In addition to great replies so far, remember that there was a huge Batch recall by McNeil Consumer Healthcare in 2010.
Refer FDA Warning Letter
here
The company received "uncharacteristic odor" complaints, some of which were associated with adverse event reports (gastrointestinal distress), for several of your OTC drug products are due to 2,4,6 Tribromoanisole (TBA) contamination in the product and/or bottles. TBA, which has a musty, mildew-type odor, is a known degradant of 2,4,6, Tribromophenol (TBP). TBP is a pesticide and flame retardant used to treat wooden pallets for transporting packaging materials and finished product. TBA is organoleptically detectable at parts per trillion.
The company also inferred that uncharacteristic odor was due to the contamination of the drug product containers from TBP treated wooden pallets, where TBP from the wooden pallets degraded into TBA, which contaminated product containers and the finished product in those containers.
Also refer an existing thread -
US Federal Regulation(s) on Wooden Pallets
.