Didnt catch on fire but it did swell and vent on me. PEEEEEEEEEEE-EWWWWWWW!!! Dont breathe that stuff what ever you do! Granted it didnt smell as bad as when they actually catch fire but it still aint good! Took me an hour or more to ventilate the house. I need to find my respirator and make sure its handy in case that ever happens again. Pretty sure I shave a year of my life off breathing that stuff in opening windows in the basement in order to air the place out. One of the cats was just chillin' down there in the basement the whole time like she didnt even care. Pretty sure she has cancer now