Water Linked to Gas Leak at India Plant

It took just a little more than a pint of water to start the reaction that led to a deadly gas leak at Union Carbide’s Bhopal plant, killing 2,500 people, a scientist said today.

Dr. S. Varadarajan said the water turned one-third of the 45 tons of methyl isocyanate in the tank to a kind of plastic called polymer, generating so much heat that the rest of the liquid methyl isocyanate turned into gas.

“Just half a kilogram (about 17.6 ounces) of water entered the underground methyl isocyanate tank . . . triggering a runaway reaction that probably pulled the entire tank from the ground, causing cracks in its concrete shield,” the Press Trust of India news agency said.

The unscheduled talk, delivered at a scientific congress in the north central city of Lucknow, was the first official scientific account of the tragedy, the Press Trust of India said.

Varadarajan, chief of the Indian Council of Scientific and Industrial Research, said he believed that the reaction involved polymerization. If it had not, about 1 1/2 tons of water would have had to get into the tank in order to start a process that would turn the methyl isocyanate into gas, he said.

“He said it was not known ‘how this amount of water could have entered,’ ” the agency said.

The gas from the U.S.-owned Union Carbide pesticide plant spread through Bhopal, 360 miles south of New Delhi, on the night of Dec. 2-3, killing 2,500 people.