McNeil, part of healthcare group Johnson and Johnson (J&J), said that customers had reported a “musty” smell as well as several cases of non-serious gastrointestinal upset.
The US firm attributed the odour to the presence of trace amounts of 2,4,6-tribromoanisole, a chemical which is used to treat the wooden pallets used to transport and store the drug’s packaging.
The problem first arose In November when McNeil pulled five batches of Tylenol. The firm said that the latest move is a further precautionary measure and stressed that: "To date all of the observed events reported to McNeil were temporary and non-serious."