Union Carbide Corp., which suspended production of methyl isocyanate at its Institute, W.Va., plant after a massive leak of the chemical at its facility in Bhopal, India, in December killed at least 2,000 people, announced yesterday that it hopes to resume making MIC at the West Virginia plant about April 1.

The company said the plan is contingent upon completion of its investigation of the Bhopal tragedy and implementation of any recommended changes at Institute, the only place in the United States where MIC was manufactured.

Rep. Henry A. Waxman (D-Calif.), whose health and environment subcommittee held a hearing at Institute on Dec. 14, reacted to yesterday's announcement by saying, "I plan to hold Union Carbide Board Chairman Warren Anderson to his commitment to our subcommittee not to restart the Institute plant until we have a complete understanding of what happened in Bhopal and . . . are assured that it cannot happen here."

Perry Bryant of the West Virginia Citizens Action Group said he was appalled by the announcement, but knew of no state or federal law prohibiting the company from resuming production, or requiring community consultation beforehand. "We are essentially powerless," Bryant said.

Most state and federal officials said the key to resuming production is what is learned from the Bhopal inquiry.

Jim Makris, head of the Environmental Protection Agency's MIC task force, said the firm's announcement "gives us a time frame to know what happened in Bhopal."

Makris said a technical team from EPA and the Occupational Safety and Health Administration will be sent to Institute before production resumes to work with state and company officials to ensure safety. He said that although the company does not need permission to resume production, several regulations, including the Toxic Waste and Clean Air acts, could be invoked to halt production if federal officials are not convinced that every safety precaution has been taken.

Thad D. Epps, a Union Carbide spokesman, said changes being considered include making smaller batches of MIC and converting all of it to end-products at Institute, rather than shipping it to other Carbide plants and customers. He noted that MIC has been made safely at Institute for 17 years.

Reopening the MIC unit has economic implications. Epps said nearly half the plant's 1,500 workers are involved in the production of MIC, a major ingredient in the pesticide Sevin and other products.

Rep. Robert E. Wise Jr. (D-W.Va.), whose district includes Institute, said he was glad to hear of the announcement because "the issue has never been whether Carbide would resume production of MIC," but rather how to make production of all chemicals safer. Carbide is just one of more than a dozen chemical companies in the Kanawha Valley around Charleston that make toxic chemicals.

In Homer City, Pa., yesterday, 59 workers were taken to hospitals after breathing toxic chlorine gas that swept through a coal-fired power station. Workers were flushing sludge out of a chlorine tank when liquid waste backed up in floor drains and the colorless fumes escaped into the basement. And in Middlesex, N.J., one man was killed, 10 persons hurt and dozens evacuated after explosions ripped through a paint factory.

Also yesterday, Waxman, broadening his probe of safety in the chemical industry, said he has asked U.S. chemical companies to respond in two weeks to his request to identify dangerous chemicals in their inventories, estimate the amount of poison gases regularly leaking into the air and the adverse health effects, and evaluate the potential for major poison gas leaks.

"I was very distressed to learn that no government agency has even attempted to collect this information," Waxman said. "The EPA, which has responsibility for protecting our nation's air supply, has no idea what's coming from these plants," he said, adding that the agency "does not even have an up-to-date list of where the chemical plants in this country are."

EPA spokesman Dave Cohen said it is "slightly unfair criticism to suggest that EPA can be responsible for every company in this country that utilizes chemicals." He said EPA is updating files but "I'm sure we don't know exactly where every chemical plant in the country is. I'm sure he won't find out either."