TOLUENE

RECORD NUMBER: 202-17049

CHEMICAL FAMILY Aromatic hydrocarbon

MOLECULAR FORMULA: C7-H8

DESCRIPTION: Clear, colourless liquid with characteristic odour.

USAGE: Used to make chemicals (examples: benzene, toluene diisocyanate, benzoic acid), explosives, dyes and many other compounds. Used as a solvent for inks, paints, lacquers, resins, cleaners, glues and adhesives. Found in gasoline and aviation fuel.

Agricultural -

Industrial - Predominant usage as solvent

Domestic -

ROUTES OF EXPOSURE: Main route of exposure is through ambient air, particularly areas of heavy traffic and around filling stations, also from areas where solvents are used, near cigarettes and glue sniffing. (4)

TOLERANCE & EXPOSURE LEVELS: ODOUR THRESHOLD: Approximately 2 ppm

TIME-WEIGHTED AVERAGE (TLV-TWA) : 100 ppm (375 mg/m3)

HEALTH EFFECTS:

SHORT-TERM: Toluene is a fat solvent that causes a CNS dysfunction and the destruction of other tissues.(2) Inhalation of high vapour concentrations (greater than 200 ppm for 8 hours) affects the central nervous system. Symptoms include tiredness, muscle weakness, headache, dizziness, confusion, poor coordination, nausea and vomiting (1) Massive over-exposures have resulted in loss of consciousness and death. Liver injury has been reported in survivors of serious over-exposures.

Prolonged skin contact can cause dry, irritated skin.

Toluene vapour is poorly absorbed through the skin (1).

LONG-TERM: Workers exposed to between approximately 200 and 430 ppm toluene for periods from 17 to 33 years showed disturbances in memory, thinking ability, emotions and coordination. Increased levels of liver enzymes and enlarged livers were seen in some studies.(1)

Other chronic exposure effects are anaemia, anorexia, renal damage and toluene in the blood. (2)

REPRODUCTIVE EFFECTS: Limited evidence that exposed women may have an increased incidence of menstrual disorders. It is likely that absorbed toluene would be transferred from a pregnant woman to her unborn child. (1)

CARCINOGENICITY: No evidence to suggest that toluene is carcinogenic in humans. (1)

TERATOGENICITY AND EMBRYOTOXICITY :

MUTAGENICITY: Studies have suggested that toluene is not mutagenic.(1)

BIO-ACCUMULATION: Absorbed toluene is changed by the liver to hippuric acid and benzoylglucuronide which are excreted in the urine.

Toluene can be stored for several days in body fat with a biological half-life is 3 days. (1)

Detected in all 8 U.S. samples of breast milk from 4 urban areas. 250 whole blood samples: 100% positive with a range of 0.2ppb-38ppb with an av.1.5ppb. Detected in 91% in U.S. National Human Adipose Tissue Survey: 250ppb max.(4)

Suspected Effects:
Aplastic anaemia, cardiac sensitivity, cerebellar dystropy, hepatic damage, learning capacity decreased, mutagenisis, neural dystrophy, prenatal damage, phagocytic activity of leukocytes depressed, serum albumin depression, adrenal hypertrophy, plasma hydrocorticoid elevation. (2)

ANIMAL TOXICITY DATA: LD50 (oral, rat) 2500 mg/kg (5,000mg/kg)

LD50 (dermal, rabbit): 14000 mg/kg

LC50 (rat): 8000 ppm; 4-hr exposure

CARCINOGENICITY: No data available.(1)

REPRODUCTIVE EFFECTS: Rats, exposed to 266 ppm for 8 hours/day on days 1-21 of pregnancy had offspring which were slightly underweight. Bone formation was delayed Toluene did not cause birth defects (1).

MUTAGENICITY: Toluene was not mutagenic in short-term tests using three types of bacteria.(1) Chromosome abnormalities were reported in two early Russian studies using very high doses, but have not been reproduced in recent tests.(1)

Wildlife Data: Detected in U.S. oysters:3.4ppb, clams (2 sites) 11ppb and 18ppb. (4)

ENVIRONMENTAL EFFECTS:

Environmental Fate: When released into soil, toluene will evaporate from near surface soil and leach into groundwater. Biodegradation occurs in both soil and water but is slow particularly at high concentrations.

This may be due to toluene's toxicity to microorganisms. U.S.EPA database: 397 soil/sediment sample points: 17% positive with 5ppb median. (4)

When released into water, its removal depends on temperature, mixing conditions and microorganisms. It will not be significantly absorbed to sediment or bioconcentrate in aquatic organisms. U.S.Groundwater Supply Survey 1982: 466 drinking water supplies: 1.3% positive with 0.8ppb av. (4)

When released to atmosphere it will degrade by reaction with photochemically produced hydroxyl radicals or wash out with rain, with half life of 3hours to over one day.

Atmospheric Concentrations: Rural: 0.66ppb median (115 samples, 1978)

Urban: 11ppb median,max 85ppb (3195samples) (4)

Water MRL:

EPA DATA GAPS:

NOTE: Toluene is often contaminated with benzene.

** Disclaimer: These sheets are designed as summary information and as such are a guide only. The information is compiled from publicly available references which can be supplied on request.

References:

1.Canadian Centre of Occupational Health Database - CCINFO

2.Pesticides and Human Health, W.H.Hallenbeck&K.M.Cunningham-Burns School

of Public Health, Uni. of Illinois Chicago, Springer-Verlag 1985

3.Coffs Harbour Chemical Data Base 1991

4.Handbook of Environmental Fate and Exposure Data for Organic Chemicals,

Vol1 Large Production and Priority Pollutants., Philip H. Howard 1989

Lewis Publishers Inc. USA