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CHEMINFO Record Number: 603
CCOHS Chemical Name: Magnesium formate

Formic acid, magnesium salt
Formate de magnésium

CAS Registry Number: 557-39-1
Chemical Family: Saturated aliphatic carboxylic acid salt / saturated aliphatic monocarboxylic acid salt / alkanoic acid salt / formate / magnesium salt
Molecular Formula: C2-H2-Mg-O4
Structural Formula: (H-COO--)2.Mg++


Appearance and Odour:
Colourless crystals or granules.(1,2)

Odour Threshold:
Information not available

Warning Properties:
Insufficient information available for evaluation.

Magnesium formate is one of the soluble salts of formic acid. It has many similarities (properties and hazards) to other formates. This record contains the available information specific for magnesium formate, supplemented with general information on formate salts which is applicable to magnesium formate. It is available in a dihydrate crystalline form.(1)

Uses and Occurrences:
Major use is in analytical chemistry.(2)


Colourless crystals or granules. POTENTIAL COMBUSTIBLE DUST HAZARD. Powdered material may form explosive dust-air mixtures. May form highly flammable hydrogen gas during a fire. Essentially non-toxic.


Effects of Short-Term (Acute) Exposure

No animal or human inhalation studies have been reported. It is expected that magnesium formate causes only minor, reversible effects on the lungs. Based on information for related formates, high concentrations of dust or mist (from solutions) can cause irritation of the upper respiratory tract.

Skin Contact:
No human or animal information available. Magnesium formate solutions may cause skin irritation.

Eye Contact:
No human or animal information available. Mists or solutions may cause eye irritation. 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 and human information for other formate salts, magnesium formate is probably low in oral toxicity. Based on human information for sodium formate, ingestion of small doses (less than 1 g) would probably not produce ill effects. Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

SKIN: Prolonged or repeated contact with solutions 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:
Does not accumulate. Formates are rapidly broken down and eliminated from the body.


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. Magnesium 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:
Probably not sensitive. Stable material.

Combustion and Thermal Decomposition Products:
Information not available. At elevated temperatures, it may decompose into magnesium oxalate and hydrogen and then into magnesium carbonate. Under fire conditions, carbon monoxide and carbon dioxide may be formed.

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. Flammable hydrogen gas may be formed under fire conditions.
Avoid generating dust to minimize risk of explosion. Water can be used in the form of spray or fog to present dust formation, absorb heat, keep containers cool and protect fire-exposed material. If a leak or spill has not ignited, use water spray to disperse the vapours and to protect personnel attempting to stop a leak. Water spray may be used to flush spills away from ignition sources. Solid streams of water may be ineffective and spread material.
As in any fire, wear self-contained breathing apparatus (SCBA), pressure-demand, (MSHA/NIOSH approved or equivalent) and full protective equipment (Bunker Gear).


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


Molecular Weight: 114.35 (anhydrous); 150.38 (dihydrate)

Conversion Factor:
Not applicable

Physical State: Solid
Melting Point: 100 deg C (212 deg F) (loses 2 molecules of water to form anhydrous material) (5)
Boiling Point: Not available; probably decomposes.
Relative Density (Specific Gravity): Not available
Solubility in Water: Very soluble in cold (14 g/100 mL at 0 deg C) and hot water (24 g/100mL at 100 deg C) (anhydrous).(5)
Solubility in Other Liquids: Insoluble in ethanol and diethyl ether (5)
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available
pH Value: Practically neutral (1)
Vapour Density: Not applicable
Vapour Pressure: Not available; probably does not form vapour
Saturation Vapour Concentration: Not applicable
Evaporation Rate: Not applicable
Critical Temperature: Not applicable


Normally stable.

Hazardous Polymerization:
Does 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 ACIDS - can react vigorously and decompose magnesium formate to produce formic acid fumes.

Hazardous Decomposition Products:
None known

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

Corrosivity to Metals:
No information available


No relevant animal toxicity information was located.


Selected Bibliography:
(1) The Merck index: an encyclopedia of chemicals, drugs, and biologicals. 11th edition. Merck & Co., Inc., 1989. p. 892
(2) Hawley's condensed chemical dictionary. 12th edition. Van Nostrand Reinhold, 1993. p. 719
(3) Field, P. Explosibility assessment of industrial powders and dusts. Building Research Establishment, 1983
(4) Fire protection handbook. 17th edition. National Fire Protection Association, 1991. p. 2-332 to 2-333, 3-133 to 3-142
(5) CRC handbook of chemistry and physics. 64th edition. CRC Press, 1984. p. B-108
(6) 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: <>
(7) 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: <>
(8) Occupational Safety and Health Administration (OSHA). Metal and Metalloid Particulates in Workplace Atmospheres (Atomic Absorption). In: OSHA Analytical Methods Manual. Revision Date: Oct. 31, 2001. 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 class 1996-06-01
US transport 1996-06-01
Respiratory guidelines 1996-06-01
Bibliography 2005-03-24
Sampling/analysis 2005-03-24

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