extinguishment  of the 8.875% Senior
Secured  Notes,  consisting  of the  call  premium  on  such  Notes  and the net
write-off of deferred financing costs and existing  unamortized  premium related
to such Notes.

General corporate items

Interest  expense.  Substantially  all of the interest  expense  relates to
CompX.  Interest  expense related to CompX declined in the first quarter of 2006
compared to 2005 due primarily to lower average levels of outstanding debt.

Insurance  recoveries.  NL has reached an agreement with a former insurance
carrier in which such carrier  would  reimburse NL for a portion of its past and
future lead pigment litigation defense costs.  During the first quarter of 2006,
NL received  approximately  $750,000 under such agreement.  The aggregate amount
that NL will  ultimately  recover from such carrier with respect to such defense
costs incurred by NL is not yet determinable.

Insurance   recoveries   in  the  first   quarter  of  2006  also   include
approximately $1.5 million in settlements NL received from certain of its former
insurance carriers.  These settlements,  as well as similar prior settlements NL
reached in the past few years, resolved court proceedings in which NL had sought
reimbursement  from carriers for legal defense costs and indemnity  coverage for
certain of NL's  environmental  remediation  expenditures.  No further  material
settlements  relating  to  litigation   concerning   environmental   remediation
coverages are expected.

While NL continues to seek additional insurance recoveries, there can be no
assurance  that NL will be  successful  in  obtaining  reimbursement  for either
defense  costs or  indemnity.  NL has not  considered  any  potential  insurance
recoveries in determining  related accruals for lead pigment litigation matters.
Any such additional  insurance recoveries would be recognized when their receipt
is deemed probable and the amount is determinable.

General  corporate  expense.  Net general  corporate  expenses in the first
quarter of 2006 were lower than the same period of 2005 due  primarily  to lower
environmental  remediation  and legal  expenses  of NL.  Net  general  corporate
expenses  in  calendar  2006 are  currently  expected  to be higher  than  2005,
primarily due to higher expected legal expenses of NL resulting from an increase
in litigation  and related  expenses.  However,  obligations  for  environmental
remediation  are  difficult to assess and estimate and no assurance can be given
that  actual  costs  will not exceed  accrued  amounts or that costs will not be
incurred  with respect to sites for which no estimate of liability can presently
be made. See Note 12 to the Consolidated Financial Statements.

Provision for income taxes

The principal  reasons for the difference  between the Company's  effective
income tax rate and the U.S. federal statutory income tax rates are explained in
Note 10 to the Consolidated Financial Statements.

Minority interest

See Note 9 to the Consolidated Financial Statements.

Discontinued operations.

See Note 13 to the Consolidated Financial Statements.

Accounting principles newly adopted in 2006.

See Note 14 to the Consolidated Financial Statements.

LIQUIDITY AND CAPITAL RESOURCES:

Consolidated cash flows

Summary

The  Company's  primary  source of liquidity on an ongoing  short-term  and
long-term basis is its cash flows from operating activities,  which is generally
used to (i) fund capital  expenditures,  (ii) repay any short-term  indebtedness
incurred  primarily  for  working  capital  purposes  and (iii)  provide for the
payment of  dividends.  In addition,  from  time-to-time  the Company will incur
indebtedness,  generally to (i) fund  short-term  working  capital  needs,  (ii)
refinance existing  indebtedness or (iii) fund major capital expenditures or the
acquisition of other assets outside the ordinary  course of business.  Also, the
Company  will from  time-to-time  sell  assets  outside the  ordinary  course of
business,  the  proceeds  of which  are  generally  used to (i)  repay  existing
indebtedness  (including  indebtedness which may have been collateralized by the
assets sold),  (ii) make investments in marketable and other  securities,  (iii)
fund major capital  expenditures  or the acquisition of other assets outside the
ordinary course of business or (iv) pay dividends.

Based  upon the  Company's  expectations  for the  industries  in which its
subsidiaries  and  affiliates  operate,  and  the  anticipated  demands  on  the
Company's  cash  resources  as  discussed  herein,  the Company  expects to have
sufficient  liquidity  to meet its  obligations  including  operations,  capital
expenditures,  debt  service and  current  dividend  policy.  To the extent that
actual  developments  differ  from the  Company's  expectations,  the  Company's
liquidity could be adversely affected.

Operating activities

Trends in cash flows from  operating  activities  (excluding  the impact of
significant  asset  dispositions and relative changes in assets and liabilities)
are generally  similar to trends in the  Company's  earnings.  However,  certain
items included in the  determination  of net income are non-cash,  and therefore
such  items have no impact on cash flows  from  operating  activities.  Non-cash
items  included in the  determination  of net income  include  depreciation  and
amortization expense and deferred income taxes.

