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CHEMINFO Record Number: 232
CCOHS Chemical Name: Benzaldehyde

Benzoic aldehyde
Artificial almond oil
Synthetic oil of bitter almond
Benzene carboxaldehyde
Benzene carbaldehyde
Synthetic bitter almond oil

Chemical Name French: Benzaldéhyde
Chemical Name Spanish: Benzaldehido
CAS Registry Number: 100-52-7
Other CAS Registry Number(s): 8013-76-1
UN/NA Number(s): 1990
RTECS Number(s): CU4375000
EU EINECS/ELINCS Number: 202-860-4
Chemical Family: Aromatic aldehyde / araldehyde / benzene carboxaldehyde / phenylmethanal
Molecular Formula: C7-H6-O
Structural Formula: C6H5-CH(=O)


Appearance and Odour:
Colourless to yellow, oily liquid with an odour of bitter almonds.(1,3)

Odour Threshold:
5 ppb (100% recognition) (2)

Warning Properties:
GOOD - the odour threshold is 400 times less than the WEEL TWA.

Benzaldehyde is commercially available in two grades: pure benzaldehyde, which is suitable for most uses, and double-distilled benzaldehyde, which is mainly used in the pharmaceutical, perfume, and flavour industries and must be particularly pure and free from foreign odours.(3) Benzaldehyde may contain trace amounts of chlorine, water, benzoic acid, benzal chloride, benzyl alcohol, and/or nitrobenzene (3).

Uses and Occurrences:
Benzaldehyde is used in perfumes, soaps, foods, drinks, and other products; as a solvent for oils, resins, some cellulose ethers, cellulose acetate and cellulose nitrate; in the production of derivatives that are employed in the perfume and flavour industries (e.g. cinnamaldehyde, cinnamyl alcohol, cinnamic acid, benzylacetone and benzyl benzoate); in the production of triphenylmethane dyes and the acridine dye, benzoflavin; as an intermediate in the pharmaceutical industry (e.g. to make chloramphenicol, ephedrin, and ampicillin); as an intermediate to make benzoin, benzylamine, benzyl alcohol, mandelic acid, and 4-phenyl-3-buten-2-one (benzylideneacetone); in photochemistry; as a corrosion inhibitor and dyeing auxiliary; in the electroplating industry; and in the production of agricultural chemicals.(1,3)
Benzaldehyde exists in nature, occurring in combined and uncombined forms in many plants. The best known natural source of benzaldehyde is amygdalin. Benzaldehyde is also the main constituent of the essential oils obtained by pressing the kernels of peaches, cherries, apricots, and other fruits.(3)
Benzaldehyde is released to the environment in emissions from combustion processes such as gasoline and diesel engines, incinerators and wood burning. It is formed in the atmosphere through photochemical oxidation of toluene and other aromatic hydrocarbons.


Colourless to yellow, oily liquid with an odour of bitter almonds. COMBUSTIBLE LIQUID AND VAPOUR. Can be ignited relatively easily, for example, by contact with hot surfaces, due to the relatively low autoignition temperature. Undergoes autoxidation in air and is liable to self-heat. There is a risk of spontaneous combustion under these circumstances. May also ignite spontaneously if it is absorbed onto rags, cleaning cloths, clothing, sawdust, diatomaceous earth (kieselguhr), activated charcoal or other materials with large surface areas. Vapour is irritating to the upper respiratory tract. Central nervous system depressant. Vapour may cause headache, nausea, dizziness, drowsiness and confusion. EYE AND SKIN IRRITANT. May cause moderate to severe eye irritation. May cause moderate skin irritation. Prolonged contact with the skin may cause corrosive injury (burns and scarring).


Effects of Short-Term (Acute) Exposure

Benzaldehyde easily forms a vapour at room temperature. Exposure to 330 ppm is expected to produce intolerable irritation of the nose, throat and upper respiratory tract. Approximately 500 ppm is expected to cause signs of central nervous system depression such as fatigue, headache, nausea, dizziness and loss of coordination. Higher concentrations have produced more severe impairment of the central nervous system and death. These conclusions are based on evidence obtained from animal studies. No human information was located.

Skin Contact:
Benzaldehyde may be a moderate skin irritant, based on limited animal information. Prolonged contact may cause corrosive injury (burns and scarring). Application of 4% benzaldehyde in petrolatum, under cover in a 48-hour test, produced no irritation in two groups of human volunteers.(7, unconfirmed)
Benzaldehyde is not expected to be toxic if absorbed through the skin.

Eye Contact:
The liquid is probably a moderate or severe eye irritant, based on limited animal information. The vapour causes slight eye irritation.(33, unconfirmed) Exposure to 330 ppm is expected to cause intolerable eye irritation, based on animal information. No human information was located.

