Henry Welch, 80, a retired director of the antibiotics division at the Food and Drug Administration who was responsible for certifying penicillin during World War II, died of a heart ailment Oct. 22 at North Beach Hospital in Fort Lauderdale, Fla.

Dr. Welch, who lived in Lighthouse Point, Fla., was born in Newburyport, Mass. He graduated from Brown University, earned a master's degree there and a doctorate in bacteriology at Western Reserve University.

He moved to Washington in 1939 and joined the FDA, where he established the antibiotics division. Penicillin first became widely available during World War II, but even then it was in short supply. The problem was to devise ways to produce enough of it to meet the enormous needs of the military. Dr. Welch developed a pilot plant to turn out enough of it so that the safety and efficacy of the drug could be certified before being distributed to the armed services.

For this and other work he received the Distinguished Service Gold Medal of the Department of Health, Education and Welfare. He also received an honorary doctorate from Brown.

Dr. Welch headed the division of antibiotics until 1960, when he retired and moved to Florida.

He was the author of several books and numerous papers for professional journals. He was a fellow of the American Public Health Association and a member of the American Association of Immunologists. He chaired numerous symposia on antibiotics.

Survivors include his wife, Mary B., of Lighthouse Point; two children, Laura Crandall of Lighthouse Point, and David, of Pompano Beach, Fla.; a sister, Cora Welch of Newburyport, and two grandchildren.