Silver Spring, Md. ? Federal scientists urged stronger warning labels Thursday on every bottle of acetaminophen, based on evidence that thousands of Americans may unwittingly take toxic doses that could harm their livers.

“You cannot allow more innocent men, women and children to suffer,” Kate Trunk, whose 23-year-old son Marcus was one of about 100 people thought to die every year from unintentional overdoses, told a panel of Food and Drug Administration advisers. “Death is not an acceptable side effect.”

The FDA panel voted 21-1 to back her call for more warnings about the risk.

Some 100 million people a year take acetaminophen, and serious liver damage is rare, manufacturers insist.

Although best known by the Tylenol brand, acetaminophen is in almost 200 branded and generic products, from headache relievers to cold-and-cough remedies. While mostly sold without a prescription, it’s also in a few prescription painkillers.

Acetaminophen bottles currently recommend taking no more than 4 grams a day, or eight extra-strength pills, and to seek help for overdoses.

Unintentional overdoses also can destroy the liver. Consumers often swallow a few extra pills in hopes of faster pain relief, falsely thinking that over-the-counter medications are safe enough to push the dose. Because acetaminophen is in so many products often listed merely in the fine print taking a few different remedies the same day can mean unknowingly ingesting potentially toxic amounts.

And some scientists warn that even taking the maximum safe dose for a long period, instead of the recommended day or two, may be risky. The question is how to tell who is at risk.

Acetaminophen is safe, but “people misuse these products,” acknowledged Dr. Anthony Temple, vice president of McNeil Consumer & Specialty Pharmaceuticals, Tylenol’s maker. So McNeil is about to place new warnings on all its acetaminophen products to say that “taking an overdose may cause liver damage.”