1. Name and Address of Reporting Person Gum, Mary 199 Benson Road Middlebury, CT 06749 USA 2. Issuer Name and Ticker or Trading Symbol Crompton Corporation 3. IRS or Social Security Number of Reporting Person (Voluntary) 4. Statement for Month/Day/Year 01/21/2003 5. If Amendment, Date of Original (Month/Day/Year) 6. Relationship of Reporting Person(s) to Issuer (Check all applicable) ( ) Director ( ) 10% Owner (X) Officer (give title below) ( ) Other (specify below) Executive V.P. - OSI 7. Individual or Joint/Group Filing (Check Applicable Line) (X) Form filed by One Reporting Person ( ) Form filed by More than One Reporting Person TABLE I -- Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned +------------------------------+----------+----------+---------+--------------------------+--------------+-----------+------------+ |1. Title of Security |2. Trans- |2A.Execu- |3. Trans-|4. Securities Acquired (A)|5. Amount of |6. Owner- |7. Nature | | | action | action | action| or Disposed of (D) |Securities | ship | of In- | | | Date | Date | Code | |Beneficially | Form: | direct | | | | | | |Owned | Direct | Bene- | | | (Month/ | (Month/ | | |Following | (D) or | ficial | | | Day/ | Day/ +-----+---+-----------+---+----------+Reported | Indirect| Owner- | | | Year) | Year) |Code |V |Amount |A/D|Price |Transaction(s)| (I) | ship | +------------------------------+----------+----------+-----+---+-----------+---+----------+--------------+-----------+------------+ Common Stock 34340 D TABLE II -- Derivative Securities Acquired, Disposed of, or Beneficially Owned +----------+--------+-------+-------+---------+-----------+---------------------+----------------+----------+-------+-------+------+ |1. |2. |3. |3A. |4. |5. |6. |7. |8. |9. |10. |11. | | | | | | | | | | |Number |Owner- | | | | | | | | | | | |of |ship | | | | | | | | | | | |Deriv- |Form of| | | | | | | | | |Title and Amount| |ative |Deriv- | | | | | | | | | |of Underlying | |Secur- |ative |Nature| | |Conver- |Trans- |Execu- | |Number of | |Securities | |ities |Secur- |of | | |sion or |action |tion | |Derivative |Date Exercisable +-------+--------+ |Benefi-|ity: |In- | | |Exercise|Date |Date | |Securities |and Expiration Date | |Amount | |cially |Direct |direct| | |Price of| | |Transac- |Acquired(A)|(Month/Day/Year) | |or | |Owned |(D) or |Bene- | |Title of |Deriv- |(Month/|(Month/|tion Code|Disposed(D)+----------+----------+ |Number |Price of | |In- |ficial| |Derivative|ative | Day/ | Day/ +------+--+-----+-----+Date Exer-|Expira- | |of |Derivative| |direct |Owner-| |Security |Security|Year) |Year) |Code |V |(A) |(D) |cisable |tion Date |Title |Shares |Security | |(I) |ship | +----------+--------+-------+-------+------+--+-----+-----+----------+----------+-------+--------+----------+-------+-------+------+ NQ Stock $6.38 01/21/2 A43654 01/21/2004 02/20/2013 Common 43654 $0.0000 43654 D Option 003 Stock (Right to Buy) NQ Stock $7.25 11/21/2012 Common 21207 D Option Stock (Right to Buy) NQ Stock $7.92 11/22/2011 Common 47374 D Option Stock (Right to Buy) NQ Stock $8.1562 11/30/2010 Common 75000 D Option Stock (Right to Buy) NQ Stock $8.343 11/19/2009 Common 164045 D Option Stock (Right to Buy) ISO Stock $6.38 01/21/2 A 31346 01/21/2005 01/21/2013 Common 31346 $0.0000 31346 D Option 003 Stock (Right to Buy) ISO Stock $7.25 10/22/2012 Common 13793 D Option Stock (Right to Buy) ISO Stock $7.92 10/23/2011 Common 12626 D Option Stock (Right to Buy) ISO Stock $8.3437 10/19/2009 Common 35955 D Option Stock (Right to Buy) Explanation of Responses: SIGNATURE OF REPORTING PERSON /s/ Mary Gum DATE 01/23/2003 Options will vest as follows: 25,000 on 1/21/2004, 9,327 on 1/21/2005 and 9,327 on 1/21/2006. Options will vest as follows: 15,673 on 1/21/2005 and 15,673 on 1/21/2006.