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CHEMINFO Record Number: 694
CCOHS Chemical Name: Sorbic acid

Acetic acid, (2-butenylidene)
Acetic acid, crotylidene
Hexadienic acid
Hexadienoic acid
2,4-Hexadienoic acid
trans,trans-2,4-Hexadienoic acid
1,3-Pentadiene-1-carboxylic acid
2-Propenylacrylic acid
trans,trans-Sorbic acid

Chemical Name French: Acide sorbique
CAS Registry Number: 110-44-1
Other CAS Registry Number(s): 22500-92-1
RTECS Number(s): WG2100000
EU EINECS/ELINCS Number: 203-768-7
Chemical Family: Unsaturated aliphatic carboxylic acid / unsaturated aliphatic monocarboxylic acid / unsaturated fatty acid / polyunsaturated fatty acid / alkenoic acid / alkadienoic acid
Molecular Formula: C6-H8-O2
Structural Formula: CH3-CH=CH-CH=CH-C(=O)-OH


Appearance and Odour:
White crystalline solid, with a weak characteristic odour.(3,8,15)

Odour Threshold:
No information was located

Warning Properties:
Information not available for evaluation.

Sorbic acid is one of several chemical forms of 2,4-hexadienoic acid. It is commercially available in highly pure (99% and greater) due to its use in food products. Possible impurities may include aldehydes, arsenic, heavy metals (e.g. lead) and other chemical forms (isomers) of 2,4-hexadienoic acid.(8,15)

Uses and Occurrences:
Sorbic acid and its potassium salt, commonly called sorbates, are used almost exclusively as preservatives in foods, beverages, pet foods, commercial animal feeds, tobacco, cosmetics, inks and glues and in packing materials for these substances. Also used as an additive in alkyd coatings, drying oils, rubber and as an intermediate for plasticizers and lubricants.(8,15)


White crystalline solid, with a weak characteristic odour. Can burn if strongly heated. COMBUSTIBLE DUST. Can form explosive dust-air mixtures. Can cause redness, swelling and itching (non-allergic hives) at the point of skin contact.


Effects of Short-Term (Acute) Exposure

Airborne sorbic acid dust probably causes little harmful effect on the lung or elsewhere in the body, based on its low toxicity by other routes of exposure and its low water solubility. In general, high concentrations of dust may cause coughing and mild, temporary irritation. There is no human or animal information available.

Skin Contact:
Sorbic acid is probably a very mild skin irritant based on human and animal information. Sorbic acid can cause redness and swelling with itching (non-immunological contact urticaria or hives) in most people at the site of application. Individuals can react without having been previously exposed to sorbic acid. The strength of the reaction is dose dependent, ranging from slight redness to extensive redness and swelling with tingling, burning or itching.(1) Apart from the contact urticaria reaction, sorbic acid dusts and solutions are probably not irritating or are only slightly irritating.
Temporary redness and swelling were observed following application of sorbic acid concentrations as low as 0.1% (in a 2-isopropanol-water mixture) to the skin of 15-17 volunteers. Reactions were most intense on the face, but were also observed on the back, forearm and shoulder areas.(2) Some redness was observed in 19.8-67.4% of 91 volunteers and swelling was observed in 0-9%, following 20 minute application of concentrations of 0.1-10% sorbic acid in petrolatum to the skin.(3) In another test, creams and ointments containing sorbic acid caused redness, slight itching and, sometimes, slight swelling on the face in about half the people tested.(4) In a study using 2.5% sorbic acid in petrolatum, the reaction was found to occur within 45 minutes of application and disappeared within two hours.(4)

Eye Contact:
Dusts, solids or mists from solutions are probably mildly irritating, based on limited human and animal information. Up to 10% sorbic acid in petrolatum was practically non-irritating in an animal test. One report, which provides few details, indicates that corneal injury has occurred following an occupational exposure to sorbic acid. Healing occurred within 48 hours.(5)

Sorbic acid is used in low concentrations, as a food additive in many common foods. It has a low oral toxicity, based on animal information. Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

SKIN CONTACT: Repeated or prolonged contact with sorbic acid or products containing sorbic acid may cause irritation, based on animal information.

SKIN SENSITIZATION: Sorbic acid was non-sensitizing or did not produce a statistically significant incidence of sensitization in two studies using human volunteers.(3) Sorbic acid was also non-sensitizing in an animal study.