Benzaldehyde is not expected to be toxic if ingested, based on animal information. The only human information located is a case report, which is not available in English, of a woman who committed suicide by ingesting 50-60 mL. Based on limited information, it was estimated that an oral dose of 600-900 mg/kg would probably be lethal to humans in the absence of prompt treatment.(18) Irritation of the gastrointestinal tract and symptoms of central nervous system depression (as described for "Inhalation" above) are expected to occur. Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

Benzaldehyde is expected to cause skin irritation following repeated or prolonged contact. It is not possible to conclude that benzaldehyde is a skin sensitizer, based on the limited human and animal information available. No other information on the possible effects of long-term exposure to benzaldehyde was located.

Repeated or prolonged skin contact with benzaldehyde may irritate the skin and cause dermatitis (redness, swelling, scaling and itching).

Skin Sensitization:
There is insufficient information available to conclude that benzaldehyde is an occupational skin sensitizer.
In a maximization test, 4% benzaldehyde in petrolatum produced no sensitization reactions in 25 volunteers.(7,18-unconfirmed) In patch tests using 5% benzaldehyde in Vaseline(R), positive reactions occurred in 10/100 individuals.(7,18-unconfirmed) A case report describes a 19-year-old pastry maker who developed hives from working with pastry. The hives disappeared 1-2 hours after pastry contact. Patch tests indicated a positive reaction to benzaldehyde and cinnamic aldehyde (an ingredient in some pastries). There was no previous personal or family history of allergy. The positive reaction to benzaldehyde may have been a cross-reaction with cinnamic aldehyde.(34) Benzaldehyde has produced weak or no sensitization in animal tests.


No human information was located. In a 2-year feeding study with rats and mice, it was determined that benzaldehyde showed no evidence of carcinogenic activity in male or female rats. There was some evidence of carcinogenic activity (in the forestomach) in male and female mice.

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 information was located. An unconfirmed animal study, with insufficient details for evaluation, showed no developmental effects in rats.

Reproductive Toxicity:
No human information was located. An unconfirmed animal study, with insufficient details for evaluation, showed no reproductive effects in female rats.

No human or animal information was located. Results from short-term, in vitro tests do not indicate that benzaldehyde is mutagenic. A negative result was obtained with Drosophila (fruit flies).

Toxicologically Synergistic Materials:
No information was located.

Potential for Accumulation:
In rabbits and rats, benzaldehyde is metabolized primarily to hippuric acid, which is excreted in the urine.(35,36)
Benzaldehyde was found in milk samples from 8/8 lactating mothers.(37)


Remove source of contamination or move victim to fresh air. Obtain medical advice.

Skin Contact:
As quickly as possible, remove contaminated clothing, shoes and leather goods (e.g. watchbands, belts). Immediately flush with lukewarm, gently flowing water for 15-20 minutes. Immediately obtain medical attention. Double bag, seal, label and leave contaminated clothing, shoes and leather goods at the scene for safe disposal.

Eye Contact:
Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for 15-20 minutes, while holding the eyelid(s) open. If a contact lens is present, DO NOT delay irrigation or attempt to remove the lens. Take care not to rinse contaminated water into the unaffected eye or onto the face. Immediately obtain medical attention.

NEVER give anything by mouth if victim is rapidly losing consciousness, is unconscious or convulsing. Have victim rinse mouth thoroughly with water. DO NOT INDUCE VOMITING. If vomiting occurs naturally, have victim rinse mouth with water again. Immediately obtain medical attention.

First Aid Comments:
Provide general supportive measures (comfort, warmth, rest).
Consult a doctor and/or the nearest Poison Control Centre for all exposures except minor instances of inhalation or skin contact.
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:
63 deg C (145.4 deg F) (closed cup) (4,6)

Lower Flammable (Explosive) Limit (LFL/LEL):
1.4% (5,6)

Upper Flammable (Explosive) Limit (UFL/UEL):
7.8% (estimated) (5)

Autoignition (Ignition) Temperature:
192 deg C (377.6 deg F) (4,6)

Electrical Conductivity:
1.5 x 10(7) pS/m at 25 deg C (39,40)

Combustion and Thermal Decomposition Products:
Carbon monoxide, carbon dioxide and irritant and toxic gases.

Flammable Properties:

Specific Hazards Arising from the Chemical:
During a fire, irritating/toxic smoke and fumes may be generated. Closed containers may rupture violently and suddenly release large amounts of product when exposed to fire or excessive heat for a sufficient period of time.

Extinguishing Media:
Carbon dioxide, dry chemical powder, appropriate foam, water spray or fog. Water may be used to blanket fire.(6) "Multipurpose " alcohol-resistant foams are recommended for use on combustible polar or non-polar liquids, like benzaldehyde.(6) Foam manufacturers should be consulted for recommendations regarding types of foams and application rates.

