Posted in Web Union Carbide India Ltd, Bhopal, India. 3rd December 1984 May 17, 2019 Union Carbide India Ltd, Bhopal, India. 3rd December 1984 Accident summary. In the early hours of 3 December 1984 a relief valve on a storage tank containing highly toxic methyl isocyanate (MIC) lifted. : http://www.hse.gov.uk/comah/sragtech/caseuncarbide84.htm