Certain other items included in the determination of net income may have an
impact on cash flows from operating activities,  but the impact of such items on
cash  flows from  operating  activities  will  differ  from their  impact on net
income. For example, equity in earnings of affiliates will generally differ from
the amount of distributions received from such affiliates,  and equity in losses
of affiliates does not  necessarily  result in current cash outlays paid to such
affiliates.  The amount of periodic  defined  benefit  pension  plan expense and
periodic  OPEB  expense  depends  upon a number of  factors,  including  certain
actuarial assumptions,  and changes in such actuarial assumptions will result in
a change in the  reported  expense.  In  addition,  the amount of such  periodic
expense  generally  differs from the outflows of cash  required to currently pay
for such benefits.

Certain  other items  included in the  determination  of net income have no
impact on cash flows from  operating  activities,  but such items do impact cash
flows  from  investing  activities  (although  their  impact on such cash  flows
differs from their impact on net income). For example, realized gains and losses
from the disposal of long-lived  assets are included in the determination of net
income,  although the proceeds  from any such disposal are shown as part of cash
flows from investing activities.

Relative changes in assets and liabilities generally result from the timing
of production,  sales, purchases and income tax payments.  Such relative changes
can  significantly  impact the  comparability  of cash flow from operations from
period to period,  as the income  statement  impact of such items may occur in a
different  period from when the underlying  cash  transaction  occurs.  Relative
changes in accounts  receivable are affected by, among other things,  the timing
of sales and the  collection of the resulting  receivable.  Relative  changes in
inventories,  accounts  payable and accrued  liabilities  are affected by, among
other  things,  the timing of raw  material  purchases  and the payment for such
purchases  and the  relative  difference  between  production  volumes and sales
volumes.  Relative changes in accrued environmental costs are affected by, among
other things,  the period in which the  environmental  accrual is recognized and
the period in which the remediation expenditure is actually made.

Cash flows from  operating  activities  increased from $3.9 million used by
operating  activities  in the first three months of 2005 to $2.0 million of cash
provided by operating  activities  in the first three months of 2006.  This $5.9
million increase was due primarily to the net effects of (i) lower net income of
$8.0 million,  (ii) lower deferred  income taxes of $1.8 million,  (iii) a lower
amount of net cash used from  relative  changes  in the  Company's  inventories,
receivables,  payables and accruals of $1.2 million in the first three months of
2006 as compared to the first three months of 2005 (iv) lower equity in earnings
from  Kronos of $2.4  million  and (v) lower cash paid for income  taxes of $2.1
million.  Relative  changes in accounts  receivable are affected by, among other
things,  the timing of sales and the  collection of the  resulting  receivables.
Relative changes in inventories and accounts payable and accrued liabilities are
affected by, among other  things,  the timing of raw material  purchases and the
payment  for such  purchases  and the  relative  difference  between  production
volumes and sales volumes.  Relative changes in accrued  environmental costs are
affected  by,  among  other  things,  the  period  in which  recognition  of the
environmental  accrual is  recognized  and the  period in which the  remediation
expenditure is actually made.

Relative  changes in working  capital  assets  and  liabilities  can have a
significant effect on cash flows from operating activities. CompX's average days
sales outstanding related to its continuing operations increased from 40 days at
December 31, 2005 to 44 days at March 31, 2006,  due to the timing of collection
on the slightly higher accounts receivable balance at the end of March.  CompX's
average number of days in inventory related to its continuing  operations was 59
days at December 31, 2005 and 57 days at March 31, 2006. The decrease in days in
inventory is primarily due to lower raw materials inventory.

NL does not have complete access to the cash flows of its  subsidiaries and
affiliates, in part due to limitations contained in certain credit agreements as
well as the fact that certain of such  subsidiaries  and affiliates are not 100%
owned by NL. A detail of NL's consolidated cash flows from operating  activities
is presented in the table below. Eliminations consist of intercompany dividends,
which are paid by CompX to NL.

Three months ended
March 31,
----------------------
2005              2006
----              ----
(In millions)

Cash provided (used) by operating activities:

CompX                                                          $ 1.9             $ 4.0
NL Parent                                                       (3.4)               .2
Other                                                           (1.1)              (.9)
Eliminations                                                    (1.3)             (1.3)
-----             -----

$(3.9)            $ 2.0
=====             =====

Investing and financing activities

Substantially all of the Company's consolidated capital expenditures relate
to CompX.  During the first  quarter  of 2006,  (i) NL  purchased  approximately
26,500 shares of CompX common stock in market  transactions  for an aggregate of
$404,000,  (ii) CompX prepaid certain industrial revenue bonds, reducing debt by
$1.5 million and (iii) NL paid cash dividends of $6.1 million ($.125 per share).
Distributions   to  minority   interest  consist  of  CompX  dividends  paid  to
shareholders  other than NL. Other cash flows from financing  activities  relate
primarily  to  proceeds  from the  issuance  of NL and CompX  common  stock upon
exercise of stock options.