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance or protected location. Approach fire from upwind to avoid hazardous benzaldehyde vapours and toxic decomposition products.
Water may be used to blanket fire. Water must be gently applied to the surface of the benzaldehyde liquid, preferably with a fine spray or nozzle.(6)
If possible, isolate materials not yet involved in the fire, and move containers from the fire area if this can be done without risk, and protect personnel. Closed containers may rupture violently when exposed to the heat of a fire. Therefore, fire-exposed containers or tanks should be cooled by application of hose streams. Application should begin as soon as possible (within the first several minutes) and should concentrate on any unwetted portions of the container. Apply water from the side and from a safe distance until well after the fire is out. Stay away from ends of tanks, involved in the fire, but be aware that flying material from ruptured tanks may travel in any direction. Withdraw immediately in case of rising sound from venting safety device or any discolouration of tank due to fire. Cooling should continue until well after the fire is out. If this is not possible, use unmanned monitor nozzles and immediately evacuate the area.
There is a risk of spontaneous combustion (self-ignition) if benzaldehyde is absorbed on materials, such as cleaning cloths, clothing and sawdust. Remove such materials from the vicinity.
If a leak or spill has not ignited, use water spray in large quantities to disperse the vapours and to protect personnel attempting to stop a leak. Water spray can be used to flush spills away from ignition sources. Dike fire control water for appropriate disposal. Solid streams of water may be ineffective and spread material.
For an advanced or massive fire in a large area, use unmanned hose holder or monitor nozzles; if this is not possible withdraw from fire area and allow fire to burn.
Tanks or drums should not be approached directly after they have been involved in a fire, until they have been completely cooled down.

Protection of Fire Fighters:
Benzaldehyde and its decomposition products are hazardous to health. Do not enter without wearing specialized equipment suitable for the situation. Firefighter's normal protective clothing (Bunker Gear) will not provide adequate protection. Chemical protective clothing (e.g. chemical splash suit) and positive pressure self-contained breathing apparatus (NIOSH approved or equivalent) may be necessary.


NFPA - Health: 1 - Exposure would cause significant irritation, but only minor residual injury.
NFPA - Flammability: 2 - Must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur.
NFPA - Instability: 0 - Normally stable, even under fire conditions, and not reactive with water.


Molecular Weight: 106.13

Conversion Factor:
1 ppm = 4.33 mg/m3; 1 mg/m3 = 0.23 ppm at 25 deg C (calculated)

Physical State: Liquid
Melting Point: -26 deg C (-14.8 deg F) (4,39); FREEZING POINT: reported as -55.6 deg C (-68.1 deg F) (3,42)
Boiling Point: 179 deg C (354.2 deg F) (3,4)
Relative Density (Specific Gravity): 1.045 at 20 deg C (42); 1.040 at 25 deg C (5,42) (water = 1)
Solubility in Water: Slightly soluble (300 mg/100 mL at 20 deg C (42,43); 654 mg/100 mL at 25 deg C (43))
Solubility in Other Liquids: Soluble in all proportions in many organic solvents, including ethanol and diethyl ether; very soluble in acetone.(3,44)
Coefficient of Oil/Water Distribution (Partition Coefficient): Log P(oct ) = 1.48 (experimental) (45)
pH Value: Not available
Acidity: Benzaldehyde is a weak acid.(51)
Dissociation Constant: pKa = 9.8 (calculated) (51)
Viscosity-Dynamic: 1.321 mPa.s (1.321 centipoises) at 25 deg C (4,42)
Surface Tension: 38.54 mN/m (38.54 dynes/cm) at 20 deg C; 38 mN/m (38 dynes/cm) at 25 deg C (calculated) (46)
Vapour Density: 3.66 (air = 1) (calculated)
Vapour Pressure: 0.161-0.169 kPa (1.21-1.27 mm Hg) at 25 deg C (43,47)
Saturation Vapour Concentration: 1600-1700 ppm (0.16-0.17%) at 25 deg C (calculated)
Evaporation Rate: Approximately 85 (diethyl ether = 1) (48, unconfirmed)
Henry's Law Constant: 2.70 Pa.m3/mol (cited as 2.67 X 10(-5) atm.m3/mol) at 25 deg C (49,50); log H = -2.96 (dimensionless constant; calculated)

Other Physical Properties:
DIELECTRIC CONSTANT: 17.85 at 20 deg C (39,42)


Unstable in air. Benzaldehyde undergoes autoxidation in air to form peroxybenzoic acid and benzoic acid. This process is accelerated by light (UV light).(3) Pure benzaldehyde is stable in the absence of air and sunlight .

Hazardous Polymerization:
Will not occur.

Self-Heating Materials:
Benzaldehyde reacts with oxygen in the air. The reaction is exothermic (heat is generated) and benzaldehyde is liable to self-heat. The reaction is accelerated by light. There is a risk of spontaneous combustion under these circumstances, because of the relatively low autoignition temperature.(3)

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.

