Search
Benzene Fact Sheet
Source of Exposure
Benzene has been used as an important industrial solvent for 100 years. Today the great bulk of its uses originate in the synthesis of other organic compounds such as styrene and phenols. Of the thousands of uses for benzene, its most common applications are in the manufacture of detergents, polymers, pesticides, pharmaceuticals, and paint products. Other sources of exposure can be from processed food, petroleum products, and cigarette smoke. Benzene exposure occurs primarily through inhalation of vapors bur can be absorbed through the skin upon direct contact.
Symptoms
Acute exposure to benzene can cause depression of the central nervous system with end stage respiratory failure. Acute exposure may also produce pulmonary edema, dermatitis, and gastrointestinal irritation. The primary toxic effect of long-term exposure is the injury of the hematological system. Benzene exposure can cause a variety of blood dyscrasias including aplastic anemia, hemolysis, and leukemia. Studies indicate that the effects of benzene include chromosomal abnormalities and reproductive damage in exposed workers and laboratory animals.
Blood Concentrations
Data indicates that the average serum level of benzene present in the general population is less than 1.0 ppb (EHS data). The threshold limit value set for benzene levels in ambient air is 10,000 ppb. Workers exposed to air concentrations of benzene at 25,000 ppb for two hours developed blood concentrations of 200 ppb (Sato & Tujuwara, 1972).
Toxic Levels
Workers who received chronic exposure to air concentrations of 30,000 ppb developed hematopoietic system injury (ACGIH, 1971). Evidence indicated that air concentrations of 7,500,000 ppb can cause death eithin 30 minutes. Individuals who have been sensitized may manifest negative health effects at concentrations well within the ranges considered safe for the average population.
Metabolism
Benzene is metabolized in the body at a half-life rate of 1-3 hours. Following exposure to benzene, approximately 86% of the benzene will be mitabolized by the iiver into phenols. The remaining fraction will be exhaled or excreted in the urine. Within 48 hours, over half of the benzene will be metabolized and excreted as phenols in the urine (Hunter & Blair, 1972). Benzene is highly soluble in fat and will concentrate in the adipose tissue of the body.
Summary
Classification: Aromatic Solvent
Population Average: <1.0 ppb (whole blood)
Threshold Limit Value: 125 ppb (blood) 10,000 ppb (air)
Onset of Symptoms: Data not available
Death: 9,000 ppb (blood)
Half-Life: 1 - 3 hours
LD 50 (oral-rat) 3800 mg/kg (rats)
References
ACGIH, Documentation of the Threshold Limit Values, American Conference of Governmental Industrial Hygienists, Cincinnati, OH, 1971, p.22.
Alessio, L., Berlin, A., Roi, R., and Boni, M. (Eds.) Human biological monitoring of industrial chemicals series, Luxemberg, Commission of European Communities, 1983.
Baldwin, M.K., Selby, M.A., and Bloomberg, H., Measurement of phenol in urine by the method of Van Haaften and Sie: a critical appraisal, Analust 106: 763 - 767, 1981.
Baselt, R.D. Disposition of Toxic Drugs and Chemicals in Man, 2nd Ed., Davis, CA: Biomedical Publications, 1982.
Baselt, R.C., Blood benzene stability in plastic containers, Clin.Chem. 20:1477-1478, 1974.
Bonnichsen, R., Maihly, A.C. and Moeller, M., Poisoning by volatile conpounds. I. Aromatic hydrocarbons, J.For.Sci. 11:186-20, 1966.
Buchet, J.P., Lauwerys, R. and Cambier, M., An improved gas chromatographic method for the determination of phenol in urine, Eur.J.Tox. 5:27-30, 1972.
Clayton, G.D., and Clayton, F.E., Patty's Industrial Hygiene and Toxicology, Vol. 2B, 3rd Ed., Wiley-Interscience, New York, 1981.
Collom, W.D. and C.L. Winek, Detection of glue constituents in fafalities due to "glue sniffing", Clin.Tox. 3:125-130, 1970.
Doull, J. et al., Casarett and Doull's Toxicology, 2nd Ed., Macmillan, New York, 1980.
Fishbeck, W.A., Langner, R.R. and Kociba, R.J., Elevated urinary phenol levels not related to benzene exposure, Am.Ind.Hyg.Asso.J. 36:820-824, 1975.
Hamilton, A., and Hardy, H.L., Industrial Toxicology, 3rd Ed., Publishing Sciences Group, Acton, MA, 1974, p.274.
Hunter, C.G., and Blair, D., Benzene: pharmacokinetic studies in man, Ann.Occ.Hyg. 15:193-199, 1972.