At March 31, 2006, there were no amounts  outstanding  under CompX's credit
facility  that matures in January  2009.  The Company does not expect it will be
required to use any of its cash flow from operating  activities generated during
2006 to repay indebtedness.

Provisions  contained in certain of the Company's and its subsidiaries' and
affiliates' credit agreements could result in the acceleration of the applicable
indebtedness  prior to its stated  maturity for reasons other than defaults from
failing to comply with typical financial covenants.  For example, certain credit
agreements allow the lender to accelerate the maturity of the indebtedness  upon
a change of control (as defined) of the borrower.  In addition,  certain  credit
agreements  could  result  in  the  acceleration  of  all  or a  portion  of the
indebtedness following a sale of assets outside the ordinary course of business,
which  provision was waived in connection with CompX's sale of its Thomas Regout
operations.

Off-balance sheet financing arrangements

Other than the operating leases discussed in the 2005 Annual Report, NL nor
any of its  subsidiaries  or  affiliates  are parties to any  off-balance  sheet
financing arrangements.

CompX

Certain of the CompX's  sales  generated  by its  non-U.S.  operations  are
denominated in U.S. dollars.  CompX periodically uses currency forward contracts
to manage a very nominal  portion of foreign  exchange rate risk associated with
receivables  denominated  in a  currency  other  than  the  holder's  functional
currency or similar  exchange rate risk associated with future sales.  CompX has
not entered  into these  contracts  for trading or  speculative  purposes in the
past,  nor does CompX  currently  anticipate  entering  into such  contracts for
trading  or  speculative  purposes  in the  future.  Derivatives  used to  hedge
forecasted transactions and specific cash flows associated with foreign currency
denominated  financial assets and liabilities  which meet the criteria for hedge
accounting  are  designated  as cash flow hedges.  Consequently,  the  effective
portion of gains and losses is  deferred  as a component  of  accumulated  other
comprehensive  income and is  recognized in earnings at the time the hedged item
affects  earnings.  Contracts that do not meet the criteria for hedge accounting
are  marked-to-market at each balance sheet date with any resulting gain or loss
recognized in income currently as part of net currency  transactions.  To manage
such exchange  rate risk,  at March 31, 2006,  CompX held a series of contracts,
which mature  through June 2006,  to exchange an aggregate of U.S.  $5.2 million
for an equivalent  amount of Canadian  dollars at an exchange rate of Cdn. $1.16
per U.S. dollar.  At March 31, 2006, the actual exchange rate was Cdn. $1.17 per
U.S. dollar. The estimated fair value of such foreign currency forward contracts
at March 31, 2006 is not material.

CompX periodically evaluates its liquidity  requirements,  alternative uses
of  capital,  capital  needs and  available  resources  in view of,  among other
things,  its capital  expenditure  requirements,  dividend  policy and estimated
future operating cash flows. As a result of this process,  CompX has in the past
and may in the future seek to raise additional capital, refinance or restructure
indebtedness,   issue  additional   securities,   modify  its  dividend  policy,
repurchase  shares of its common  stock or take a  combination  of such steps or
other steps to manage its liquidity and capital resources.  In the normal course
of business,  CompX may review  opportunities  for  acquisitions,  divestitures,
joint  ventures  or  other  business  combinations  in  the  component  products
industry.  In the event of any such transaction,  CompX may consider using cash,
issuing  additional equity securities or increasing the indebtedness of CompX or
its subsidiaries.

Kronos

At March 31, 2006,  Kronos had cash,  cash  equivalents and marketable debt
securities of $65.3 million,  including restricted balances of $3.6 million, and
Kronos had  approximately  $124 million  available for borrowing under its U.S.,
Canadian and European credit facilities. Based upon Kronos' expectations for the
TiO2  industry and  anticipated  demands on Kronos' cash  resources as discussed
herein,  Kronos  expects  to  have  sufficient  liquidity  to  meet  its  future
obligations including operations, capital expenditures, debt service and current
dividend  policy.  To the extent that actual  developments  differ from  Kronos'
expectations, Kronos' liquidity could be adversely affected.

At March 31, 2006,  Kronos'  outstanding  debt was  comprised of (i) $455.6
million  related to KII's  Senior  Secured  Notes and (ii)  approximately  $38.7
million of other indebtedness, principally $29.8 million related to Kronos' U.S.
bank credit facility which matures in September 2008 and $4.3 million related to
its Canadian bank credit  facility which matures in January 2009. In April 2006,
KII  called its  8.875%  Senior  Secured  Notes due 2009 for  redemption,  which
redemption will be funded by KII's new issuance of 6.5% Senior Secured Notes due
2013 issued in April 2006.