AIR - benzaldehyde undergoes autoxidation in air to initially form peroxybenzoic acid, which catalyses the further oxidation to benzoic acid.(3,41,52,53)
STRONG OXIDIZING AGENTS (e.g. performic acid, potassium permanganate, nitric acid, chromium(VI) oxide) - react violently, with the risk of fire and explosion.(3,6,52)
STRONG BASES (e.g. sodium hydroxide or potassium hydroxide) or PHENOL - react violently with the risk of fire and explosion.(41)
HEAVY METAL SALTS (e.g. iron salts) - catalyze oxidation of benzaldehyde by atmospheric oxidation.(3)
STRONG REDUCING AGENTS (e.g. metal hydrides, like lithium aluminum hydride or sodium borohydride) - reaction may be vigorous or violent.(53)

Hazardous Decomposition Products:
Peroxybenzoic acid and benzoic acid.

Conditions to Avoid:
Air, light, heat, hot surfaces, e.g. hot pipes, sparks, open flames, other ignition sources.

Corrosivity to Metals:
Benzaldehyde is corrosive to gray and ductile cast iron (10% solution), and lead (all concentrations) at room temperature.(54,55) Pure benzaldehyde is not corrosive to cast iron. Some sources state that benzaldehyde attacks types 1010 and 1020 carbon steel (the corrosion rate is variable).(54,55) It is also reported to attack copper and brass.(4) Benzaldehyde does not attack most of the common metals, like stainless steels (e.g. types 301, 304, 316, 347 and 17-4PH), aluminum (e.g. types 3003 and Cast B-356), nickel and nickel-base alloys, like Monel, Hastelloy and Inconel, Carpenter 20Cb-3, bronze (unspecified), aluminum bronze, naval brass, tantalum, titanium and zirconium.(54,55)

Corrosivity to Non-Metals:
Benzaldehyde attacks plastics, like polyvinylidene chloride (Saran), chlorinated polyvinyl chloride (CPVC), polyvinyl chloride (PVC), nylon 610, 612 and 89, acrylonitrile-butadiene-styrene (ABS), cross-linked polyethylene, polyurethane (rigid), polysulfone, polymethacrylate (acrylic), polystyrene, bisphenol A-fumarate and isophthalic thermoset polyesters, and ethylene vinyl acetate; elastomers, like nitrile Buna-N (NBR), Viton A, chloroprene, styrene butadiene (SBR), isoprene, natural rubber, flexible polyvinyl chloride (PVC), fluorosilicone and polyurethane; and coatings, like coal tar epoxy, general purpose epoxy, phenolic, polyester and vinyls.(55,56,57) Benzaldehyde does not attack plastics, like Teflon, and other fluorocarbons, like ethylene tetrafluoroethylene (Tefzel), nylon 6, 11 and 66, ultra high molecular weight polyethylene (UHMWPE), polypropylene, polyethylene terephthalate and polybutylene terephthalate; and elastomers, like ethylene propylene, butyl rubber (isobutylene isopropylene), fluorocarbons, like Chemraz and Kalrez, and low-density polyethylene (LDPE).(55,56,57)


Lethal Concentration (rat): greater than 115 ppm (cited as greater than 500 mg/m3) (8, unconfirmed)
Lethal Concentration (mouse): greater than 115 ppm (cited as greater than 500 mg/m3) (8, unconfirmed)

LD50 (oral, rat): 1300 mg/kg (12)
LD50 (oral, guinea pig): 1000 mg/kg (12)
LD50 (oral, mouse): 800-1600 mg/kg (13)
LD50 (oral, male mouse): 27.79 mg/kg (administered 1:10 in sesame oil)* (14)
*Note: This value is questionable as it is much lower than other reported values and much lower than doses used in long-term ingestion experiments.

LD50 (dermal, guinea pig): greater than 21000 mg/kg (cited as greater than 20 cc/kg) (13)
LD50 (dermal, rabbit): greater than 1250 mg/kg (cited as greater than 1.25 gm/kg) (7, unconfirmed)

Eye Irritation:

The very limited information available suggests that benzaldehyde is a moderate or severe eye irritant.

In a study using only one rabbit, application of 1 drop of undiluted benzaldehyde caused immediate moderate redness (erythema), slight to moderate redness with swelling after 1 hour, and corneal opacity after 24 hours. Symptoms were reduced to slight redness after 48 hours and the rabbit died after 6 days.(13)

Skin Irritation:

The limited information available indicates that benzaldehyde is at least a moderate irritant and may be corrosive with prolonged contact.

In a limited study, application of 5250-21000 mg/kg (cited as 5-20 cc/kg) of undiluted benzaldehyde, under a cuff for 24 hours, caused moderate to gross swelling, redness, tissue death (eschars and necrosis) and scarring in 3 guinea pigs.(13) The degree of skin irritation was described as "moderate", although these effects are normally considered to represent corrosive skin damage. An unspecified quantity of undiluted benzaldehyde applied to intact or damaged skin for 24 hours, under a patch, was moderately irritating to rabbits.(7, unconfirmed) There are no further details available for evaluation.