There is no human information available. In one mouse study, sorbic acid caused liver tumours at very high dietary levels. Five other mouse and rat ingestion studies were negative.

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:
There is no human or animal information available.

Reproductive Toxicity:
There is no human information available. Sorbic acid did not cause adverse effects in two animal studies.

There is no human information available. A negative result has been reported in a mouse in vivo study. Both positive and negative results have been reported in tests using bacteria and cultured mammalian cells.

Toxicologically Synergistic Materials:
A synergistic mutagenic effect (chromosomal abnormalities and spindle disturbances) of sorbic acid and sorbic acid nitrite was observed in mice when these two chemicals were ingested together.(6)

Potential for Accumulation:
Sorbic acid does not accumulate in the body. It is mostly metabolized to carbon dioxide, which is exhaled, and water. Traces (0.1% of dose) are converted into trans,trans-muconic acid.(7,8)


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

Skin Contact:
Remove contaminated clothing, shoes and leather goods (e.g. watchbands, belts). Gently blot or brush away excess chemical quickly. Wash gently and thoroughly with water and non-abrasive soap for 5 minutes, or until the chemical is removed. If hives develop, obtain medical advice immediately. Completely decontaminate clothing, shoes and leather goods before re-use.

Eye Contact:
Do not allow victim to rub eye(s). Let the eye(s) water naturally for a few minutes or until the chemical is removed. If 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).

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:
126-130 deg C (259-266 deg F) (method not specified) (8)

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

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

Autoignition (Ignition) Temperature:
Not available

Sensitivity to Mechanical Impact:
Not sensitive. Stable material.

Combustion and Thermal Decomposition Products:
Carbon monoxide, carbon dioxide and other toxic constituents. Incomplete combustion may also produce acrid smoke and irritating fumes.

Flammable Properties:

Specific Hazards Arising from the Chemical:
During a fire, irritating/toxic gases and fumes may be generated.

Extinguishing Media:
Carbon dioxide, dry chemical powder, alcohol foam, polymer foam, water spray or foam.

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.
Water or foam may cause frothing. The frothing may be violent and could endanger personnel close to the fire. However, a water spray or fog that is carefully applied to the surface of the burning material, preferably with a fine spray or fog nozzle, will cause frothing that will blanket and extinguish the fire. In addition, water spray or fog can be used to prevent dust formation, absorb heat, keep containers cool and protect exposed material. Water spray may be used to flush spills away from ignition sources. Solid streams of water may be ineffective and spread material.
The decomposition products of sorbic acid may be hazardous to health. Firefighters may enter the area if positive-pressure self-contained breathing apparatus (MSHA/NIOSH approved or equivalent) and full Bunker Gear is worn.


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


Molecular Weight: 112.13

Conversion Factor:
Not applicable

Physical State: Solid
Melting Point: 134.5 deg C (274 deg F) (8,19); begins to sublime above 60 deg C (140 deg F) (15)
Boiling Point: 228 deg C (442.4 deg F) at 101.3 kPa (8); also reported to decompose (15)
Relative Density (Specific Gravity): 1.204 at 19 deg C (water = 1) (8)
Solubility in Water: Slightly soluble (150 mg/100 g at 20 deg C) (8)
Solubility in Other Liquids: Soluble in absolute ethanol, methanol, isopropanol, butanol, acetone, 1,4- dioxane and glacial acetic acid; moderately soluble in 60 wt% ethanol, diethyl ether, benzene, propylene glycol and carbon tetrachloride; slightly soluble in cyclohexane, glycerol and oils.(8,19)
Coefficient of Oil/Water Distribution (Partition Coefficient): Log P = 0.96; 1.70 (calculated) (20)
pH Value: 3.3 (saturated solution (0.15%) at 20 deg C) (calculated)
Vapour Density: 3.87 (air = 1) (7)
Vapour Pressure: Less than 0.001 kPa at 20 deg C; 1.3 kPa (9.75 mm Hg) at 130 deg C (8)
Saturation Vapour Concentration: Very low at normal temperatures.
Evaporation Rate: Very low at normal temperatures.
Critical Temperature: Not available

Other Physical Properties:
ACIDITY: Weak acid; pKa = 4.76 (Ka = 1.73 x 10(-5)) at 25 deg C (8,15)


Normally stable. Reported to decompose at the boiling point (228 deg C).(15) Pure crystalline sorbic acid is resistant to air oxidation. The presence of impurities may cause decomposition in light or air (oxygen).(15)

Hazardous Polymerization:
Polymerization of sorbic acid is catalyzed by free radicals. Copolymers can be formed with acrylonitrile, butadiene, isoprene, acrylates, piperylene, styrene and polyethylene.(8)

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.

