Ammonium perborate, NH₄BO₃

Ammonium perborate, NH₄BO₃.3H₂O, is obtained by dissolving boric acid in 2.5 per cent, hydrogen peroxide, adding ammonia, and precipitating with alcohol. When dried for twenty-four hours over sulphuric acid, the salt 2NH₄BO₃.H₂O is obtained, and this may be dehydrated over phosphoric anhydride.

The salt NH₄.BO₃.NH₄.BO₄.2H₂O has been described by Petrenko.