Effects of Short-Term (Acute) Exposure:

Two strains of mice exposed to benzaldehyde (actual concentrations not reported) for 10 minutes, exhibited a dose-related decrease in respiratory rate. The RD50 (the dose resulting in a decrease in the respiratory rate by 50%) was calculated to be 333 and 394 ppm. The RD50 is an indicator of sensory irritation (irritation to the eyes and nose).(16) This concentration is expected to produce intolerable eye, nose and throat (sensory) irritation in humans. Rats were exposed to 0, 500, 750 or 1000 ppm benzaldehyde vapour for 14 days (6-hr/d). At 1000 ppm, 10/14 females and 1/14 males died during the first week, and animals developed abnormal gait and frequent seizures (indicating severe impairment of the central nervous system). Dose-related reduced body temperature, motor activity, and breathing and mild irritation of the eyes and nose were noted for all treatment groups. A significant decrease in body weight gain was noted in all treated males. At 1000 ppm, there was a significant decrease in red blood cells in females, increase in white blood cells in males and decrease in hemoglobin in both sexes. Liver weights of females were significantly increased at all doses. Relative liver weights were increased in males only at 500 ppm. At 500 and 1000 ppm, signs of mild irritation to the nasal epithelium (goblet cell metaplasia) were seen in males.(15) In a limited study, 3 rats exposed once to 1268 ppm (5.5 mg/L) for 6 hours showed eye blinking, nose rubbing, and increased respiration, and the extremities became pink (vasodilation).(13)

Rats were given 0, 100, 200, 400, 800, or 1600 mg/kg/day and mice were given 0, 200, 400, 800, 1600, or 3200 mg/kg benzaldehyde in corn oil 12 times over 16 days. All rats receiving 1600 mg/kg died on day 2 and 2/5 of each sex exposed to 800 mg/kg/day died before the end of the study. At 800 mg/kg/day, final average body weights were significantly reduced and increased excitability, tremors or inactivity were observed. No differences were noted in rats exposed to all other doses. All mice exposed to 1600 or 3200 mg/kg/day died by day 3. No signs of toxicity, including body weight changes and gross lesions, were observed in rats or mice in the other dose groups.(17,18)

Effects of Long-Term (Chronic) Exposure:

Rats were fed 0, 50, 100, 200, 400, or 800 mg/kg/day and mice were fed 0, 75, 150, 300, 600 or 1200 mg/kg/day benzaldehyde in corn oil for 13 weeks. In rats receiving 800 mg/kg/day, 6/10 males and 3/10 females died before the end of the study. In male rats, body weight gain was slightly reduced at 800 mg/kg/day. Hyperactivity, trembling and periodic inactivity were observed in males and females exposed to 800 mg/kg/day. Also at 800 mg/kg/day, decreased testes and thymus weights (males only), degeneration of the liver, necrosis of the liver (males only), degeneration and necrosis of brain tissues (cerebellum and hippocampus), moderate thickening of the epithelium in the forestomach, and degeneration of the kidneys were observed. Signs of irritation of the forestomach were observed in 2/10 males exposed to 400 mg/kg/day. No significant effects were observed with the lower dose exposures. In mice, 10/10 males and 1/10 females receiving 1200 mg/kg/day died. Body weight gain was reduced in males receiving 600 mg/kg/day and for females receiving 1200 mg/kg/day. Mild to moderate kidney degeneration was observed in all male mice exposed to 1200 mg/kg and one male mouse exposed to 600 mg/kg/day, but not in male mice exposed to lower doses or in female mice.(17,18) Rats fed benzaldehyde in the diet at 1000 ppm for 27-28 weeks or 10000 ppm for 16 weeks (EPA reports doses as 50 or 500 mg/kg/day) showed no effects on body weight, food intake, general condition, organ weights, or on blood or other tissues.(19)

Skin Sensitization:
Benzaldehyde is a non- to weak sensitizer.
In maximization tests (Magnusson-Kligman), 0/10 and 2/10 guinea pigs were sensitized when tested with benzaldehyde in paraffin oil.(20,21) In a "drop-on" test using guinea pigs, benzaldehyde was found to be a non-sensitizer.(13)

Respiratory Sensitization:
Benzaldehyde exposure reduced the severity of asthmatic responses in guinea pigs exposed to ovalbumin, a known sensitizer.
Male guinea pigs (8/group) were exposed to air only (group 1), air only with sensitization to ovalbumin (group 2), 500 ppb benzaldehyde (group 3) and 500 ppb benzaldehyde with sensitization to ovalbumin (group 4). The animals were then challenged to determine if exposure to benzaldehyde increased respiratory sensitization to ovalbumin. Only one sensitized benzaldehyde-exposed guinea pigs (group 4) showed a marked response to challenge with ovalbumin. A similar suppression of allergic response was observed in benzaldehyde-exposed animals (group 3). Animals exposed to this low concentration of benzaldehyde did show signs of respiratory irritation.(38)