Based upon  Kronos'  expectations  for the TiO2  industry  and  anticipated
demand for Kronos' cash  resources as discussed  herein,  Kronos expects to have
sufficient short-term (defined as the twelve-month period ending March 31, 2007)
and  long-term  (defined as the five year period ending  December 31, 2010,  the
time period for which the Company generally does long-term  budgeting) liquidity
to meet its obligations including operations, capital expenditures, debt service
and  dividends.  To the extent that  actual  developments  differ  from  Kronos'
expectations, Kronos' liquidity could be adversely affected.

See Note 10 to the Consolidated Financial Statements for certain income tax
examinations  currently  underway with respect to certain of Kronos'  income tax
returns in  various  U.S.  and  non-U.S.  jurisdictions,  and see Note 12 to the
Consolidated Financial Statements with respect to certain legal proceedings with
respect to Kronos.

Certain of the Kronos'  sales  generated  by its  non-U.S.  operations  are
denominated in U.S. dollars. Kronos periodically uses currency forward contracts
to manage a very nominal  portion of foreign  exchange rate risk associated with
receivables  denominated  in a  currency  other  than  the  holder's  functional
currency or similar exchange rate risk associated with future sales.  Kronos has
not entered  into these  contracts  for trading or  speculative  purposes in the
past,  nor does Kronos  currently  anticipate  entering into such  contracts for
trading  or  speculative  purposes  in the  future.  Derivatives  used to  hedge
forecasted transactions and specific cash flows associated with foreign currency
denominated  financial assets and liabilities  which meet the criteria for hedge
accounting  are  designated  as cash flow hedges.  Consequently,  the  effective
portion of gains and losses is  deferred  as a component  of  accumulated  other
comprehensive  income and is  recognized in earnings at the time the hedged item
affects  earnings.  Contracts that do not meet the criteria for hedge accounting
are  marked-to-market at each balance sheet date with any resulting gain or loss
recognized in income currently as part of net currency  transactions.  To manage
such exchange  rate risk, at March 31, 2006,  Kronos held a series of contracts,
with  expiration  dates  ranging  from April to September  2006,  to exchange an
aggregate of U.S. $25.5 million for an equivalent  amount of Canadian dollars at
exchange rates ranging from Cdn. $1.16 to Cdn. $1.17 per U.S.  dollar.  At March
31, 2006, the actual exchange rate was Cdn. $1.17 per U.S. dollar. The estimated
fair value of such  foreign  currency  forward  contracts  at March 31,  2006 is
insignificant.

KII's  assets   consist   primarily  of   investments   in  its   operating
subsidiaries, and its ability to service its parent level obligations, including
the  Senior  Secured  Notes,  depends  in large  part upon the  distribution  of
earnings  of its  subsidiaries,  whether in the form of  dividends,  advances or
payments  on account  of  intercompany  obligation,  or  otherwise.  None of its
subsidiaries   have  guaranteed  the  Senior  Secured  Notes,   although  Kronos
International has pledged 65% of the common stock or other ownership interest of
certain of its first-tier  operating  subsidiaries  as collateral of such Senior
Secured Notes.

Kronos periodically evaluates its liquidity requirements,  alternative uses
of capital,  capital needs and availability of resources in view of, among other
things,  its  dividend  policy,   its  debt  service  and  capital   expenditure
requirements  and estimated  future  operating  cash flows.  As a result of this
process, Kronos has in the past and may in the future seek to reduce, refinance,
repurchase or restructure  indebtedness,  raise additional  capital,  repurchase
shares of its common stock,  modify its dividend policy,  restructure  ownership
interests, sell interests in subsidiaries or other assets, or take a combination
of such steps or other steps to manage its liquidity and capital  resources.  In
the normal  course of its  business,  Kronos may  review  opportunities  for the
acquisition,  divestiture,  joint venture or other business  combinations in the
chemicals or other  industries,  as well as the acquisition of interests in, and
loans to, related  entities.  In the event of any such  transaction,  Kronos may
consider  using  available  cash,   issuing  equity   securities  or  increasing
indebtedness  to the  extent  permitted  by  the  agreements  governing  Kronos'
existing debt.

Kronos has  substantial  operations  located  outside the United States for
which the functional  currency is not the U.S. dollar. As a result, the reported
amounts of Kronos' assets and  liabilities  related to its non-U.S.  operations,
and therefore Kronos' net assets,  will fluctuate based upon changes in currency
exchange rates.

NL Industries

At March 31, 2006, NL (exclusive of CompX) had cash,  cash  equivalents and
marketable debt securities of $52.8 million,  including  restricted  balances of
$13.2 million.

See Note 10 to the Consolidated Financial Statements for certain income tax
examinations  currently  underway  with  respect to  certain of NL's  income tax
returns,  and see Note 12 to the Consolidated  Financial Statements and Part II,
Item 1,  "Legal  Proceedings"  with  respect to certain  legal  proceedings  and
environmental matters with respect to NL.

