Dr. Kligman has declined to be interviewed, or to discuss his experiments at any length. But, in a brief telephone conversation, he said: ''All those people could have leukemia now - about one chance in 20 billion. And I could be hit by an asteroid when I walk out on the street, but I don't think I will.''

He said he had given all his test records to Dow. ''I believe that included the names,'' he said. A Dow spokesman, Robert Charlton, said the company had never had the names. Health officials for the City of Philadelphia and Holmesburg, as well as Dow and Dr. Kligman, have told the environmental agency they have no records to help identify the men. Tests Disclosed in 1980

Dr. Kligman's tests for Dow were discovered by the E.P.A. in hearings the agency conducted in 1980 on whether the two Silvex and 2,4,5-T herbicides, which are restricted to some agricultural uses, should be prohibited altogether.

Hearing records provide ample documentation of the tests and how they were conducted, but offer no clues to the identities of the subjects except to show that most were black and ranged from 21 years of age to 49. They were paid for participating in the experiments.

Many cases of chloracne have occurred among workers in chemical plants, sometimes as a result of industrial accidents. Thousands were exposed to dioxin in a town in Italy in 1976 after an accident at a plant. In none of those cases, however, were exact degrees of exposure known.

Also, according to documents filed at the 1980 hearing, an earlier experiment by another Philadelphia doctor had tested solutions ranging from 2.5 percent to 10 percent of Silvex, which tends to contain a dioxin contaminant, on the skin of 51 volunteers, believed also to have been prisoners. At 5 percent, the solution caused ''primary skin irritation,'' according to a Dow summary of a report by Dr. Joseph V. Klauder, a dermatologist then also associated with the university. No Records or Names Found

Dr. Klauder died about 10 years ago. Neither his test records nor the names of his subjects are available. A chloracne outbreak at a Dow plant led a company official to commission the Kligman experiment. In a letter to Dr. Kligman in July 1965, the official, Verald K. Rowe, said he was sending TCDD to be used in the tests. He warned that the material ''is highly toxic'' and that an oral dose of onehalf to one microgram of it ''is always fatal'' in laboratory animals, with a ''typical clinical picture of severe liver and kidney injury.'' A microgram is one-millionth of a gram.