Also in the early 1960s the company began using their granular activated carbon (GAC) for removing tastes and odors. In the early 1960s the Neville Island facility became the formation site of Pittsburgh Activated Carbon Company, the next evolution of the company. In 1965 the Calgon Corporation acquired Pittsburgh Activated Carbon. When Calgon Corporation was restructured in 1967 and split into six autonomous divisions, the Pittsburgh Activated Carbon Company division began operating its own marketing and manufacturing. Calgon Corporation was then acquired by Merck & Co. in 1968. In the late 1960s Pittsburgh Activated Carbon Company became increasingly involved with municipal drinking water treatment, and in 1970 the company's European marketing branch Chemviron opened headquarters in Brussels. Calgon Corporation formed a joint venture with Mitsui Chemicals and Mitsui & Co in 1978, branching into Japan. As of 1985, Calgon Carbon was operating as a subsidiary of Merck and Co. However, that year Calgon Carbon's management purchased their own company from Merck and Co in a leveraged buyout. Calgon Carbon made an initial public offering of common stock in 1987. Around 1990 the company came out with an "advanced UV oxidation process to remediate contaminated groundwater," and three years later Thames Water, a large utilities company in the United Kingdom, granted Calgon Carbon exclusive rights to market technology that cleaned organic compounds such as pesticides out of drinking water. Calgon Carbon was listed on the New York Stock Exchange in 1991, and throughout the 1990s it bought a number of subsidiaries, with Calgon Carbon's executive Colin Bailey overseeing many of the acquisitions. In 1996 it purchased the various operations of Vulcan Peroxidation Systems in Arizona and Solarchem Enterprises in Ontario, both of which produce perox-pure. Also that year Calgon Carbon acquired Advanced Separation Technologies in Florida and Charcoal Cloth (International) in Britain, the latter of which manufactures activated carbon in cloth form. In 1997 Calgon Carbon Asia was formed as a marketing subsidiary in Singapore, serving much of Asia, India, Australia and New Zealand. Calgon Carbon Corporation's CEO resigned in February 1998, reportedly over differences with the board of directors over company direction, and Calgon Carbon hired the firm Morgan Stanley for advice on a possible company sale. Also in 1998, the company developed a process to inactivate pathogens such as Cryptosporidium in drinking water, using UV disinfection. At that point the company launched two new products: ISEP for perchlorate removal using a continuous ion exchange system, and Sentinel UV Disinfection System, a disinfectant for pathogens.