With a theoretical decomposition energy of about 5 kJ/g, hydroxylamine is an explosive, and aqueous solutions above 80% can be easily detonated by detonator or strong heating under confinement.  At least two factories dealing in hydroxylamine have been destroyed since 1999 with loss of life. It is known, however, that ferrous and ferric iron salts accelerate the decomposition of 50%  solutions. Hydroxylamine and its derivatives are more safely handled in the form of salts.
It is an irritant to the respiratory tract, skin, eyes, and other mucous membranes. It may be absorbed through the skin, is harmful if swallowed, and is a possible mutagen.