Twenty-eight people sickened by a chemical leak from Union Carbide's plant in Institute, W.Va., Aug. 11 sued the company yesterday for a total of $86 million in damages.

One of the two lawsuits was filed in Kanawha County Circuit Court in Charleston, W.Va., the other in U.S. District Court in New York, where the firm is incorporated. Both accuse Carbide of negligence in allowing up to 500 gallons of a toxic chemical to escape from a temporary storage vessel.

The leak, consisting of the pesticide ingredient aldicarb oxime and the industrial solvent methylene chloride, sickened 142 people, including six Carbide employes. Plant officials said then that they waited about 20 minutes before alerting the community because they thought the leak was contained in the plant.

The New York suit was filed on behalf of seven Institute residents and a Jacksonville Beach, Fla., man who had been playing golf near the plant. It contends that Carbide failed to warn residents about the dangers of such spills, failed to alert the community immediately about the leak and failed to program its computer tracking system to monitor the cloud's movement.

The suit asks $3 million in compensatory damages and $5 million in punitive damages for each of the eight plaintiffs.

The Kanawha County suit, which is similarly worded, asks $100,000 in compensatory damages and $1 million in punitive damages for each of 20 plaintiffs.

Spokesman Tom Sprik said Union Carbide was aware of the suits, but he would not comment further on them. He said the company's investigation into the leak may yield a more detailed report by Friday.

Carbide announced that William D. Ruckelshaus, former head of the Environmental Protection Agency, has been appointed special counsel to head a board of directors' investigation.

John Coale, a Washington attorney representing plaintiffs in both suits, is also involved in litigation resulting from a leak last December at Carbide's plant in Bhopal, India, that killed more than 2,000 people. Coale said many residents of Institute and nearby Charleston are afraid to sue.

"There's a lot of fear that lawsuits or too much complaining might close down the plant," which provides 1,200 jobs in an area having high unemployment. "But that is not what we're after," he said. "We just want Union Carbide to do what they say they do -- and that's run a safe operation."