Motrin, Tylenol, Rolaids, Benedryl and St. Joseph’s Aspirin are being recalled today by Johnson & Johnson unit McNeil Consumer Healthcare because they may be tainted with a chemical that causes a moldy smell, and could cause stomach illness.

Any smell is likely the result of contamination with trace amounts of a chemical called 2,4,6-tribromoanisole. The source of 2,4,6-tribromoanisole is believed to be the breakdown of a chemical used to treat wooden pallets that transport and store packaging materials. The health effects of this compound have not been well studied, but McNeil said that so far, to date all of the reported adverse reactions have been temporary and non-serious.

Last November, McNeil recalled 5 lots of Tylenol Arthritis Pain Caplet 100 count bottles, with the distinctive red EZ-OPEN CA because of reports of the odor, which was associated with nausea, stomach pain, vomiting and diarrhea. That recall was expanded in December to include all lots of the product.

Now, McNeil is recalling more products that might be tainted with the same chemical. Since the December recall, the company said it has now applied broader criteria to identify and remove all product lots that may be affected, even if they have not been the subject of consumer complaints. McNeil also said it was ceasing shipment of products produced using materials shipped on the wood pallets and requiring suppliers to stop using the pallets.

The recall involves lots in the Americas, the United Arab Emirates (UAE), and Fiji. A complete list of recalled products is available here, or call 1-888-222-6036 (Monday-Friday 8 a.m. to 10 p.m. Eastern Time, and Saturday-Sunday 9 a.m. to 5 p.m. Eastern Time).

McNeil has not been able to determine how the chemical may have penetrated product packaging.