Chemplast Sanmar Ltd (formerly knwon as Chemicals & Plastics India (CPIL)), incorporated in 1962 was promoted as Urethanes India by Chemplast, the flagship of the Sanmar group, Tamilnadu. It became a fully-owned subsidiary of Chemplast in 1991 when the name was changed to the present one.

The company created and deployed a 2500 tpa thermoplastic polyurethane plant in Tamilnadu in technical collaboration with BF Goodrich Company, US. It manufactures caustic soda, chlorine, chlorinated solvents, PVC, refrigerant gases and industrial alcohol.

In 1991-92, the capacity of PVC was enhanced to 48,000 tpa, making it the third largest manufacturer of PVC resin in the country. The company formed Peroxides India in collaboration with Atochem, US, for a wide variety of polymerisation initiators; and Drechem Speciality Chemicals, in technical collaboration with Dragoco, Germany, to manufacture aromatic chemicals.

The PVC capacity is being enhanced from 48,000 tpa to 60,000 tpa and that of chloromethanes is being enhanced to 25,000 tpa. In 1995-96, Metkem Silicon, a subsidiary of the company manufacturing poly and mono crystalline silicon was merged with the holding company. During the same period, the thermoplastics polyuerthane division of the company was spun-off into a joint venture with Bayer, Germany. It also has broadened its footprint operations into into a joint venture with Cabot Corporation, US, for the manufacture of fumed silica as a springboard.

The company is in advanced stage of discussing raw material tie-ups for its proposed shore-based PVC project. As a measure of conservation of power, the company is replacing shell and tube acid cooler and condensers with plate heat exchangers in the Chlor-alkali process.

The company has taken on hand a backward integration captive project for setting up an oxychlorination with the capital outlay of over Rs 60 crores. This will help the company to improve captive feedstock (EDC) capacity, leading to lower dependence on imported feedstock.

During 2000-01, the company brought on stream an oxychlorination plant which would increase captive production of EDC and reduce dependence on imports and also significantly reduce the environmental impact of its operations.

Subject to necessary approvals the company planned to amalgamate Sanmar Properties & Investments Ltd(SPIL) excluding its Investment and Shipping business w.e.f. Nov 2, 2003. SPIL's Investment and Shipping division would be demerged to Sanmar Holdings Ltd effective from Nov 1, 2003. SPIL sharehodlers get one equity share of Chemplast sanmar for every share in SPIL.