In  addition  to  those  legal  proceedings  described  in  Note  12 to the
Consolidated  Financial  Statements,   various  legislation  and  administrative
regulations  have,  from time to time,  been  proposed  that seek to (i)  impose
various  obligations  on present and former  manufacturers  of lead  pigment and
lead-based  paint with respect to asserted health  concerns  associated with the
use of such products and (ii)  effectively  overturn court decisions in which NL
and other pigment manufacturers have been successful.  Examples of such proposed
legislation  include bills which would permit civil liability for damages on the
basis of market  share,  rather  than  requiring  plaintiffs  to prove  that the
defendant's  product  caused the alleged  damage,  and bills which would  revive
actions  barred  by  the  statute  of  limitations.   While  no  legislation  or
regulations  have been  enacted  to date that are  expected  to have a  material
adverse effect on NL's consolidated financial position, results of operations or
liquidity, enactment of such legislation could have such an effect.

NL periodically evaluates its liquidity  requirements,  alternative uses of
capital,  capital  needs and  availability  of resources in view of, among other
things, its dividend policy and capital  expenditure  requirements and estimated
future operating cash flows. As a result of this process, NL has in the past and
may  in  the  future  seek  to  reduce,  refinance,  repurchase  or  restructure
indebtedness,  raise additional capital,  repurchase shares of its common stock,
modify its dividend policy,  restructure ownership interests,  sell interests in
subsidiaries or other assets, or take a combination of such steps or other steps
to manage its  liquidity  and  capital  resources.  In the normal  course of its
business,  NL may review opportunities for the acquisition,  divestiture,  joint
venture or other business combinations in the chemicals or other industries,  as
well as the acquisition of interests in, and loans to, related entities.

Because NL's operations are conducted  primarily  through its  subsidiaries
and  affiliates,  NL's  long-term  ability  to meet  its  parent  company  level
corporate  obligations is dependent in large measure on the receipt of dividends
or other  distributions  from its  subsidiaries  and  affiliates.  In the fourth
quarter of 2004,  CompX reinstated its regular  quarterly  dividend at the $.125
per share rate. At that rate, and based on the 10.6 million shares of CompX held
directly or  indirectly  by NL at March 31,  2006,  NL would  receive  aggregate
annual dividends from CompX of $5.3 million.  In February 2004, Kronos announced
it would pay its first regular  quarterly  cash  dividend of $.25 per share.  At
that rate,  and based on the 17.5  million  shares of Kronos held by NL at March
31, 2006,  NL would  receive  aggregate  annual  dividends  from Kronos of $17.5
million.  If NL's  subsidiaries  would  become  unable to make  sufficient  cash
dividends or other  distributions to it, NL's ability to service its liabilities
and to pay  dividends  on its  common  stock  could be  adversely  affected.  In
addition,  a significant  portion of NL's assets consists of ownership interests
in its subsidiaries and affiliates. If NL were required to liquidate any of such
securities  in order to  generate  funds to satisfy its  liabilities,  NL may be
required  to sell  such  securities  at a time or times at which it would not be
able to realize what it believes to be the actual value of such assets.

The Company routinely  compares its liquidity  requirements and alternative
uses of capital against the estimated  future cash flows to be received from its
subsidiaries,  and the estimated sales value of those units. As a result of this
process,  the  Company  has in the  past  and may in the  future  seek to  raise
additional   capital,   refinance  or   restructure   indebtedness,   repurchase
indebtedness in the market or otherwise,  modify its dividend policies, consider
the sale of interests in subsidiaries,  affiliates,  business units,  marketable
securities or other assets,  or take a combination of such steps or other steps,
to increase  liquidity,  reduce  indebtedness and fund future  activities.  Such
activities have in the past and may in the future involve related companies.

The  Company  and  related  entities  routinely  evaluate  acquisitions  of
interests in, or combinations  with,  companies,  including  related  companies,
perceived by management to be undervalued in the  marketplace.  These  companies
may or may  not be  engaged  in  businesses  related  to the  Company's  current
businesses.  The Company intends to consider such acquisition  activities in the
future and, in connection with this activity,  may consider  issuing  additional
equity   securities  and  increasing  the  indebtedness  of  the  Company,   its
subsidiaries and related  companies.  From time to time, the Company and related
entities  also evaluate the  restructuring  of ownership  interests  among their
respective subsidiaries and related companies.

Non-GAAP financial measures

In an effort to provide investors with additional information regarding the
Company's results of operations as determined by GAAP, the Company has disclosed
certain  non-GAAP   information  which  the  Company  believes  provides  useful
information to investors.

o    The Company  discloses  percentage  changes in Kronos' average TiO2 selling
prices in  billing  currencies,  which  excludes  the  effects  of  foreign
currency  translation.  The Company believes  disclosure of such percentage
changes  allows  investors to analyze  such  changes  without the impact of
changes  in  foreign   currency   exchange  rates,   thereby   facilitating
period-to-period  comparisons  of the  relative  changes  in  average  TiO2
selling prices in the actual various billing  currencies.  Generally,  when
the U.S. dollar either strengthens or weakens against other currencies, the
percentage change in average TiO2 selling prices in billing currencies will
be higher or lower,  respectively,  than such  percentage  changes would be
using actual exchange rates prevailing during the respective periods.

