Exhibit 99
Additional Information

     Valhi, Inc., Harold C. Simmons,  TIMET Finance Management Company ("TFMC"),
and Harold C. Simmons'  spouse are the direct  holders of  approximately  83.2%,
1.1%,  0.5% and  0.5%,  respectively,  of the  outstanding  common  stock of the
issuer, NL Industries, Inc. ("NL"). Titanium Metals Corporation ("TIMET") is the
sole stockholder of TFMC.

     Tremont LLC  ("Tremont"),  Harold C. Simmons'  spouse,  The Combined Master
Retirement  Trust  (the  "CMRT"),  Valhi and  Harold C.  Simmons  are the direct
holders of approximately  31.3%,  11.8%, 9.5%, 3.9% and 3.1% of the outstanding
shares of TIMET common stock. The ownership of Ms. Simmons  includes  21,333,333
shares of TIMET common  stock that she has the right to acquire upon  conversion
of 1,600,000 shares of the TIMET's 6 3/4% Series A Convertible  Preferred Stock,
par value $0.01 per share (the  "Series A Preferred  Stock"),  that she directly
owns. The ownership of Valhi includes 196,000 shares of the TIMET's common stock
that Valhi has the right to acquire upon conversion of 14,700 shares of Series A
Preferred  Stock that Valhi  directly  holds.  The  percentage  ownership of the
TIMET's common stock held by Ms.  Simmons and Valhi assumes the full  conversion
of  only  the  shares  of  Series  A  Preferred  Stock  owned  by her or  Valhi,
respectively.

     Valhi is the sole member of Tremont.  Valhi Holding  Company  ("VHC"),  the
Harold  Simmons  Foundation,  Inc.  (the  "Foundation"),  the  Contran  Deferred
Compensation  Trust No. 2 (the "CDCT No. 2") and the CMRT are the direct holders
of 92.1%, 0.9%, 0.4% and 0.1%, respectively, of the common stock of Valhi. Valhi
Group,  Inc.  ("VGI"),  National  City  Lines,  Inc.  ("National")  and  Contran
Corporation  ("Contran")  are the  direct  holders  of  87.4%,  10.3%  and 2.3%,
respectively,  of the  outstanding  common  stock of VHC.  National,  NOA,  Inc.
("NOA") and Dixie Holding  Company  ("Dixie  Holding") are the direct holders of
approximately  73.3%, 11.4% and 15.3%,  respectively,  of the outstanding common
stock of VGI. Contran and NOA are the direct holders of approximately  85.7% and
14.3%,  respectively,  of the outstanding common stock of National.  Contran and
Southwest Louisiana Land Company,  Inc.  ("Southwest") are the direct holders of
approximately 49.9% and 50.1%, respectively,  of the outstanding common stock of
NOA.  Dixie Rice  Agricultural  Corporation,  Inc.  ("Dixie Rice") is the direct
holder of 100% of the outstanding common stock of Dixie Holding.  Contran is the
holder of 100% of the  outstanding  common stock of Dixie Rice.  Contran is also
the holder of approximately 88.9% of the outstanding common stock of Southwest.

     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 (the "Trusts"),  of which Mr. Simmons is the sole trustee, or is held by
Mr. Simmons or persons or entities  related to Mr.  Simmons.  As sole trustee of
the Trusts,  Mr. Simmons has the power to vote and direct the disposition of the
shares of Contran  stock held by the Trusts.  Mr.  Simmons,  however,  disclaims
beneficial ownership of any shares of Contran stock that the Trusts hold.

     Harold C. Simmons is the chairman of the board and chief executive  officer
of the issuer and the  chairman of the board of each of Tremont,  TIMET,  Valhi,
VHC, VGI, National, NOA, Dixie Holding, Dixie Rice, Southwest and Contran.

     The Foundation  directly holds  approximately 0.9% of the outstanding Valhi
common stock. The Foundation is a tax-exempt foundation organized for charitable
purposes.  Harold C.  Simmons is the  chairman of the board and chief  executive
officer of the Foundation and may be deemed to control the Foundation.

     The CDCT No. 2 directly holds  approximately  0.4% of the outstanding Valhi
common stock. U.S. Bank National  Association  serves as the trustee of the CDCT
No. 2. Contran  established  the CDCT No. 2 as an  irrevocable  "rabbi trust" to
assist Contran in meeting certain deferred compensation obligations that it owed
to Harold C. Simmons.  If the CDCT No. 2 assets are insufficient to satisfy such
obligations,  Contran is obligated to satisfy the balance of such obligations as
they come due.  Pursuant to the terms of the CDCT No. 2, Contran (i) retains the
power to vote the shares of Valhi common stock held  directly by the CDCT No. 2;
(ii)  retains  dispositive  power  over such  shares and (iii) may be deemed the
indirect beneficial owner of such shares.

     The CMRT directly holds  approximately  9.5% of the outstanding  shares of
TIMET common  stock and 0.1% of the  outstanding  shares of Valhi common  stock.
Contran  sponsors the CMRT to permit the collective  investment by master trusts
that maintain the assets of certain  employee  benefit plans Contran and related
companies adopt.  Harold C. Simmons is the sole trustee of the CMRT and a member
of the trust  investment  committee for the CMRT.  Contran's  board of directors
selects the trustee and members of the trust investment  committee for the CMRT.
Mr. Simmons is a participant  in one or more of the employee  benefit plans that
invest through the CMRT. He disclaims beneficial ownership of any shares held by
the CMRT, except to the extent of his individual vested beneficial interest,  if
any, in the assets held by the CMRT.

     By virtue of the  holding  of the  offices,  the  stock  ownership  and his
service as trustee,  all as described  above,  (a) Mr.  Simmons may be deemed to
control the  entities  described  above and (b) Mr.  Simmons and certain of such
entities may be deemed to possess indirect beneficial  ownership of shares of NL
common stock that Valhi and TFMC hold directly.  However,  Mr. Simmons disclaims
beneficial  ownership  of the  shares of NL  common  stock  beneficially  owned,
directly or indirectly, by any of such entities.

     NL and a  subsidiary  of NL directly  own  3,522,967  shares and  1,186,200
shares,  respectively,  of Valhi common stock.  Pursuant to Delaware law,  Valhi
treats the shares of Valhi  common  stock that NL and the  subsidiary  of NL own
directly  as treasury  stock for voting  purposes  and for the  purposes of this
statement are not deemed outstanding.

     Annette C.  Simmons is the wife of Harold C.  Simmons  and direct  owner of
256,575 of the issuer's common stock, 1,600,000 shares of the Series A Preferred
Stock, 128,600  shares of TIMET common  stock and 43,400  shares of Valhi common
stock. Mr. Simmons may be deemed to share indirect beneficial  ownership of such
securities.  Mr. Simmons disclaims  beneficial  ownership of all securities that
his spouse holds directly.

     Mr. Harold C. Simmons is the direct owner of 556,300 shares of the issuer's
common stock (including options exerciseable for 2,000 shares), 4,992,900 shares
of TIMET common stock and 3,383 shares of Valhi common stock.

     A trust of which Harold C. Simmons and his spouse are  co-trustees  and the
beneficiaries are the grandchildren of his spouse is the direct holder of 36,500
shares of Valhi common stock. Mr. Simmons,  as co-trustee of this trust, has the
power to vote and direct the disposition of the shares of Valhi common stock the
trust holds. Mr. Simmons disclaims  beneficial  ownership of any shares of Valhi
common stock that this trust holds.