Ammo­nium nitrate may be the more likely can­di­date in the explosion.

In small quan­ti­ties, the white pel­lets won’t det­o­nate, notes Ronald Willey, a chem­ical engi­neering pro­fessor at North­eastern Uni­ver­sity in Boston. Many drug­store cold packs use the com­pound because, when water is also put in the packs, the mix­ture absorbs heat from its surroundings.

But the com­pound begins to decom­pose into nitrous oxide and water when heated to tem­per­a­tures above 150 degrees F. – a process that itself releases heat. If tem­per­a­tures rise to about 400 degrees F. or higher, as in a fire, decom­po­si­tion can become explosive.

Read the article at The Christian Science Monitor →