Fire and medical officials have issued warnings about a supplement offered to Western wildland firefighters who have been exposed to toxic chemicals. Glutathione was given to some firefighters during California wildfires last year and again this month in Washington. Some firefighters have said it helped them feel better after breathing toxic smoke. The International Association of Fire Fighters, a first responders' labor union, has issued a safety advisory saying consumers should be cautious about glutathione's safety and claims that it can treat or prevent diseases. The advisory notes the supplement is not FDA approved. At least two pharmacies recalled glutathione in August due to bacterial contamination.