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CHEMINFO Record Number: 659
CCOHS Chemical Name: Ammonium formate

Formic acid, ammonium salt
Formate d'ammonium

CAS Registry Number: 540-69-2
RTECS Number(s): BQ6650000
EU EINECS/ELINCS Number: 208-753-9
Chemical Family: Saturated aliphatic carboxylic acid salt / saturated aliphatic monocarboxylic acid salt / alkanoic acid salt / formate / ammonium salt
Molecular Formula: C-H5-N-O2
Structural Formula: H-CO2-.NH4+


Appearance and Odour:
White crystals, crystalline powder or granules; deliquescent (absorbs moisture from the air and forms wet solid or solution); may have odour of ammonia and formic acid.(2)

Odour Threshold:
Not applicable; odour results from decomposition products.

Warning Properties:
Insufficient information for evaluation.

Ammonium formate is one of the soluble salts of formic acid. It has similarities (properties and hazards) to other formates as well as other ammonium salts. This record contains the available information specific for ammonium formate, supplemented with general information on ammonium and formate salts which is applicable to ammonium formate. It is available commercially in grades of 97% and 99% or greater.(1)

Uses and Occurrences:
Major use in analytical chemistry, as a metal precipitant or as a reductant in catalytic hydrogen transfer reactions; buffer.(1,2)


White, deliquescent crystals, crystalline powder or granules, with a slight ammoniacal and formic acid odour. POTENTIAL COMBUSTIBLE DUST HAZARD. Dry powdered material may form explosive dust-air mixtures. Thermally decomposes to form toxic/irritating ammonia. Essentially non-toxic.


Effects of Short-Term (Acute) Exposure

The limited information available indicates that ammonium formate is practically non-toxic. High concentrations of dust or mist (from solutions) may cause coughing and mild, temporary irritation.

Skin Contact:
Based on a related chemical, ammonium acetate, concentrated solutions of ammonium formate may cause mild skin irritation. The dust is probably not irritating. Ammonium formate is probably not absorbed through the skin to a significant extent.

Eye Contact:
Concentrated solutions may cause eye irritation, based on information for other ammonium salts such as ammonium chloride.(3) For dust, some tearing, blinking and mild, temporary pain may occur as the solid material is rinsed from the eye by tears.

Based on animal studies, ammonium formate is very low in oral toxicity. Large doses may produce nausea and vomiting, based on information for ammonium chloride.(4)
A very small possibility exists that ingestion of large amounts of ammonium salts may produce ammonia poisoning, particularly in persons with pre-existing liver disease. Symptoms may include impaired motor performance, tremor, confusion, generalized discomfort, anxiety and coma.(5) Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

SKIN: Prolonged or repeated contact with solutions of ammonium formate can probably cause redness, drying and cracking of the skin (dermatitis).


No animal or human information is available.

The International Agency for Research on Cancer (IARC) has not evaluated the carcinogenicity of this chemical.

The American Conference of Governmental Industrial Hygienists (ACGIH) has no listing for this chemical.

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
No animal or human information is available.

Reproductive Toxicity:
No animal or human information is available.

No specific information is available.

Toxicologically Synergistic Materials:
No information available.

Potential for Accumulation:
Ammonium formate can enter the body by inhalation or ingestion. It does not accumulate. Ammonium and formate ions are normally found in the body. The ammonium ion is rapidly converted to urea, which is excreted in the urine, and free formate ion, which is completely metabolized. Formate is a product of intermediary metabolism and is incorporated into some chemicals in the body.(5)


If symptoms are experienced, remove source of contamination or move victim to fresh air and obtain medical advice.

Skin Contact:
No health effects expected. If irritation does occur, flush with lukewarm, gently flowing water for 5 minutes or until the chemical is removed. If irritation persists, obtain medical advice.

Eye Contact:
Do not allow victim to rub eye(s). Let the eye(s) water naturally for a few minutes. Have victim look right and left, and then up and down. If the particle/dust does not dislodge, flush with lukewarm, gently flowing water for 5 minutes or until particle/dust is removed, while holding the eyelid(s) open. If irritation persists, obtain medical attention. DO NOT attempt to manually remove anything stuck to the eye(s).

No health effects expected. If irritation or discomfort occur, obtain medical advice immediately.

First Aid Comments:
All first aid procedures should be periodically reviewed by a physician familiar with the material and its conditions of use in the workplace.


Flash Point:
Not applicable. Ammonium formate does not form a vapour.

Lower Flammable (Explosive) Limit (LFL/LEL):
Not applicable.

Upper Flammable (Explosive) Limit (UFL/UEL):
Not applicable

Autoignition (Ignition) Temperature:
Not available

Sensitivity to Mechanical Impact:
Stable material. Probably not sensitive.

Combustion and Thermal Decomposition Products:
Ammonia, and nitrogen oxides.(8)

Flammable Properties:

Extinguishing Media:
Use extinguishing media suitable for surrounding fire.

