An aqueous solution, containing about 10 per cent, by weight of ammonia (NH3). On standing, this solution loses ammonia and hence should be kept in well-stoppered bottles and should frequently be tested by the pharmacist to insure its complying with the pharmacopeial requirements. Ammonia water is a colorless liquid, having a very pungent, characteristic odor and a caustic, soapy taste. It is freely miscible with water and alcohol.

Ammonia water is used chiefly for counterirritation in the form of: