DANBURY, Conn. — The poison gas disaster that killed more than 2,000 people in Bhopal, India, last December may have been triggered by the "deliberate" pumping of up to a ton of water into a tank holding a volatile chemical, top officials of Union Carbide Corp. said Wednesday.
In their first public statement on the cause of the Bhopal tragedy, the officials said that water entering the tank unleashed a violent chemical reaction that spewed toxic methyl isocyanate gas from a pesticide factory operated by a Carbide subsidiary, Union Carbide India Ltd.
"We have not used the word 'sabotage,' " Union Carbide Chairman Warren M. Anderson said. "We're saying water got into the tank. We don't know how."
But Anderson said that the incident "doesn't sound like something that's inadvertent," adding: "It could have been a deliberate action."
The firm's two top safety experts said that it is "very difficult" to explain how the water could have accidentally entered the 15,000-gallon methyl isocyanate tank in which the reaction occurred.
The suggestion that water was deliberately pumped into the tank was made at a news conference at the company's headquarters here.
At the same time, Union Carbide admitted to a list of crucial operating violations and equipment breakdowns at the Bhopal plant--including breakdowns in a refrigeration unit, an alarm system and a flare tower that could have prevented release of the gas, or at least lessened its scope.
None of the three systems were operating at 12:15 a.m. on Dec. 3, when the temperature and pressure levels within tank 610 at the Bhopal factory soared out of control, Carbide spokesmen conceded.
By the time workers realized the extent of the danger, the plant operator "felt heat radiating from the tank" and heard a screeching sound from the safety valve designed to control gas releases, said Ron Van Mynen, head of a seven-member Union Carbide team that analyzed the Bhopal disaster.
Anderson said that the plant had been plagued by "a whole litany of non-standard operating procedures, omissions and commissions" in the weeks before the tragedy.
Of his colleagues' reaction during an inspection of the factory after the disaster, Van Mynen said, "I must admit that they were shocked by what they saw."
Anderson said repeatedly that, although Union Carbide accepts moral responsibility for the tragedy, any blame for lax supervision of the Bhopal plant rests with its American-trained Indian workers.
Safety Matters Delegated
The American corporation, which owns 50.9% of Union Carbide India Ltd., delegates most safety matters to its subsidiaries and did not know of problems at the Bhopal factory, he said.
In a complex 2 1/2-hour briefing, Anderson and other executives disclosed results of the eight-day inspection of the Bhopal plant by Van Mynen's team in late December. The report is to be turned over to the Environmental Protection Agency.
Union Carbide said that the inspectors documented a series of failures, in both the methyl isocyanate manufacturing and storage processes, that compounded the disaster.
The crucial refrigeration unit used to cool the plant's underground tanks of methyl isocyanate had been out of operation for five months at the time of the incident, in violation of Union Carbide standards, the executives said.
Alarm System Inoperative
The inoperative alarm system was designed to signal dangerous levels of heat within the tanks, they added, and the flare tower should have burned off any escaping gas.
In addition, they said the tank's contents were polluted by chloroform, used in manufacturing methyl isocyanate, fueling the chemical reaction begun by the water.
Although officials are certain that water contamination caused the runaway reaction, they could offer no simple explanation of how the water got into the tank.
Van Mynen said it is possible that water was "inadvertently or deliberately" pumped into tank 610 from nearby utility hookups that fed nitrogen and water to production points elsewhere in the plant. Such arrangements were found by the Union Carbide team at "a number of other places" in the plant, although not at tank 610, he said.
Spigot Error Possible
A worker could have inadvertently hooked a line from the methyl isocyanate tank into the utility hookup's water spigot, instead of the adjacent nitrogen spigot, he said.
But even that appears unlikely, Jackson Browning, Union Carbide's vice president for health and safety, said later. Not only were the utility hookups color-coded and labeled, but the spigots were of different sizes.
"It is very difficult for the team to explain how this large a quantity of water could get into the system," Van Mynen said.
Although Anderson agreed that the water contamination is difficult to explain, he refused to speculate on whether someone may have wanted to sabotage the plant.
'I Can't Impute Malice'
"Maybe somebody thought that, 'If I set a fire in this little house, I'll see the fire engines come,' " he said. "I can't impute malice here at all."
Both Anderson and Browning said that the findings of the Bhopal inspection would be applied to Union Carbide factories worldwide, including the Institute, W. Va., plant that also makes methyl isocyanate. The plant at Institute has been closed since the Bhopal disaster but will be reopened on April 1.
Anderson said it is unlikely that methyl isocyanate will ever be made again in India. But he said the company has no plans to leave India if government officials there allow it to stay.