In a well-conducted study, it was determined that benzaldehyde showed no evidence of carcinogenic activity in male or female rats. There was some evidence of carcinogenic activity (as evidenced by increased incidences of squamous cell papillomas and hyperplasia of the forestomach) in male and female mice.
Male and female rats and male mice were fed 0, 200 or 400 mg/kg/day, and female mice were fed 0, 300 or 600 mg/kg/day benzaldehyde in corn oil for 2 years. At 400 mg/kg/day, survival of male rats was significantly reduced. No other significant differences in survival rates were noted. A slight increase in mononuclear cell leukemia in male rats was not considered to be treatment related. A significant increase in thickening of the epithelium in the forestomach was observed in male mice exposed to 400 mg/kg/day and in female mice exposed to 200 or 400 mg/kg/day. The incidence of benign tumours of the forestomach epithelium (squamous cell papillomas) was significantly higher in exposed female mice.(18)

Teratogenicity, Embryotoxicity and/or Fetotoxicity:
No conclusions can be drawn based on the limited information available.
In a study, which is not available in English, 10 female rats were treated orally with 2 mg of benzaldehyde in oil (type not specified) every other day for 32 weeks. The approximate dose was 5 mg/kg/day. After 75 and 180 days, the females were mated with untreated males. No effects were observed on the maternal body weight, number of pups born, pup weight at birth, day 7 and 14, or on pup viability.(22, unconfirmed) There are insufficient details available to evaluate this study.

Reproductive Toxicity:
No conclusions can be drawn based on the limited information available.
In a study, which is not available in English, 10 female rats were treated orally with 2 mg of benzaldehyde in oil (type not specified) every other day for 32 weeks. The approximate dose was 5 mg/kg/day. After 75 and 180 days, the females were mated with untreated males. The number of pregnant rats was reduced in comparison to controls. However, no data or statistical analyses were presented.(22, unconfirmed) There are insufficient details available to evaluate this study.

The available information does not indicate that benzaldehyde is mutagenic.
Positive results (sister chromatid exchanges) were obtained in mammalian cells, with and without metabolic activation (23) and in cultured human lymphocytes (24). Tests for chromosome aberrations in cultured mammalian cells have given a positive result, with and without metabolic activation (25), a weak positive, with metabolic activation (26), and a negative result, with and without metabolic activation (23). Both positive (27) and negative (28) results were obtained for the induction of point mutations in cultured mammalian cells, in the absence of metabolic activation. Most studies with bacteria have shown negative results (gene mutations), with and without metabolic activation.(25,29,30) A positive result (gene mutation) was obtained in 1/13 strains bacteria tested in the presence of metabolic activation.(31)
Negative results were obtained in Drosophila (fruit flies).(32)


