<P> Ammonium nitrate - based explosives were used in the Sterling Hall bombing in Madison, Wisconsin, 1970, the Oklahoma City bombing in 1995, the 2011 Delhi bombings, the 2013 Hyderabad blasts, and the 2011 bombing in Oslo . </P> <P> In November 2009, a ban on ammonium sulfate, ammonium nitrate, and calcium ammonium nitrate fertilizers was imposed in the former Malakand Division--comprising the Upper Dir, Lower Dir, Swat, Chitral, and Malakand districts of the North West Frontier Province (NWFP) of Pakistan--by the NWFP government, following reports that those chemicals were used by militants to make explosives . Due to these bans, "Potassium chlorate--the stuff that makes matches catch fire--has surpassed fertilizer as the explosive of choice for insurgents ." </P> <P> Ammonium nitrate is used in some instant cold packs, as its dissolution in water is highly endothermic . It also was used, in combination with independently explosive "fuels" such as guanidine nitrate, as a cheaper (but less stable) alternative to 5 - aminotetrazole in the inflators of airbags manufactured by Takata Corporation, which were recalled as unsafe after killing 14 people . </P> <P> Health and safety data are shown on the safety data sheets available from suppliers and found on the internet . In response to several explosions resulting in the deaths of numerous people, U.S. agencies of Environmental Protection (EPA), Occupational Health and Safety (OSHA) and the Bureau of Alcohol, Tobacco and Firearms jointly issued safety guidelines . </P>

What happens when ammonium nitrate reacts with water