Hydroxylammonium is an easily-handled form of hydroxylamine, which is explosive when pure. Hydroxylammonium sulfate is used in the production of anti-skinning agents, pharmaceuticals, rubber, textiles, plastics and detergents. It is a radical scavenger that terminates radical polymerization reactions and serves as an antioxidant in natural rubber. (NH3OH)2SO4 is a starting material for some insecticides, herbicides and growth regulators.

It is used in photography as a stabiliser for colour developers and as an additive in photographic emulsions in colour film. (Source Wikipedia)

In dangerous goods regulations Hydroxylammonium sulphate is listed under class 8 (corrosive substances) UN 2865 HYDROXYLAMINE SULPHATE

International Chemical Safety Card 0898

Sigma-Aldrich Hyroxylamine Sulphate