(FORTUNE Magazine) – THE RISING CLAMOR for legislation forcing chemical companies to disclose potential risks at their plants has the companies in a quandary. They'd rather not have to contend with a stringent new federal law, but after the accident that killed more than 2,000 people in Bhopal, India, last fall, they can hardly mount a vigorous campaign against it. Even before the tragedy, 21 states and 40 communities had passed so-called right-to-know laws, and now the pace is quickening. The industry would like to head off the emerging patchwork of state and local laws. ''It creates a nightmare when we have not one but 50 rules judging us,'' says Lawrence Birkner, manager of safety at Atlantic Richfield. Companies argue that they are better equipped than local communities to develop programs for labeling hazardous products and training workers to handle them. They also resist on grounds that such laws would force them to disclose proprietary information that could be useful to competitors. However, they're not quite sure what to do about a tough new bill New Jersey Democrat James Florio recently introduced in the House. Says Geraldine Cox of the Chemical Manufacturers Association, ''We don't think legislation is necessary, but we probably wouldn't oppose it.'' A disclosure ruling by the Occupational Safety and Health Administration is due to take effect at the end of this year. The companies would prefer to live with that rule, though they would be willing to see it strengthened. But many unions and local consumer groups charge that the OSHA rule--which they call a right-to-hide law--allows companies to conceal the identity of chemicals by claiming that the information is proprietary. Lobbyists for the industry are trying to steer the debate toward a discussion of emergency procedures rather than toward more disclosure of what's in the products being made. ''Does everyone have to know every chemical in our facilities?'' asks Birkner. ''Isn't the real issue how to respond to emergency situations?'' Cox says many companies already have such programs but that the industry is suffering from a public relations problem. ''We have failed to tell the communities about our programs,'' she says. At least one company is mounting a P.R. offensive. Monsanto has urged its 130 plant managers around the world to take area residents on plant tours, to hold town meetings, and to discuss emergency evacuation procedures. Dow, Du Pont, Atlantic Richfield, and others are considering high-profile programs, though they say they've had disaster plans for years. On Capitol Hill, one company that's being especially cooperative is Union Carbide, principal owner of the Bhopal plant. Says a congressional aide, ''It can't afford to be against us now.''