No federal agency is responsible for inspecting or regulating underground storage facilities to prevent accidental leaks of toxic gas into the atmosphere, as happened at a Union Carbied Corp. plant in India, officials said yesterday.

The gas, methyl isocyanate, killed hundreds of residents of the central Indian city of Bhopal after it leaked from a double-walled, presurized tank and a backup safety system apparently failed to neutralize the toxic fumes.

Large amounts of methyl isocyanate and closely related compounds are produced in the United States and held in similar storage units, but their handling and storage are generally regulated by industry standards rather than government rules.

Although there have been no major accidents involving releases of the chemical in this country, the tragedy in India has raised new questions about the safety of such facilities.

"We're as worried as everybody else," said Jim Stanley, an Occupational Safety and Health Administration official. Stanley and other OSHA officials said their agency generally is responsible for the safety of workers, not nearby residents.

"Release [of toxic materials] within the facility is our responsibility," Stanley said. If OSHA inspectors identified other leaks of toxic materials, he said, they typically would tell the Environmental Protection Agency.

EPA spokesman Robin Woods said that an emergency similar to the Bhopal accident could trigger the "Superfund" toxic cleanup law but that responsibility for preventing industrial accidents belongs to OSHA.

Though the EPA was authorized to regulate underground storage tanks under a new hazardous-waste law signed by President Reagan last month, it is not clear whether the power extends to release of toxic substances into the air.

John H. Skinner, who heads the agency's office of solid waste, said the new provisions are aimed at preventing contamination of water and soil. "The standards we would set would prevent leaks to the air in many instances, but that is not explicit under the rules," he said.

Skinner said the EPA expects to set temporary standards for new tanks within six months. The agency is allowed more than three years to set standards for existing tanks.

Meanwhile, the Bhopal accident also has prompted new concern over other health hazards associated with toxic substances.

Methyl isocyanate "is not the only highly toxic material being used here, and EPA isn't doing that much to help us," said Carl Beard, director fo the West Virginia Air Pollution Control Commission. A Union Carbide plant at Institute, W.Va., produces methyl isocyanate.

"There are design errors, there are screw-ups and life goes on," he said. "If things can happen, unfortunately they do happen. That's why we plan and have evacuation plans. That doesn't mean people like me sleep better at night."