This page describes feed grade ammonium chloride as a chemical: why a strong-acid, weak-base salt acidifies, what the purity specification is actually controlling, and how the material behaves in premix and liquid formulation. Its role in animal nutrition — urinary acidification, urolithiasis prevention and DCAD management — is covered on the animal feed grade page in the nitrogen fertilizer section.
Substance identity
| Chemical name | Ammonium chloride |
| Synonyms | Sal ammoniac, salmiac, ammonium muriate |
| Formula | NH₄Cl |
| CAS | 12125-02-9 |
| PubChem CID | 25517 |
| Molar mass | 53.49 g/mol |
| Appearance | White crystalline powder or fine granules, odourless when dry |
Specification
| Parameter | Value | Basis |
|---|---|---|
| NH₄Cl content, dry basis | ≥ 99.3 % | Typical commercial range |
| Moisture | ≤ 0.5 % | Typical commercial range |
| Water-insoluble matter | Low; specify a maximum | To be agreed |
| Heavy metals, as Pb | ≤ 10 mg/kg | Typical commercial range |
| Arsenic (As) | ≤ 2 mg/kg | Typical commercial range |
| pH, 5 % solution at 25 °C | 4.5–6.0 | Typical range |
| Appearance | White, free-flowing | — |
These are typical commercial values. Binding limits are those of the feed legislation applicable in the country of use; where they differ, the regulation governs. Confirm current authorisation status in the destination market.
Properties
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Acid–base behaviour. Ammonium chloride is the salt of a strong acid and a weak base. In water it dissociates fully, and the ammonium ion — conjugate acid of ammonia, pKa 9.25 at 25 °C — hydrolyses to release hydrogen ions. This is why a neutral-looking white salt gives an acidic solution, and it is the chemical basis of every acidifying application the material has.
-
Buffering. Mixed with ammonia, ammonium chloride forms a standard buffer system with a buffer centre near pH 9.25. This is a laboratory use of the pair rather than a feed application, but it is the same equilibrium seen from the other side.
- Solubility. Approximately 37 g per 100 g water at 20 °C; sparingly soluble in ethanol; essentially insoluble in acetone and diethyl ether.
- Dissolution enthalpy. Endothermic, about +14.8 kJ/mol.
- Hygroscopicity. Critical relative humidity near 77 % at 30 °C.
- Thermal behaviour. Dissociates to NH₃ and HCl on heating; apparent sublimation near 337.6 °C; no melting under ordinary conditions.
Applications
Supplied as a feed additive for ruminant rations and as a component of premixes and liquid supplements. Two formulation properties govern its handling. Its high solubility makes it straightforward to dose in drinking water and liquid feed, but the endothermic dissolution means a large charge added at once will cool the batch and slow its own dissolution — add incrementally with agitation. Its acidity should be accounted for in any formulation where pH affects the stability of other components, since a highly soluble acid-generating salt can shift a batch pH more than its mass fraction suggests.
Handling and storage
Store dry and sealed, segregated from agricultural- and technical-grade material with dedicated handling equipment. In premixes, caking is a homogeneity failure rather than a cosmetic one: a caked additive cannot be distributed uniformly, and uniformity is what makes the inclusion rate meaningful. Control dust — the material is classified as harmful if swallowed and as causing serious eye irritation. Keep away from strong alkalis, which liberate ammonia gas, and from strong oxidisers. In moist conditions the salt attacks copper alloys, mild steel and galvanised surfaces, so mixing and conveying equipment should be selected accordingly.
Notes
Purity in a feed specification is doing two jobs. The assay figure confirms you are paying for active material; the contaminant limits confirm the material is fit to enter the food chain. The second is the one that distinguishes feed grade from technical grade, and it cannot be inferred from a high assay figure — a 99.5 % technical grade is not automatically compliant with feed contaminant limits, because the two specifications control different things.