John H. Kay, 52, a consultant and researcher for the National Arademy of Sciences, died of a heart allment Sept. 30 at Georgetown University Hospital.

An authority on toxicology, he came here in 1973 to do research and write studies for the academy on chemistry, toxicology and related blomedical sciences.

Dr. Kay had served in the Army Medical Corps from 1943 to 1946.

Born in Stephenville, Tex, he traduated summa cum laude from Northwestern University, earning a doctorate in chemistry there in 1955. He remained at Northwestern through 1953 as an assistant professor of bacteriology.

Dr. Kay served as a consultant and worked for an number of firms and laboratories in the Chicago area before moving here.

A member of Phi Beta Kappa, he was a member of the Society of Texicologistute of Chemists. He belonged to the American Chemical Society and the American Association for the Advancement of Science.

He is survived by his wife, Doris M. of the home in Washington a son, Paul of Stephenville: a stepdaughter, Lisette S. Waser, in school in Switzerland; his mother, Maurine Kay, a sister, Mary Smith, and a brother, David all of Stephinville.

The family suggests that expresions of sympathy be in the form of contributions to the American Heart Association.