Ammonium chloride

• BPAmmonium Chloride
• Ph. Eur.Ammonium Chloride
• USP–NFAmmonium Chloride

Ammonii chloridum; ammonium muriate; sal ammoniac; salmiac; E510

Ammonium chloride · [12125-02-9]

UNII 01Q9PC255D · PubChem CID 25517

NH4Cl · 53.49

pH adjuster, buffering agent

Typical concentrations: — · Dosage forms: Liquid

Used as an acidifying agent and, with ammonia, as an ammonia–ammonium chloride buffer, and in some oral expectorant and cough preparations, where it is also an active ingredient. In foods it is used as a flavouring (for example in salty liquorice) and as a yeast nutrient and dough conditioner.

Colourless crystals or a white, odourless, crystalline powder with a cool, saline taste.

Behaviour on heating

sublimes at about 340 °C without melting, dissociating into ammonia and hydrogen chloride

Density

≈ 1.53 g/cm³

pH

about 4.5–6 (5% w/v aqueous solution)

Solubility

freely soluble in water (about 37 g per 100 g water at 20 °C), more soluble in hot water; sparingly soluble in ethanol; soluble in glycerol

Hygroscopicity

slightly hygroscopic

Stable, but slightly hygroscopic and may cake. Store in an airtight container in a cool, dry place.

Liberates ammonia with alkalis and alkali carbonates. Incompatible with silver and lead salts, with strong oxidising agents such as potassium chlorate, and with nitrites; it can corrode metals in the presence of moisture.

Made by neutralising ammonia with hydrochloric acid, or recovered as a by-product of the ammonia–soda (Solvay) process, then purified by crystallisation.

At the levels used as an excipient it is of little concern. Large oral doses cause gastric irritation, nausea and vomiting and can produce metabolic acidosis; it should be avoided in patients with impaired hepatic or renal function.

Observe normal precautions for the quantity handled. Eye protection and gloves are recommended; heating releases irritant fumes of ammonia and hydrogen chloride.

GRAS listed. Accepted as a food additive in Europe (E510). Used in oral medicines licensed in Europe.

Ammonia solution; ammonium carbonate; potassium chloride; sodium chloride.

Ammonium chloride dissolves endothermically, so solutions cool noticeably as it dissolves. Its acidifying effect in the body comes from conversion of the ammonium ion to urea in the liver, which is why hepatic impairment is a contraindication at therapeutic doses.