It all started with the manufacturing of flash light batteries in Calcutta by the Eveready Company Limited of Great Britain. Later on this company became a subsidiary of UCC headquartered in New York. The company later adopted the new name of Union Carbide India limited and also established a factory in India to manufacture flash lights along with expansion of its capacity to manufacture dry-cell batteries.

             The company progressed and by the eighties they were involved in batteries, carbon and metals, plastics, marine products, and agricultural chemicals. UCIL established fifteen plants in different parts of India. To expand its agricultural division UCIL sought permission of Indian government to allow them to set up a pesticide plant. Initially the plant was started near the city of Trombay but later on switched to Bhopal. The plant in the beginning imported Sevin powder from the United States diluted it with non-toxic powder and sold it. Later the Indian government pressurized UCIL to manufacture Sevein and its components in India. That's how the Bhopal plant expanded and the investment in the plant increased from initial $1 million to $25 million. The company made its mark among all companies present in India in terms of Sales.

             UCIL Bhopal.

             In Bhopal the UCIL factory was like any other process plant with storage tanks, hoppers and reactors connected by pipes, pumps, valves and ducts. Sevin was made through a chemical reaction between alpha-naphthol and methyl isocyanate, MIC. MIC is a highly reactive liquid that boils and becomes a gas above day time temperatures. UCC was the world leader in MIC technology and provided essentially al the process design for the plant but did not send engineers to supervise the construction. The alpha-naphthol unit began experiencing some problems. Also the sales were started going down in the beginning of 80s due to various reasons. Due to the decline in sales the unit started having losses.