Diamond Shamrock

Diamond Shamrock Corporation was a diversified American industrial conglomerate that maintained a significant presence in the life sciences sector through its dedicated biosciences and animal health divisions. The company was a major producer of agricultural chemicals and veterinary medicines, most notably developing the widely used fungicide chlorothalonil (Daconil). During the 1980s, the company expanded its reach in the life sciences through SDS Biotech, a joint venture with Showa Denko focused on global agrochemical and animal health markets. Following a series of corporate restructurings and divestitures in the late 1980s, its life science assets were sold to various entities, while its refining and chemical businesses were eventually absorbed by Valero Energy and Occidental Petroleum.