The operation was originally a chrome sulfate manufacturing facility of The Chromium Chemical Co., Ltd. It was purchased by a joint venture between Diamond Shamrock and Thai business interests in 1985. Then revamped to meet the international standard of Diamond Shamrock and restarted in January of 1986. Diamond Shamrock's interests were purchased by Occidental Chemical as part of the acquisition of Diamond Shamrock Chemical plants in 1986. The company name was changed from Thai Occidental Chemical Limited to Diachrome Chemicals Limited in February 2002.