Selected Bibliography:
(1) Benzaldehyde. Hawley's condensed chemical dictionary. [CD-ROM]. 14th ed. Edited by R. J. Lewis, Sr. John Wiley and Sons, Inc., 2002
(2) Verschueren, K. Handbook of environmental data on organic chemicals. 4th ed. Vol. X. John Wiley and Sons, Inc., 2001. p. 28, 252-254
(3) Brühne, F., et al. Benzaldehyde. In: Ullmann's encyclopedia of industrial chemistry. 7th ed. John Wiley and Sons, 2005. Available at: <> {Subscription required}
(4) Opgrande, J.L., et al. Benzaldehyde. In: Kirk-Othmer encyclopedia of chemical technology. 4th ed. Vol. 4. John Wiley and Sons, 1992. p. 64-72
(5) Yaws, C.L. Handbook of chemical compound data for process safety: comprehensive safety and health-related data for hydrocarbons and organic chemicals: selected data for inorganic chemicals. Library of physico-chemical property data. Gulf Publishing Company, 1997. p. 15, 41, 68, 96
(6) Fire protection guide to hazardous materials. 13th ed. Edited by A. B. Spencer, et al. National Fire Protection Association, 2002. NFPA 325; NFPA 49; NFPA 491
(7) Benzaldehyde. In: Monographs on fragrance raw materials. A collection of monographs originally appearing in Food and Cosmetics Toxicology. Edited by D .L .J. Opdyke. Published on behalf of the Research Institute for Fragrance Materials. Pergamon Press, 1979. p. 115-120
(8) MDL Information Systems, Inc. Benzaldehyde. Last updated: 2002-07. In: Registry of Toxic Effects of Chemical Substances (RTECS(R)). [CD-ROM]. Canadian Centre for Occupational Health and Safety (CCOHS). Also available at: <> {Subscription required}
(9) Forsberg, K., et al. Quick selection guide to chemical protective clothing. 4th ed. Van Nostrand Reinhold, 2002
(11) European Economic Community. Commission Directive 93/72/EEC. Sept. 1, 1993
(12) Jenner, P.M., et al. Food flavourings and compounds of related structure. I. Acute oral toxicity. Food and Cosmetics Toxicology. Vol. 2 (1964). p. 327-343
(13) Letter from Eastman Kodak Company to USEPA submitting enclosed Material Safety Data Sheet, toxicity health and hazard summary and toxicity report on benzaldehyde with attachments. Date produced: Oct. 10, 1991. Eastman Kodak Co. EPA/OTS 86-920000051. NTIS/OTS0533617.
(14) Caprino, L., et al. Toxicological studies of photosensitizer agents and photodegradable polyolefins. European Journal of Toxicology. Vol. 9, no. 2 (1976). p. 99-103
(15) Laham, S., et al. Subacute inhalation toxicity of benzaldehyde in the Sprague-Dawley rat. American Industrial Hygiene Association Journal. Vol. 52, no. 12 (Dec. 1991). p. 503-510
(16) Steinhagen, W.H., et al. Sensory irritation structure-activity study of inhaled aldehydes in B6C3F1 and Swiss-Webster mice. Toxicology and Applied Pharmacology. Vol. 72, no. 3 (1984). p. 495-503
(17) Kluwe, W.M., et al. Encephalopathy in rats and nephropathy in rats and mice after subchronic oral exposure to benzaldehyde. Food and Chemical Toxicology. Vol. 21, no. 3 (1983). p. 245-250
(18) National Toxicology Program. NTP technical report on the toxicology and carcinogenesis studies of benzaldehyde (CAS No. 100-52-7) in F344/N rats and B6C3F mice (gavage studies). NTP TR 378. US Department of Health and Human Services, 1990
(19) Hagan, E.C., et al. Food flavourings and compounds of related structure. II. Subacute and chronic toxicity. Food and Cosmetics Toxicology. Vol. 5 (1967). p. 141-157
(20) Letter to USEPA regarding the enclosed evaluation summary on the Lever modification of the Magnusson-Kligman guinea pig maximization test with benzaldehyde w-attach (sanitized). Date produced: Nov. 26, 1991. EPA/OTS 86-920000281S. NTIS/OTS0533502.
(21) Letter submitting twenty one-page animal skin sensitization summary reports on cinnamic aldehyde, phenylacetaldehyde, benzaldehyde, and glutaraldehyde (sanitized). Date produced: Jan. 29, 1992. EPA/OTS 86-920000784S. NTIS/OTS0535611.
(22) International Programme on Chemical Safety. Benzyl acetate, benzyl alcohol, benzaldehyde and benzoic acid and its salts. In: WHO Food Additives Series: 37. Toxicological evaluation of certain food additives. Prepared by the Forth-sixth meeting of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). World Health Organization, 1996. p. 31-79
(23) Galloway, S.M., et al. Chromosome aberrations and sister chromatid exchanges in Chinese hamster ovary cells: Evaluation of 108 chemicals. Environmental and Molecular Mutagenesis. Vol. 10, suppl. 10 (1987). p. 1-175
(24) Jansson, T., et al. In vitro studies of the biological effects of cigarette smoke condensate. III. Induction of SCE by some phenolic and related constituents derived from cigarette smoke. A study of structure-activity relationships. Mutation Research. Vol. 206 (1988). p. 17-24
(25) Kasamaki, A.H., et al. Genotoxicity of flavoring agents. Mutation Research. Vol. 105, no. 6 (1982). p. 387-393
(26) Sofuni, T., et al. Mutagenicity tests on organic chemical contaminants in city water and related compounds. II. Chromosome aberration tests in cultured mammalian cells. Eisei Shikenjo Hokuku. Vol. 103 (1985). p. 64-75
(27) McGregor, D.B., et al. Responses of the L5178Y mouse lymphoma cell forward mutation assay. V:27 coded chemicals. Environmental and Molecular Mutagenesis. Vol. 17 (1991). p. 196-219
