Which chemical was linked to the odor problem behind the 2009–2010 recall of some Tylenol products?

2,4,6-Tribromoanisole was linked to the odor problem behind the 2009–2010 recall of some Tylenol products.

McNeil Consumer Healthcare recalled numerous medicines after consumers reported a musty or moldy odor. Investigators linked the smell to 2,4,6-tribromoanisole, or TBA. The compound formed when a preservative used on wooden pallets reacted with a flame retardant in the pallet material.

The recalled products included certain Tylenol medicines and other brands manufactured by McNeil. Some consumers reported nausea, stomach pain, vomiting, and diarrhea, although regulators did not identify a serious health hazard from the odor itself in every case.

The episode is often confused with the 1982 Tylenol murders, which involved deliberate cyanide tampering. The later recall concerned manufacturing and packaging odors, not criminally poisoned capsules.