One of the nation's largest chemical companies, citing "increased public concern" after the leakage that killed more than 2,000 people in India, announced yesterday that it intended to start publicizing information about its toxic products in the communities where it operates.

The St. Louis-based Monsanto Co. pledged to provide residents the same data on hazards and safety precautions that it gives to its employes and to police and fire officials.

The action goes significantly beyond what is required under federal right-to-know rules, which state only that workers directly involved in manufacturing hazardous products must be told of the potential perils.

Monsanto officials said that the step was prompted by a public clamor for more information about chemical hazards, which intensified last month after a poison-gas leak killed more than 2,000 neighbors of a Union Carbide Corp. chemical plant in Bhopal, India.

"People are tremendously more interested than they were before, and to tell them 'We're doing everything, don't worry' just isn't enough," said Richard J. Mahoney, Monsanto's president and chief executive officer. "I'd like to explain what we do and what our safeguards are. I think they're entitled to know that."

Monsanto's decision came as a surprise to some environmental activists, who have battled the chemical industry for years on the right-to-know issue and succeeded in winning a federal rule in 1983 only after the industry complained that it was being handcuffed by a proliferation of state and local rules.

"I think it's admirable," said Eric Draper, who works here for the National Campaign Against Toxic Hazards. "I could lose my line of work if chemical companies started acting responsibly."

Perry Bryant of West Virginia Citizen Action said the Monsanto decision could be of significant benefit to residents of the chemical-intensive Kanawha Valley, where neighbors of a Union Carbide plant learned that it was producing deadly methyl isocyanate only after the accident at its sister plant in Bhopal.

"I would certainly appreciate it if they'd provide any information," Bryant said. "The area we're most interested in is storage, given Bhopal, and in the safety devices for superhazardous materials. I hope this pronouncement covers this kind of material."

Monsanto is part of the Kanawha Valley chemical complex, with a plant in Nitro, W.Va.

The chemical industry has long resisted right-to-know rules, contending that releasing safety and health information would violate proprietary interests and make it impossible to protect trade secrets.

In a statement yesterday, Mahoney said the company would still seek to ensure "the security of our operations and, in rare cases, the protection of legitimate trade secrets."

But he added that "the emphasis of our efforts should be upon promoting public disclosure, not upon finding reasons for withholding information."

Monsanto officials said the decision is effective immediately, and applies to facilities abroad as well as in the United States.

An Occupational Safety and Health Administration official, who asked not to be identified, said Monsanto's disclosure move appears to be part of a trend among manufacturers of hazardous materials, who have become increasingly vulnerable to liability suits.

"The trade-secret mentality is being stripped away," he said. "If you don't label and you don't disclose, you could end up being liable. The reason tobacco companies are not being sued is because that warning label is there. It's the first-line shield of immunity to a lawsuit."

But Mahoney, in a telephone interview, called the decision "the kind of contemporary move you'd expect in this society. If my neighbor said to me, 'What are you making in there, anyway?' how could I say anything but, 'Come in and I'll show you'?"