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURE ABOUT MARKET RISK

Reference is made to the 2005 Annual  Report for a discussion of the market
risks associated with changes in foreign currency exchange rates, interest rates
and security prices that affect the Company. There have been no material changes
in such market  risks since the Company  filed the 2005 Annual  Report.  

ITEM 4.
CONTROLS AND PROCEDURES

Evaluation of Disclosure  Controls and Procedures.  The Company maintains a
system of disclosure controls and procedures.  The term "disclosure controls and
procedures,"  as defined by  regulations  of the SEC,  means  controls and other
procedures that are designed to ensure that information required to be disclosed
in the reports that the Company files or submits to the SEC under the Securities
Exchange Act of 1934, as amended (the "Act"), is recorded, processed, summarized
and  reported,  within the time periods  specified in the SEC's rules and forms.
Disclosure  controls and procedures include,  without  limitation,  controls and
procedures  designed to ensure that information  required to be disclosed by the
Company  in the  reports  that it files or  submits  to the SEC under the Act is
accumulated  and  communicated  to  the  Company's  management,   including  its
principal  executive  officer and its principal  financial  officer,  or persons
performing  similar  functions,  as appropriate to allow timely  decisions to be
made regarding  required  disclosure.  Each of Harold C. Simmons,  the Company's
Chief Executive Officer, and Gregory M. Swalwell,  the Company's Vice President,
Finance and Chief  Financial  Officer,  have evaluated the Company's  disclosure
controls and procedures as of March 31, 2006. Based upon their evaluation, these
executive  officers have  concluded that the Company's  disclosure  controls and
procedures are effective as of March 31, 2006.

Internal  Control Over  Financial  Reporting.  The Company  also  maintains
internal  control over  financial  reporting.  The term  "internal  control over
financial  reporting,"  as defined by  regulations  of the SEC,  means a process
designed by, or under the supervision of, the Company's  principal executive and
principal  financial  officers,  or persons performing  similar  functions,  and
effected by the Company's board of directors, management and other personnel, to
provide reasonable  assurance  regarding the reliability of financial  reporting
and the preparation of financial  statements for external purposes in accordance
with GAAP, and includes those policies and procedures that:

o    Pertain to the maintenance of records that in reasonable  detail accurately
and fairly reflect the  transactions  and dispositions of the assets of the
Company,
o    Provide reasonable assurance that transactions are recorded as necessary to
permit  preparation  of financial  statements in accordance  with GAAP, and
that  receipts  and  expenditures  of the  Company  are being  made only in
accordance with  authorizations of management and directors of the Company,
and
o    Provide reasonable assurance regarding prevention or timely detection of an
unauthorized  acquisition,  use or disposition of the Company's assets that
could  have a  material  effect  on the  Company's  Consolidated  Financial
Statements.

As permitted by the SEC, the Company's  assessment of internal control over
financial  reporting  excludes (i) internal control over financial  reporting of
its equity method  investees and (ii) internal  control over the  preparation of
the Company's financial statement schedules required by Article 12 of Regulation
S-X.  However,  the  Company's  assessment  of internal  control over  financial
reporting with respect to the Company's  equity method investees did include the
Company's  controls  over the  recording  of amounts  related  to the  Company's
investments   that  are  recorded  in  the  Company's   consolidated   financial
statements,  including controls over the selection of accounting methods for the
Company's investments,  the recognition of equity method earnings and losses and
the determination,  valuation and recording of the Company's  investment account
balances.

Changes in Internal  Control Over  Financial  Reporting.  There has been no
change to the Company's  internal  control over financial  reporting  during the
quarter  ended March 31, 2006 that has  materially  affected,  or is  reasonably
likely to materially  affect,  the  Company's  internal  control over  financial
reporting.

PART II. OTHER INFORMATION

Item 1. Legal Proceedings

Reference is made to Note 12 to the Consolidated  Financial  Statements and
to the 2005 Annual Report for descriptions of certain previously  reported legal
proceedings.

State of Rhode  Island v. Lead  Industries  Association,  et al.  (Superior
Court of Rhode Island, No. 99-5226). In April 2006, NL filed a post-trial motion
to dismiss,  motion for new trial and motion for  judgment  notwithstanding  the
verdict.

Smith,  et al. v. Lead  Industries  Association,  et al. (Circuit Court for
Baltimore City, Maryland,  Case No.  24-C-99-004490).  In March 2006, defendants
filed a conditional  cross-appeal,  asserting that there is no final judgment to
be reviewed because the trial court's severance was improper.