(28) Microbiological Associates Inc. Test for chemical induction of mutation in mammalian cells in culture the L5178Y TK+/- mouse lymphoma assay (final report) with cover letter dated 112691 (sanitized). Date produced: July 24, 1991. EPA/OTS 86-920000497S. NTIS/OTS0533786.
(29) Dillon, D., et al. The effectiveness of Salmonella strains TA100, TA102 and TA104 for detecting mutagenicity of some aldehydes and peroxides. Mutation Research. Vol. 13, no. 1 (Jan. 1998). p. 19-26
(30) Vamvakas, S., et al. Mutagenicity of benzyl S-haloalkyl and S-haloalkenyl sulfides in the Ames-test. Biochemical Pharmacology. Vol. 38, no. 6 (1989). p. 935-939
(31) Gee, P., et al. Comparison of responses of base-specific Salmonella tester strains with the traditional strains for identifying mutagens: the results of a validation study. Mutation Research. Vol. 412, no. 2 (Jan. 1998). p. 115-130
(32) Woodruff, R.C., et al. Chemical mutagenesis testing in Drosophila. V. Results of 53 coded compounds tested for the National Toxicology Program. Environmental and Molecular Mutagenesis. Vol. 7 (1985). p. 667-702
(33) Grant, W.M., et al. Toxicology of the eye. 4th ed. Charles C. Thomas, 1993. p. 208
(34) El Sayad, F., et al. Contact urticaria from cinnamic aldehyde and benzaldehyde in a confectioner. Contact Dermatitis. Vol. 31, no. 4 (1994). p. 272-273
(35) Laham, S., et al. Metabolism of benzaldehyde in New Zealand white rabbits. Chemosphere. Vol. 17, no. 3 (1988). p. 517-524
(36) Kutzman, R.S., et al. Biodistribution and excretion of [11C] benzaldehyde by the rat after two-minute inhalation exposures. Xenobiotica. Vol. 10, no. 4 (1980). p. 281-288
(37) Pellizzari, E.D., et al. Purgeable organic compounds in mother's milk. Bulletin of Environmental Contamination and Toxicology. Vol. 28, no. 3 (1974). p. 322-328
(38) Lacroix, G., et al. Decrease in ovalbumin-induced pulmonary allergic response by benzaldehyde but not acetaldehyde exposure in a guinea pig model. Journal of Toxicology and Environmental Health. Part A. Vol. 65 (2002). p. 995-1012
(39) Dean, J.A. Lange's handbook of chemistry. 15th ed. McGraw-Hill, Inc., 1999. p. 1.98, 5.90, 5.105, 5.139, 8.161
(40) Britton, LG. Using material data in static hazard assessment. Plant/Operations Progress. Vol. 11, no. 2 (Apr. 1992). p. 67
(41) Benzaldehyde. In: Chemical safety sheets: working safely with hazardous chemicals. Kluwer Academic Publishers, 1991. p. 94
(42) Riddick, J.A., et al. Organic solvents: physical properties and methods of purification. 4th ed. Techniques of organic chemistry. Vol. II. John Wiley and Sons, 1986. p. 332-333, 948-949
(43) Mackay, D. et al. Benzaldehyde. In: Physical-chemical properties and environmental fate handbook. (CD-ROM]. Chapman and Hall/CRCnetBase, 2000
(44) Handbook of chemistry and physics. [CD-ROM]. Edited by D.R. Lide. Chapman and Hall/CRCnetBASE, 1999
(45) Syracuse Research Corporation. Interactive LogKow (KowWin) Database Demo. Date unknown. Available at: <>
(46) Jasper, J.J. Surface tension of pure liquid compounds. In: Compilation of data of some 2200 pure liquid compounds. Journal of Physical and Chemical Reference Data. Vol. 1, no. 4 (1972). p. 849
(47) Ambrose, D. et al. Thermodynamic properties of organic oxygen compounds. 42. Physical and thermodynamic properties of benzaldehyde. Journal of Chemical Thermodynamics. Vol. 7 (1975). p. 1143-1157
(48) Benzaldehyde. In: Handbook of organic industrial solvents. Technical guide no. 6. 5th ed. Alliance of American Insurers, 1980. p. 64
(49) Syracuse Research Corporation. The Physical Properties Database (PHYSPROP). Interactive PhysProp Database Demo. Date unknown. Available at: <>
(50) Betterton E.A., et al. Henry's law constants of some environmentally important aldehydes. Environmental Science and Technology. Vol. 22 (1988). p. 1415-1418
(51) Benzaldehyde. In: IUCLID dataset. European Chemicals Bureau, Eurocommission, 2002. Available at: <>
(52) Bretherick's reactive chemical hazards database. [CD-ROM]. 6th ed. Version 3.0. Edited by P.G. Urben. Butterworth-Heinemann Ltd., 1999
(53) Streitweiser, A., et al. Introduction to organic chemistry. 4th ed. Revised printing. Prentice Hall, Inc., 1998. p. 410-414
(54) Pruett, K.M. Chemical resistance guide to metals and alloys: a guide to chemical resistance of metals and alloys. Compass Publications, 1995. p. 50-61
(55) Schweitzer, P.A. Corrosion resistance tables: metals, nonmetals, coatings, mortars, plastics, elastomers and linings, and fabrics. 4th ed. Part A, A-D. Marcel Dekker, Inc., 1995. p. 377-380
(56) Pruett, K.M. Chemical resistance guide for plastics: a guide to chemical resistance of engineering thermoplastics, fluoroplastics, fibers and thermoset resins. Compass Publications, 2000. p. 50-61
(57) Pruett, K.M. Chemical resistance guide for elastomers II: a guide to chemical resistance of rubber and elastomeric compounds. Compass Publications, 1994. p. C-38 to C-43
(58) National Institute for Occupational Safety and Health (NIOSH). Volatile Organic Compounds (screening). 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: 2007-04-12

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