 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.The solution of ammonium nitrate with nitric acid, called Cavea-b showed promise for use in spacecraft as a more energetic alternative to the common monopropellant hydrazine.