County of Santa Clara v. Atlantic Richfield Company, et al. (Superior Court
of the State of California,  County of Santa Clara, Case No. CV788657). In March
2006,  defendants  filed a petition for rehearing with the appellate  court.  In
April 2006,  the  defendants  filed a petition  for review  with the  California
Supreme Court; however this petition was denied.

City of Milwaukee v. NL Industries,  Inc. and Mautz Paint  (Circuit  Court,
Civil Division,  Milwaukee County,  Wisconsin,  Case No.  01CV003066).  In March
2006, the court denied the defendants' motion to dismiss and set a trial date of
January 2007.

Hess, et. al. v. NL Industries,  Inc., et al. (Missouri  Circuit Court 22nd
Judicial  Circuit,  St.  Louis  City,  Cause No.  052-11799).  NL has denied all
allegations of liability. In April 2006, NL removed the case to Federal Court.

In April 2006, NL and the U.S. EPA entered into an administrative  order on
consent to perform an  additional  removal  action with respect to ponds located
within a residential area at the site of a formerly owned lead smelting facility
located in Collinsville, Illinois.

Brown et. al. v. NL Industries,  Inc. et. al.  (Circuit Court Wayne County,
Michigan,  Case No.  06-602096  CZ).  In February  2006,  NL removed the case to
federal court.

Item 1A. Risk  Factors.  Reference is made to the 2005 Annual  Report for a
discussion of risk factors related to the Company's businesses.  There have been
no material changes in such risk factors since the Company filed the 2005 Annual
Report.

Item 6.  Exhibits

31.1 -  Certification

31.2 -  Certification

32.1 -  Certification

The Company  has  retained a signed  original of any of the above  exhibits
that  contains  signatures,  and the Company  will  provide  such exhibit to the
Commission or its staff upon request.  NL will also furnish,  without charge,  a
copy of its Code of Business Conduct and Ethics, its Audit Committee Charter and
its Corporate Governance  Guidelines,  each as adopted by the Company's board of
directors,  upon request.  Such requests  should be directed to the attention of
NL's Corporate  Secretary at NL's corporate offices located at 5430 LBJ Freeway,
Suite 1700, Dallas, Texas 75240.

SIGNATURES

Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.

NL INDUSTRIES, INC.      
------------------------
(Registrant)

Date   May 5, 2006            By /s/ Gregory M. Swalwell       
-------------              -------------------------------------
Gregory M. Swalwell
Vice President, Finance and 
Chief Financial Officer 
(Principal Financial Officer)

Date   May 5 , 2006           By /s/ James W. Brown             
-------------              -------------------------------------
James W. Brown
Vice President and Controller
(Principal Accounting Officer)

CERTIFICATION

I,  Harold C.  Simmons, certify that:

1)   I have reviewed this quarterly report on Form 10-Q of NL Industries, Inc.;

2)   Based on my knowledge, this report does not contain any untrue statement of
a material  fact or omit to state a  material  fact  necessary  to make the
statements made, in light of the circumstances  under which such statements
were made,  not  misleading  with  respect  to the  period  covered by this
report;

3)   Based on my  knowledge,  the  financial  statements,  and  other  financial
information  included  in  this  report,  fairly  present  in all  material
respects the financial  condition,  results of operations and cash flows of
the registrant as of, and for, the periods presented in this report;

4)   The  registrant's  other  certifying  officer  and  I are  responsible  for
establishing and maintaining disclosure controls and procedures (as defined
in Exchange Act Rules  13a-15(e) and 15d-15(e))  and internal  control over
financial  reporting  (as  defined  in  Exchange  Act Rules  13a-15(f)  and
15d-15(f)) for the registrant and we have:

a)   Designed  such  disclosure  controls  and  procedures,  or caused such
disclosure   controls  and   procedures  to  be  designed   under  our
supervision,  to ensure  that  material  information  relating  to the
registrant,  including its consolidated subsidiaries, is made known to
us by others within those entities,  particularly during the period in
which this report is being prepared;

b)   Designed such internal  control over  financial  reporting,  or caused
such internal  control over  financial  reporting to be designed under
our  supervision,   to  provide  reasonable  assurance  regarding  the
reliability  of financial  reporting and the  preparation of financial
statements for external purposes in accordance with generally accepted
accounting principles;

c)   Evaluated the  effectiveness of the registrant's  disclosure  controls
and procedures and presented in this report our conclusions  about the
effectiveness of the disclosure controls and procedures, as of the end
of the period covered by this report based on such evaluation; and

d)   Disclosed  in this  report  any  change in the  registrant's  internal
control over financial reporting that occurred during the registrant's
most recent fiscal quarter (the registrant's  fourth fiscal quarter in
the case of an annual  report)  that has  materially  affected,  or is
reasonably  likely to materially  affect,  the  registrant's  internal
control over financial reporting; and

5)   The registrant's  other certifying  officer and I have disclosed,  based on
our most recent evaluation of internal control over financial reporting, to
the registrant's  auditors and the audit committee of registrant's board of
directors (or persons performing the equivalent function):

a)   All significant  deficiencies and material weaknesses in the design or
operation  of internal  control  over  financial  reporting  which are
reasonably  likely to  adversely  affect the  registrant's  ability to
record, process, summarize and report financial information; and

b)   Any fraud, whether or not material,  that involves management or other
employees who have a  significant  role in the  registrant's  internal
control over financial reporting.

