During the last decade, more than 1,500 Americans died after accidentally taking too much of a drug renowned for its safety: acetaminophen, one of the nation’s most popular pain relievers. Acetaminophen – the active ingredient in Tylenol, produced by McNeil Consumer Healthcare, a unit of Johnson & Johnson – is considered safe when taken at recommended doses. Yet a new investigation by Pro Publica shows that federal regulators have delayed or failed to adopt measures designed to reduce deaths and injuries from acetaminophen overdose, which the agency calls a “persistent, important public health problem.” The FDA has repeatedly deferred decisions on consumer protections even when they were endorsed by the agency’s own advisory committees, records show.