Title: Gasoline
Additional Names: Petrol (British); Benzin (German)
Literature References: A mixture of C4 to C12 hydrocarbons. Natural gasoline, obtained by fractional distillation of petroleum, contains mostly saturated hydrocarbons; commercial grades of motor gasoline contain paraffins, olefins, naphthenes, and aromatics, all in substantial concns. Motor gasolines are made chiefly by cracking processes, in which heavier petr fractions are converted into more volatile fractions by thermal or catalytic decompn; have also been made commercially by catalytic high-pressure hydrogenation of soft coal and by catalytic synthesis of hydrocarbons from carbon monoxide and hydrogen. Some gasolines sold in the U.S. contain a minor proportion of tetraethyllead added to motor gasoline to increase the octane numbers and thereby prevent "knock" in engines in which the gasoline is used as fuel. Knock is the audible manifestation of an excessive rate of pressure rise when the gasoline vapor is ignited under compression in an engine. The relative knocking tendencies of gasolines are measured in terms of "Octane Number," which is defined as the percentage of iso-octane, having "100 Octane No.," to be blended with n-heptane, having "0 Octane No." by definition, in order to obtain the same degree of knock as is obtained with the gasoline being rated, under standard conditions in a standardized test engine. Additives such as ethanol, methanol, benzene, toluene, MTBE and MMT, q.q.v., are replacing tetraethyllead, and only a small percentage of leaded gasoline is sold in the U.S. Review: J. C. Lane in Kirk-Othmer Encyclopedia of Chemical Technology vol. 11 (Wiley-Interscience, New York, 3rd ed., 1984) pp 652-695. Review of toxicity: N. K. Weaver, Ann. N.Y. Acad. Sci. 534, 441-451 (1988); of carcinogenicity: M. A. Mehlman, Toxicol. Ind. Health 7, 143-152 (1990); of toxicology and human exposure: Toxicological Profile for Gasoline (PB95-264206, 1995) 224 pp. Symposium on toxicology, exposure and health effects: Environ. Health Perspect. 101, Suppl. 6, 1-212 (1993).
Properties: Gasoline is a highly flammable, mobile liq with characteristic odor; evaporates quickly. Flash pt 40-70°C. bp 32-210°C. Explosive limits, vol % in air: lower 1.3, upper 6.0. Insol in water. Freely sol in abs alcohol, ether, chloroform, benzene. Dissolves fats, oils, natural resins. LD50 orally in rats: 18.85 ml/kg (Weaver).
Boiling point: bp 32-210°C
Flash point: Flash pt 40-70°C
Toxicity data: LD50 orally in rats: 18.85 ml/kg (Weaver)
CAUTION: Potential symptoms due to mild overexposure by ingestion may include inebriation, vomiting, vertigo, drowsiness, confusion and fever; severe overexposure by ingestion may result in mild excitation, loss of consciousness, convulsions, cyanosis, congestion, capillary hemorrhaging of the lungs and internal organs, and death due to circulatory failure. Aspiration may cause severe inflammatory reaction and chemical pneumonitis. Direct contact may cause irritation of skin, eye, mucous membranes. Prolonged skin exposure may result in a chemical burn; repeated exposure may cause defatting of the skin. Potential symptoms due to acute overexposure by inhalation of vapor may include irritation and burning in the respiratory system, dizziness, anesthesia, bronchopneumonia, asphyxiation; inhalation of vapor at high levels may induce CNS depression, coma, convulsions, myocardial irritability. Potential symptoms due to chronic overexposure by inhalation may include vomiting, diarrhea, insomnia, headache, dizziness, anemia, impairment of renal function, muscle and neurological symptoms. See Patty's Industrial Hygiene and Toxicology vol. 2B, G. D. Clayton, F. E. Clayton, Eds. (Wiley-Interscience, New York, 4th ed., 1994) p 1395-1406; Weaver loc. cit. Potential occupational carcinogen. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 150.
Use: As fuel in internal combusion engines of the spark-ignited, reciprocating type; diluent; finishing agent; industrial solvent. |