CELLULOSIC MATERIALS (e.g. paper, cloth) - materials soaked with sorbates may ignite spontaneously.(7)
STRONG OXIDIZING AGENTS (e.g. perchlorates, peroxides, molecular oxygen) - may react vigorously or violently, Increased risk of fire.(7,8)
STRONG BASES (including alkalis such as sodium hydroxide) - react vigorously.

Hazardous Decomposition Products:
Information not available

Conditions to Avoid:
Generation of dust, heat, flames, sparks, build-up of static electricity and other ignition sources.

Corrosivity to Metals:
Not corrosive to types 304 and 316 stainless steels at 88 deg C (as a water slurry).(21) The ability of sorbic acid to polymerize, particularly on metallic surfaces, has been used to explain its corrosion inhibition for steel, iron and nickel.(8)


LD50 (oral, rat): 3200 mg/kg (9, unconfirmed); 7360 mg/kg (10); 10500 mg/kg (11)
LD50 (oral, mouse): 3200-6400 mg/kg (9, unconfirmed); greater than 8000 mg/kg (3)

Eye Irritation:

Practically no irritation was observed in rabbits in a modified Draize test (scored 0.7 to 2/110) following application of 1-10% sorbic acid in petrolatum.(3)

Skin Irritation:

Practically no irritation (scored 0-0.5/8) was observed in rabbits in a modified Draize test using 1, 5, and 10% sorbic acid (in petrolatum). In contrast, severe irritation was reported in in rabbits in another study (details of this test are not available in English).(9, unconfirmed) In a test designed to evaluate the potential of chemicals to cause non- immunological contact urticaria (hives), immediate redness and swelling was observed following application of 0.2-10% sorbic acid to guinea pig ear lobes. However, no irritation was observed following similar application to the back, abdomen or flank.(1)

Effects of Short-Term (Acute) Exposure:

No harmful effects were observed in rats following administration of 110 mg/kg/day (reported as 1.0 mmol/kg/day) for 3 days. A reduced rate of growth and microscopically visible injury to the liver, kidney, spleen or testis was observed in at least 1 of 10 animals following ingestion of 48 mg/kg/day for 30 days.(10) No conclusions can be drawn from this report because the data was not statistically evaluated.

Effects of Long-Term (Chronic) Exposure:

Skin Contact:
No irritation or harmful effects were observed in rats following dermal application of 5% sorbic acid in petrolatum-lanolin paste for 2 minutes/day, followed by washing with water, for 3 weeks. No harmful effects except for slight to moderate redness and swelling, slight lack of skin tone and slight shedding were observed following application of 0.5% sorbic acid (pH unspecified) for 4 weeks to either damaged or undamaged skin.(3)

In a number of studies, rats fed 50-5000 mg/kg/day sorbic acid in the diet for up to 2 years showed either no adverse effects or only slight liver, kidney and/or thyroid enlargement and/or slightly decreased weight gains.(3,9,12)

Skin Sensitization:
No statistically significant positive reaction was observed in guinea pigs following application of 0.1% sorbic acid in saline (optimization method).(3)

No carcinogenic effects were seen in five studies using rats or mice fed diets containing up to 10% sorbic acid for up to 2 years. In one of these studies, rats and mice were fed 1.2% sorbic acid which had been deliberately contaminated with 1000 ppm parasorbic acid, a possible contaminant in sorbic acid which is a suspected carcinogen. Liver tumours were reported in one study using mice fed very high concentrations (up to 15%) sorbic acid for 88 weeks.(3)

Reproductive Toxicity:
No harmful effects on reproduction were observed in rats following ingestion of 10% in the diet for up to 120 days or following ingestion of up to 5% in the diet (up to 2500 mg/kg/day) for 1000 days.(3)

