Following his internship, residency, and a two-year term services in the
Army Medical Corps, he became an
assistant professor of medicine and pharmacology at Cornell in 1968, and became a director of clinical pharmacology at the
Pennsylvania State University Medical School in 1972. The
Chicago Tylenol murders in 1982, caused nationwide alarm after seven people died after taking
Extra-Strength Tylenol capsules which had been laced with
potassium cyanide. Under Hayes' leadership, the government and the drug industry responded by developing the first federal regulations requiring
tamper-evident packaging for all
over-the-counter drugs. He was finally investigated for accepting free lodging and travel from industry trade groups, double billing, and questionable reimbursements for private speaking engagements. He resigned on September 11, 1983, to become dean and provost of New York Medical College in Valhalla, N.Y. and was named president of EM Pharmaceuticals Inc. ==Death==