See Sen Chemical Berhad (See Sen) is the largest manufacturer of sulphuric acid in Malaysia.The company also produces derivatives of sulphur as listed here. The company's manufacturing facilities are located at Pasir Gudang (Johor) and Kemaman (Terengganu) respectively. The Kemaman plant is world-scale and utilizes imported Australian technology.

See Sen was established in 1967 and originally operated out of a site in Larkin Industrial Estate, Johor. Batu Kawan Berhad became the company's principal shareholder in 1983. In 1984, the new management commissioned a new acid plant in Pasir Gudang, Johor and the Larkin operation was eventually sold. The Kemaman plant was started-up in 1997. As with MSCI, the sales and distribution of the company's products are undertaken by Taiko Marketing Sdn. Bhd.