A negative result was obtained in a mouse in vivo test (chromosomal abnormalities in bone marrow cells).(6)
Negative results have been obtained in several tests using bacterial cells.(3,13) Both weakly positive and negative results were obtained in tests using cultured mammalian cells.(3,14)


Selected Bibliography:
(1) Lahti, A., et al. An animal model for nonimmunologic contact urticaria. Toxicology and Applied Pharmacology. Vol. 76, no. 2 (Nov. 1984). p. 219-224
(2) Soschin, D., et al. Sorbic acid-induced erythema and edema. Journal of the American Academy of Dermatology. Vol. 14, no. 2, part 1 (Feb. 1986). p. 234-241
(3) Final report on the safety assessment of sorbic acid and potassium sorbate. Journal of the American College of Toxicology. Vol. 7, no. 6 (1988). p. 837-872
(4) Fisher, A.A. Contact urticaria due to occupational exposures. In: Occupational skin disease. 2nd ed. Edited by R.M. Adams. W.B. Saunders Company, 1990. p. 113-126
(5) McLaughlin, R.S. Chemical burns of the human cornea. American Journal of Ophthalmology. Vol. 29, no. 11 (Nov. 1946). p. 1355-1362
(6) Banerjee, T.S., et al. Effects of sorbic acid and sorbic acid-nitrate in vivo on bone marrow chromosomes of mice. Toxicology Letters. Vol. 31 (1986). p. 101-106
(7) HSDB record for sorbic acid. Last revision date: 96/01/19
(8) Dorko, C.L. et al. Sorbic acid. In: Kirk-Othmer encyclopedia of chemical technology. 4th ed. Vol. 22. John Wiley and Sons, 1997. p. 571-590
(9) Katz, G.V., et al. Aliphatic carboxylic acids. In: Patty's industrial hygiene and toxicology. 4th ed. Edited by G.D. Clayton et al. Vol. II. Toxicology. Part E. John Wiley and Sons, 1994. p. 3596, 3599, 3614-3617
(10) Smyth, Jr., H.F., et al. Further experience with the range finding test in the industrial toxicology laboratory. Journal of Industrial Hygiene and Toxicology. Vol. 30, no. 1 (1948). p. 63-68
(11) Sorbic acid and its calcium, potassium and sodium salts. In: 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. 121-129
(12) Hendy, R.J., et al. Long-term toxicity studies of sorbic acid in mice. Food and Cosmetics Toxicology. Vol. 14 (1976). p. 381-386
(13) Ishidate, Jr., M., et al. Primary mutagenicity screening of food additives currently used in Japan. Food and Chemical Toxicology. Vol. 22, no. 8 (1984). p. 623-636
(14) Hasegawa, M.M., et al. Effects of sorbic acid and its salts on chromosome aberrations, sister chromatid exchanges and gene mutations in cultured Chinese Hamster cells. Food and Chemical Toxicology. Vol. 22, no. 7 (1984). p. 501-507
(15) Luck, E. Sorbic acid. In: Ullmann's encyclopedia of industrial chemistry. 5th revised ed. Vol. A 24. VCH Verlagsgesellschaft, 1993. p. 507-513
(16) Field, P. Dust explosions. Elsevier Scientific Publishing Company, 1982. p. 217
(17) Grossel, S.S. Safety considerations in conveying of bulk solids and powders. Journal of Loss Prevention in the Process Industries. Vol. 1 (Apr. 1988) p. 62-74
(18) Schwab, R.F. Dusts. In: Fire protection handbook. Edited by G.P. McKinnon. 15th ed. National Fire Protection Association, 1981. p. 4-84 to 4-97
(19) Dean, J.A. Lange's handbook of chemistry. 14th ed. McGraw-Hill, Inc., 1992. p. 1.220, 8.47
(20) Leo A., et al. Partition coefficients and their uses. Chemical reviews. Vol. 71, no. 6 (Dec. 1971). p. 573
(21) Elder, G.B. Materials of construction for organic acids. In: Process industries corrosion: the theory and practice. Edited by B.J. Moniz, et al. National Association of Corrosion Engineers, 1986. p. 287-296

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: 1998-01-27

Revision Indicators:
Chemical Name French 2003-05-13
Short-term skin contact 2006-03-12
Short-term eye contact 2006-03-12
LFL/LEL 2006-10-05
UFL/UEL 2006-10-05

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