Date:  May 5, 2006

/s/  Harold C. Simmons                      
------------------------------
Harold C. Simmons
Chief Executive Officer

Exhibit 31.2
CERTIFICATION

I, Gregory M. Swalwell, certify that:

1)   I have reviewed this quarterly report on Form 10-Q of NL Industries, Inc.;

2)   Based on my knowledge, this report does not contain any untrue statement of
a material  fact or omit to state a  material  fact  necessary  to make the
statements made, in light of the circumstances  under which such statements
were made,  not  misleading  with  respect  to the  period  covered by this
report;

3)   Based on my  knowledge,  the  financial  statements,  and  other  financial
information  included  in  this  report,  fairly  present  in all  material
respects the financial  condition,  results of operations and cash flows of
the registrant as of, and for, the periods presented in this report;

4)   The  registrant's  other  certifying  officer  and  I are  responsible  for
establishing and maintaining disclosure controls and procedures (as defined
in Exchange Act Rules  13a-15(e) and 15d-15(e))  and internal  control over
financial  reporting  (as  defined  in  Exchange  Act Rules  13a-15(f)  and
15d-15(f)) for the registrant and we have:

a)   Designed  such  disclosure  controls  and  procedures,  or caused such
disclosure   controls  and   procedures  to  be  designed   under  our
supervision,  to ensure  that  material  information  relating  to the
registrant,  including its consolidated subsidiaries, is made known to
us by others within those entities,  particularly during the period in
which this report is being prepared;

b)   Designed such internal  control over  financial  reporting,  or caused
such internal  control over  financial  reporting to be designed under
our  supervision,   to  provide  reasonable  assurance  regarding  the
reliability  of financial  reporting and the  preparation of financial
statements for external purposes in accordance with generally accepted
accounting principles;

c)   Evaluated the  effectiveness of the registrant's  disclosure  controls
and procedures and presented in this report our conclusions  about the
effectiveness of the disclosure controls and procedures, as of the end
of the period covered by this report based on such evaluation; and

d)   Disclosed  in this  report  any  change in the  registrant's  internal
control over financial reporting that occurred during the registrant's
most recent fiscal quarter (the registrant's  fourth fiscal quarter in
the case of an annual  report)  that has  materially  affected,  or is
reasonably  likely to materially  affect,  the  registrant's  internal
control over financial reporting; and

5)   The registrant's  other certifying  officer and I have disclosed,  based on
our most recent evaluation of internal control over financial reporting, to
the registrant's  auditors and the audit committee of registrant's board of
directors (or persons performing the equivalent function):

a)   All significant  deficiencies and material weaknesses in the design or
operation  of internal  control  over  financial  reporting  which are
reasonably  likely to  adversely  affect the  registrant's  ability to
record, process, summarize and report financial information; and

b)   Any fraud, whether or not material,  that involves management or other
employees who have a  significant  role in the  registrant's  internal
control over financial reporting.

Date:  May 5, 2006

/s/  Gregory M. Swalwell                    
---------------------------------
Gregory M. Swalwell
Chief Financial Officer

Exhibit 32.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of NL Industries,  Inc. (the Company) on
Form 10-Q for the quarter ended March 31, 2006 as filed with the  Securities and
Exchange Commission on the date hereof (the Report), I, Harold C. Simmons, Chief
Executive  Officer of the Company,  and I, Gregory M. Swalwell,  Chief Financial
Officer of the Company,  certify, pursuant to 18 U.S.C. section 1350, as adopted
pursuant to section 906 of the Sarbanes-Oxley Act of 2002, that:

(1)  The Report fully complies with the  requirements  of section 13(a) or 15(d)
of the Securities Exchange Act of 1934; and

(2)  The information  contained in the Report fairly  presents,  in all material
respects, the financial condition and results of operations of the Company.

/s/ Harold C. Simmons
------------------------------
Harold C. Simmons
Chief Executive Officer

/s/ Gregory M. Swalwell
------------------------------
Gregory M. Swalwell
Chief Financial Officer

May 5, 2006

Note: The certification  the registrant  furnishes in this exhibit is not deemed
"filed" for purposes of Section 18 of the  Securities  Exchange Act of 1934,  as
amended,  or otherwise subject to the liabilities of that Section.  Registration
Statements or other documents filed with the Securities and Exchange  Commission
shall not incorporate this exhibit by reference,  except as otherwise  expressly
stated in such filing.