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CHEMINFO Record Number: 673
CCOHS Chemical Name: Magnesium acetate

Acetic acid, magnesium salt
Magnesium diacetate
Acetate de magnesium

CAS Registry Number: 142-72-3
Other CAS Registry Number(s): 16674-78-5
RTECS Number(s): AI5600000
Chemical Family: Saturated aliphatic carboxylic acid salt / saturated aliphatic monocarboxylic acid salt / alkanoic acid salt / acetic acid salt / acetate / magnesium salt
Molecular Formula: C4-H6-Mg-O4
Structural Formula: (CH3-CO-O)2--.Mg++


Appearance and Odour:
White or colourless crystals; slight vinegar odour (acetic acid) (1,10) deliquescent (absorbs moisture from the air and forms wet solid or solution) (tetrahydrate).(10)

Odour Threshold:
Information not available

Warning Properties:
Insufficient information for evaluation

Magnesium acetate is one of the soluble salts of acetic acid. It has many similarities (properties and hazards) to other acetates. This record contains the available information specific for magnesium acetate, supplemented with general information on acetate salts which is applicable to magnesium acetate. It is available in both an anhydrous (CAS 142-72-3) and tetrahydrate (CAS 16674-78-5) (99 to 99.999%) form. Except where indicated, all information in this record applies to both forms of magnesium acetate. Low level impurities may include heavy metals such as iron, sulfates or sodium, potassium, calcium, barium or manganese compounds.

Uses and Occurrences:
Used in deodorants, disinfectants, antiseptics; as a dye fixative in textile printing.(1)


White or colourless deliquescent crystals, with a slight vinegar odour. POTENTIAL COMBUSTIBLE DUST HAZARD. Powdered material may form explosive dust-air mixtures. Essentially non-toxic.


Effects of Short-Term (Acute) Exposure

The available information indicates that magnesium acetate is practically non-toxic. High concentrations of dust may cause coughing and mild temporary irritation.

Skin Contact:
Dusts or mists may cause slight skin irritation based on information for related chemicals. It is probably not absorbed through the skin to a significant extent.

Eye Contact:
Dusts or mist may cause mild eye irritation based on information for related chemicals. Some tearing, blinking, and mild, temporary pain may occur as the solid material is rinsed from the eyes by tears.

Magnesium acetate is probably low in oral toxicity. Ingestion of small doses (less than 10 g) would probably not produce ill effects, based on animal information for related acetates and the use of acetic acid in diets.(2)

Effects of Long-Term (Chronic) Exposure

INHALATION: Magnesium acetate probably only causes minor, reversible effects on the lungs.(3) In general, long-term exposures to high concentrations of dusts may cause increased mucous flow in the nose and respiratory system airways.(4) This condition usually disappears after exposure stops.
SKIN: Prolonged or repeated contact may cause redness, drying and cracking of the skin (dermatitis).


No human or animal information available. Probably not carcinogenic.

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 human or animal information available. Probably not teratogenic or embryotoxic.

Reproductive Toxicity:
No human or animal information available. Probably not a reproductive hazard.

No human information is available. In one in-vitro mammalian cell test, magnesium acetate did not cause any mutagenic effect.(2)

Toxicologically Synergistic Materials:
Information not available

Potential for Accumulation:
Magnesium acetate can enter the body by inhalation or ingestion. It probably does not accumulate. Magnesium and acetate ions are normally found in the body. Magnesium ions are poorly and slowly absorbed. About one third of ingested magnesium ion is absorbed from the gastrointestinal tract. Magnesium ion is excreted principally in the urine, with some in the feces. The acetate ion is rapidly and completely metabolized.


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

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

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 particle/dust does not dislodge, flush with lukewarm, gently flowing water for 5 minutes or until particle/dust is removed, while holding eyelid(s) open. If irritation persists, obtain medical attention. DO NOT attempt to manually remove anything stuck to eye(s).

If irritation or discomfort occur, obtain medical advice immediately.

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


Flash Point:
Not applicable. Magnesium acetate 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:
Not sensitive. Stable material.

Combustion and Thermal Decomposition Products:
Carbon monoxide and carbon dioxide.(8)

Flammable Properties:

Extinguishing Media:
Carbon dioxide, dry chemical powder, alcohol foam, polymer foam, water fog or mist.(8)

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance or a protected location. Approach fire from upwind to avoid toxic decomposition products. Avoid generating dust to minimize risk of explosion.
Water spray, fog or foam can be used to extinguish fires involving magnesium acetate. Water or foam may cause frothing. However, a water spray or fog that is gently applied to the surface of the liquid, preferably with a fine spray or fog nozzle, will cause frothing that will blanket and extinguish the fire. In addition, 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.
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: 142.4 (anhydrous); 214.5 (tetrahydrate)

Conversion Factor:
Not applicable

Physical State: Solid
Melting Point: 323 deg C (613 deg F), decomposes (anhydrous); 80 deg C (176 deg F) (tetrahydrate).(11)
Boiling Point: Not applicable (does not form vapour).
Relative Density (Specific Gravity): 1.42 (anhydrous); 1.454 (tetrahydrate) (water = 1) (11)
Solubility in Water: Very soluble in cold and hot water
Solubility in Other Liquids: Very soluble in ethanol (tetrahydrate); moderately soluble in methanol (anhydrous).(11)
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available
pH Value: Aqueous solution is neutral, or slightly acid (10)
Vapour Density: Not applicable
Vapour Pressure: Zero (does not form a vapour)
Saturation Vapour Concentration: Not applicable
Evaporation Rate: Not applicable
Critical Temperature: Not applicable


Normally stable.

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 ACIDS - may react vigorously and decompose magnesium acetate to produce acetic acid fumes.

Hazardous Decomposition Products:
None known

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

Corrosivity to Metals:
Information not available.


Standard animal toxicity values are not available.


Selected Bibliography:
(1) Hawley's condensed chemical dictionary. 12th edition. Van Nostrand Reinhold, 1993. p. 717-718
(2) Toxicological evaluation of some food additives including anticaking agents, antimicrobials, antioxidants, emulsifiers and thickening agents. (WHO Food Additives Series, No. 5). World Health Organization, 1974. p. 31-33
(3) Documentation of the threshold limit values and biological exposure indices. 5th edition. ACGIH, 1986. p. 445
(4) Wright, G.W. The pulmonary effects of inhaled inorganic dust. In: Patty's industrial hygiene and toxicology. 4th edition. Vol. 1, Part A. John Wiley & Sons, 1994. p. 307-309
(5) RTECS record for acetic acid, magnesium salt. Date of last update 9404
(6) Grossel, S.S. Safety considerations in conveying of bulk solids and powders. Journal of Loss Prevention in the Process Industries. Vol. 1 (April, 1988). p. 62-74
(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. Vol. 1. Sigma-Aldrich, 1988. p. 2177D
(9) Schwab, R.F. Dusts. In: Fire protection handbook. Edited by A.E. Cote. 18th edition. National Fire Protection Association, 1991. p. 4-174 to 4-181
(10) The Merck index: an encyclopedia of chemicals, drugs, and biologicals. 11th edition. Merck & Co., Inc., 1989. p. 891 (11) CRC handbook of chemistry and physics. 64th edition. CRC Press, Inc., 1983. p. B-107
(11) 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:
(12) 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: <>
(13) 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: 1995-01-23

Revision Indicators:
US Transport 1996-06-01
EU class 1996-06-01
Resistance of materials 1998-06-01
Bibliography 2005-03-14
Sampling/analysis 2005-03-14
LFL/LEL 2006-10-04
UFL/UEL 2006-10-04
Emergency overview 2006-10-04

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