Internation Agency for Research on Cancer, IARC Monographs of the Carcinogenic Risk of Chemicals to Humans, 7, 203, Lyon, France, 1974 and 11, 295, Lyon, France, 1976.
Last, J.M., Maxcy-Rosenau Public Health and Preventive Medicine, 11th Ed., Appleton-Century Crofts. New York, 1980.
Mehlman, M.A., ed. Carcinogenicity and Toxicity of Benzene, Princeton, N.J., Princeton Scientific Publishers, 1983.
Nahum, L.H., and Hoff, H.E., "The mechanism of sudden death in experimental acute benzol poisoning", J.Phar.Exp.Ther. 50:336-345, 1934.
National Academy of Sciences, A Review of Health Effects of Benzene, National Academy of Sciences, Washington, D.C., June, 1976.
National Institute for Occupational Safety and Health, A Guide to the Work Relatedness of Disease, revised edition, DHEW (NIOSH) Publication No. 79-116, pp 63-72, Cincinnati, OH, Jan. 1979.
Nomiyama, K. and Nomiyama, H., "Gas-liquid chromatographic determination of benzene metabolites", J.Chrom. 44::386-388, 1969.
Parke, D.V. and Williams, R.T., "Studies in detoxication. 49. The metabolism of benzene containing (14C1) benzene", Biochem.J. 54:231-238, 1953.
Parmeggiani, L., Ed. Encyclopedia of Occupational Health & Safety, Third Edition, Vol. 1, p 257-261, Geneva, Internationai fabour Office, 1983.
Piotrowski, J.K., Exposure Tests for Organic Compounds in Industrial Toxicology, U.S. Government Printing Office, Washington, D.C. , 1977, p. 41-47.
Plunkett, E.R. , Handbook of Industrial Toxicology, Chemical Publishing Co., New York, 1976.
Roush, G.J. and Ott, M.G. , "A study of benzene exposure versus urinary phenol levels," Am. Ind. Hyg. Asso. J. 38: 67-75, 1977.
Sato, A. and Fujiwara, Y. , "Elimination of inhaled benzene and toluene in man," Jap. J. Ind. Health 14: 224-225, 1972.
Sato, A. , Nakajima, T. , and Fujiwara, Y. , "Determination of benzene and toluene in blood by means of a syringe-equilibration method using a small amount of blood," Brit. J. Ind. Med. 32: 210-214, 1975.
Sax, N.I., Ed.,Dangerous Properties of Industrial Materials Report,
1, No. 4, 38-41, New York, Van Nostrand ReinholF-Co.l 1981.
Sax, N.I., Ed., Materials Report,
2, N,3. 4, N 1982.
Sax, N.I., Ed., Dangerous Properties of Industrial Materials Report,3, No. 3, 53-59, New York, Van Nostrand Reinhold Co., 1983.
Seba, D.B. , Milam, M. J. and Laseter, J.L. "Uptake, measurement and elimination of synthetic chemicals by man",in Brostoff, J. and Challacombe, s.i.(Eds) Food Allergy and Intolerance, London:
Bailliere Tindall, 1987.
Sherwood, R. J. and Carter, F.W. G. , "The measurement of occupational exposure to benzene vapour," Ann. Occ. Hyg. 13: 12S-146, 1970.
Snyder, C.A. , Erichman, M.N. , Goldstein, B.D. , and Laskin, S. , "An extraction method for determination of benzene in tissue by gas chromatography," Am. Ind. Hyg. Asso. J. 38: 272-276, 1977.
Sperber, I. , "A direct turbidimetric method for determining ethereal sulfates in urine," J. Biol. Chem. 172: 441-444, 1948.
U.S. Dept. of Health and Human Services, Second Annual Report on Carcinogens, Research Triangle Park, N.C. Decemb r, 1981.
U.S. Dept. of Health and Human Services. Third Annual R t on Carcinogens, Research Triangle Park, N.C., December, 1982.
U.S. Environmental Protection Agency, Benzene: Ambient Water Quality Criteria, Washington, D.C., 1980.
U.S. Environmental Protection Agency, Status Assessment of Toxic Chemicals: Benzene, Report EPA-600/2-79-210D, Washington, D.C., Dec. 1979.
U.S. Environmental Protection Agency, Benzene, Health and Environmental Effects Profile No. 15,, Washington, D.C., Office of Solid Waste, April 30, 1980.
United Nations Environment Programme, IRPTC Legal File 1983, Vol. 1, pp VII/69-73, Geneva, Switzerland, International Register of Potentially Toxic Chemicals, 1984.