Richard H. Carpenter, 33, who joined the U.S. Public Health Service about six months ago as freedom of information officer, died of cancer Sunday at the Southern Maryland Hospital Center in Clinton.

Prior to joining the Public Health Service, Mr. Carpenter had worked as a chemist for the Naval Ordnance Station at Indian Head. He also had been a chemist and a consumer safety officer for the Food and Drug Administration in Rockville.

Mr. Carpenter was born in Chattanooga, Tenn. He earned a bachelor's degree in chemistry from the University of Alabama in 1968. He moved to this area about 10 years ago and was a resident of Waldorf.

He was a member of the Alexandria Coin Club and had served as club president. In 1978, he received the club's "Numismatist of the Year" award.

Mr. Carpenter had attended the First Baptist Church of Gaithersburg.

Survivors include his wife, the former Sarah Stephens, and a daughter, Richelle, of the home in Waldorf; his parents, George B. and Eudora Carpenter, of Summerville, Ga.; five brothers, James B., of Marietta, Ga., Bob L., of Lompoc, Calif., Stanley L., of Jacksonville, Ala., George R., and Jesse R., both of Summerville; and a sister, Nellie C. Blocker, of Atlanta.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society.