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance or a protected location. Approach fire from upwind to avoid hazardous vapours and toxic decomposition products.
Avoid generating dust to minimize risk of explosion. Water can be used in the form of spray or fog to prevent dust formation, absorb heat, keep containers cool and protect fire-exposed material. Solid streams of water may be ineffective and spread material.
Although ammonium formate is only slightly hazardous to health, it can thermally decompose forming toxic and irritating ammonia. Therefore, do not enter without wearing specialized protective equipment suitable for the situation. Firefighter's normal protective clothing (Bunker Gear) will not provide adequate protection. A full-body encapsulating chemical resistant suit with positive pressure self-contained breathing apparatus (NIOSH approved or equivalent) may be necessary.


NFPA - Comments:
NFPA has no listing for this chemical in Codes 49 or 325.


Molecular Weight: 63.06

Conversion Factor:
Not applicable

Physical State: Solid
Melting Point: 116 deg C (241 deg F) (2,10)
Boiling Point: Decomposes at 180 deg C (356 deg F) (10)
Relative Density (Specific Gravity): 1.28 (water = 1) (10,11)
Solubility in Water: Very soluble in water (102 g/100 mL at 0 deg C).(10)
Solubility in Other Liquids: Soluble in ethanol, diethyl ether and liquid ammonia.(10)
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available
pH Value: Practically neutral; 5.5-7.5 (1M solution in water at 25 deg C) (1)
Vapour Density: Not applicable
Vapour Pressure: Not available.
Saturation Vapour Concentration: Not applicable
Evaporation Rate: Not available
Critical Temperature: Not applicable


Normally stable. Ammonium formate can slowly break down (dissociate) to release ammonia and formic acid vapours.

Hazardous Polymerization:
Will not occur

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.

STRONG OXIDIZING AGENTS (e.g. sodium hypochlorite) - may react violently or explosively.(8)
STRONG ACIDS - may react vigorously and decompose ammonium formate to produce formic acid vapours.(8)
STRONG BASES - may react vigorously and decompose ammonium formate to produce ammonia gas.

Hazardous Decomposition Products:
Ammonia, formic acid

Conditions to Avoid:
Static charge, sparks, heat and other ignition sources, generation of dust.

Corrosivity to Metals:
Very weakly corrosive to stainless steel, aluminum and nickel and its alloys.(12)


LD50 (oral, mouse): 2250 mg/kg (6)

No other animal toxicity information was located.


Selected Bibliography:
(1) Fluka Chemika-BioChemika 1995/96. Fluka Chemie AG, 1995. p. 122
(2) The Merck index: an encyclopedia of chemicals, drugs, and biologicals. 11th edition. Merck & Co., Inc., 1989. p. 85
(3) Grant, W.M. Toxicology of the eye. 4th edition. Charles C. Thomas, 1993. p. 131
(4) Martindale: the extra pharmacopoeia. 29th edition. The Pharmaceutical Press, 1989. p. 905
(5) Gosselin, R.E., et al. Clinical toxicology of commercial products. 5th edition. Williams & Wilkins, 1984. p. II-123, III-23 - III-26
(6) Malorny, G. Acute and chronic toxicity of formic acid and formates. Zeitschrift fur Ernaehrungswissenschaft. Vol. 9, no. 4 (1969). p. 332-339
(7) Field, P. Explosibility assessment of industrial powders and dusts. Building Research Establishment, 1983
(8) The Sigma-Aldrich library of chemical safety data. Edition II. Volume 2. Sigma-Aldrich Corporation, 1988. p. 236B
(9) Fire protection handbook. 17th edition. National Fire Protection Association, 1991. p. 2-332 to 2-333, 3-133 to 3-142
(10) CRC Handbook of chemistry and physics. 64th edition. CRC Press, 1983. p. B-68
(11) HSDB record for ammonium formate. Date of last update: 9412
(12) Corrosion data survey : metals section. 6th edition. National Association of Corrosion Engineers, 1985. p. 10-11
(13) National Institute for Occupational Safety and Health (NIOSH). Particulates Not Otherwise Regulated, Total. In: NIOSH Manual of Analytical Methods (NMAM(R)). 4th ed. Edited by M.E. Cassinelli, et al. DHHS (NIOSH) Publication 94-113. Aug. 1994. Available at: <>
(14) National Institute for Occupational Safety and Health (NIOSH). Particulates Not Otherwise Regulated, Respirable. In: NIOSH Manual of Analytical Methods (NMAM(R)). 4th ed. Edited by M.E. Cassinelli, et al. DHHS (NIOSH) Publication 94-113. Aug. 1994. Available at: <>

Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.

Review/Preparation Date: 1995-10-25

Revision Indicators:
EU number 1996-06-01
EU class 1996-06-01
US transport 1996-06-01
Vapour pressure 1996-06-01
Personal protective equipment 1996-06-01
Resistance of materials 1998-06-01
Bibliography 2005-03-20
Sampling/analysis 2005-03-20

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