Bhopal (former Union Carbide plant)

The plant made the pesticide Sevin (carbaryl) using methyl isocyanate as an intermediate. On the night of 3 December 1984 water entered a methyl isocyanate tank: in 45 to 60 minutes about 30 tonnes of gas escaped into the air, 40 tonnes within two hours. More than 500,000 people in the neighbourhoods around the factory were exposed.

The disaster did not end with the cloud. Process waste had been disposed of inside the perimeter, in a landfill and in solar evaporation ponds. Tests by Union Carbide's own laboratory in 1989 found that soil and water samples taken inside and near the factory were toxic to fish. In 1999 Greenpeace measured mercury in drain sediment at 20,000 to 6 million times the expected level, and organochlorine compounds in groundwater. In 2009 the Centre for Science and Environment found pesticide contamination of groundwater up to three kilometres from the factory.

In 1989 Union Carbide settled for about 470 million dollars. In 1998 the site passed to the Madhya Pradesh state government, which assumed responsibility for remediation. After a court order of 3 December 2024 requiring the site to be cleared within a month, on the night of 1 January 2025 a convoy of trucks under police escort took 377 tonnes of waste to the Pithampur incinerator, against protests from local people.