Safety data for ammonium hydroxide

General

Synonyms: ammonia solution (typically contains between 12% and 44% ammonia before dilution), dilute ammonia, concentrated ammonia, ammonia aqueous, ammonia water. [Data for ammonia gas, NH₃, is available here.]
Molecular formula: NH₄OH
CAS No: 1336-21-6
EC No: 215-647-6
Annex I Index No: 007-001-01-2

Physical data

Appearance: colourless liquid
Melting point:
Boiling point: between 38 and 100 C depending upon concentration
Vapour density: 1.2
Vapour pressure: 115 mm at 20 C (depends on solution strength)
Specific gravity: typically 0.9 (depends on solution strength)
Flash point: none
Explosion limits: 16 - 27%
Autoignition temperature: 651 C

Stability

Stable. Incompatible with copper, copper alloys, acids, galvanised iron, zinc, aluminium, bronze, dimethyl sulphate, mercury, alkali metals.

Toxicology

Concentrated solution is extremely damaging to eyes. Even contact with dilute ammonia solution can lead to serious eye damage. Toxic if swallowed; harmful if inhaled and in contact with skin. Very destructive of mucous membranes. Corrosive - causes burns. Lachrymator. Typical TLV 25 ppm. Typical STEL 35 ppm. Typical PEL 50 ppm.

Toxicity data
(The meaning of any toxicological abbreviations which appear in this section is given here.)
ORL-RAT LD50 350 mg kg^-1
ORL-MAN LDLO 43 mg kg^-1
IHL-HMN LCLO 5000 ppm

Risk phrases
(The meaning of any risk phrases which appear in this section is given here.)
Annex I gives only R34 (causes burns) and R50 (very toxic to aquatic organisms) for concentrations above 25%; it specifies only R34 for concentrations between 10 and 25% and R36, R37 and R38 (irritant) for concentrations below 10%. However, concentrated ammonia is very harmful if splashed into the eyes, where it is likely to lead to serious permanent damage, so R41 should undoubtedly be specified for the more concentrated solutions. For these solutions of moderate concentration it would be prudent to include the following addition risk phrases: R20 R21 R22 R36 R37 R38 R41.

Environmental information

Dangerous in the environment.

Transport information

(The meaning of any UN hazard codes which appear in this section is given here.)
UN No 2672. Hazard class: 8.0. Packing group: III.

Personal protection

Good quality safety glasses with side protection against splashes. Good ventilation. Do not work in the open laboratory with concentrated ammonium hydroxide solution.

Safety phrases
(The meaning of any safety phrases which appear in this section is given here.)
S26 S36 S37 S39 S45 S61.

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