Gasoline

Full Profile

General Information

Gasoline is a colourless, pale brown, or pink volatile liquid that is produced refining crude petroleum oils.^[3] It is a complex mixture of more than 150 chemicals, including mostly hydrocarbons and paraffins, and small amounts of toluene, xylene, ethylbenzene, and benzene.^[3] Trace amounts of additives can also be found in gasoline, such as antiknock compounds, anti-icing and anti-rust agents, and metal deactivators.^[16] A gasoline’s chemical composition depends on factors such as source of the crude petroleum, manufacturer, and time of year.^[3] Gasoline may also be referred to as “petroleum spirit,” “petrol” or “gas”.^[16] See HSDB for more synonyms and product names.^[4]

Gasoline has been classified by IARC as a group 2B carcinogen, possibly carcinogenic to humans.^[2] Some epidemiological studies found elevated risks of cancer at these sites following occupational exposure: pancreas, kidneys, stomach, bladder, testicles, liver, and in the lymphatic and haematopoietic systems.^[2] However, few studies provided sufficient data to identify a dose-response relationship between gasoline exposure and cancer outcome.^[2]

There is limited evidence for the carcinogenicity of gasoline in experimental animals. One study found an increased incidence of skin tumours in mice exposed to naphtha, a crude petroleum distillate similar to gasoline.^[2] Inhalation studies in mice and rats exposed to gasoline have produced inconsistent results.^[2]

Gasoline exposure can cause other harmful effects to the human body, usually due to individual chemicals in the gasoline mixture, such as benzene and lead.^[3] Health effects include irritation of respiratory tract, stomach, and skin as a result of inhalation, ingestion, and handling, respectively.^[3] Inhalation of gasoline vapours or ingestion in large amounts may result in acute nervous system effects such as cardiac arrhythmias, dizziness, headaches, coma, respiratory arrest, and death.^[3] Chronic exposures may also result in neurologic, developmental and genotoxic effects.^[3]

How did CAREX choose this agent for review?

Regulations and Guidelines

Occupational Exposure Limits (OEL)

Canadian Jurisdictions	OEL (ppm)
Canada Labour Code	300 500 [stel]
BC, AB, SK, MB, ON, QC, NL, NB, NS, PE, NT, NU	300 500 [stel]
YT	500
Other Jurisdictions	OEL (ppm)
ACGIH 2010 TLV	300 500 [stel]

Canadian Agencies/Organizations

Agency	Designation/Position	Year
Health Canada	DSL – high priority substance with intermediate potential for exposure	2006[6]

Main Uses

Gasoline is used primarily as fuel for internal combustion engines.^[3]

Gasoline may also be used as an extractant or dilutant for essential oils, a solvent for rubber adhesives, a detergent for precision instruments, and as a finishing agent for artificial leathers.^[4]

Canadian Production and Trade

Activity	Quantity	Year
Domestic production	43.4 million m3 of 'motor gasoline'	2009[21]
Domestic consumption	42.3 million m3 of 'motor gasoline'	2009[21]

Export
Total	7.9 million m3 of ‘motor gasoline’	2009[20]
To US	3.2 million m3 of ‘finished motor gasoline’	2009[22]
Import
Total	5.3 million m3 of 'motor gasoline'	2009[22]
From US	1.1 million m3 of ‘finished motor gasoline’	2009[22]

Occupational Exposures

Inhalation is the major route of exposure to gasoline, though exposure through ingestion and dermal contact can also occur.^[3]

Occupational exposure to gasoline vapours may occur during the production, transport or distribution of gasoline.^[2]

An increased risk of exposure to gasoline vapors is found in service station attendants, gasoline tank truck drivers, workers at bulk loading terminals and marine loading docks, workers who remove and service underground storage tanks and gasoline pipelines, workers who clean up gasoline spills and leaks, and refinery workers.^[3]

Environmental Exposures

The general population’s main exposure to gasoline occurs via inhalation of gasoline vapours during refuelling of automobiles and refuelling or use of other gasoline-powered equipment, such as lawnmowers.^[3] Exposure may also occur via close proximity to gasoline spills, i.e. off-gassing from soils, or use of contaminated water.^[3]

After a gasoline spill or leak, some of its chemical components evaporate, whereas others may dissolve and contaminate groundwater and soil.^[3]

Leaking gasoline storage tanks contribute to groundwater contamination in Canada.^[17] The corrosion of underground gasoline tanks installed in large numbers in the 1950s and 1960s has resulted in an increasing number of leaks in recent decades.^[17] This is an issue of particular importance in Atlantic Canada, where groundwater is widely used.^[17]

Exposure to gasoline components may occur through the consumption of contaminated water. However, most chemicals found in gasoline are removed by municipal drinking water treatment procedures.^[3]

When used as a fuel, gasoline produces a number of chemicals that are emitted in engine exhaust. Some of the gasoline used by engines may also vaporize into the air without undergoing combustion.^[13]

Since 1990, Canada has prohibited the production, import and sale of leaded gasoline to minimize the risks of lead exposure from gasoline.^[15] Exemptions to this regulation include the use of lead in gasoline for competition vehicles, aviation gasoline, farm equipment, boats and trucks weighing >3856 kg.^[15] Information on lead exposure is available through the Lead Profile published by CAREX.^[19]

Gasoline is not reportable to the NPRI in Canada.^[9]

One household product, a gasoline additive, is listed in the US Household Products Database with gasoline as an ingredient.^[10]

Sources

1. Wikimedia Commons Photo
2. IARC (1989) Monograph Summary, Volume 45
3. ATSDR (1995) Toxicological Profile for Gasoline
4. US National Library of Medicine (2010) Hazardous Substances Data Bank entry for gasoline (Search term: ‘Gasoline’)
5. CCOHS (2011) MSDS database
6. Health Canada (2006) Categorization of the Domestic Substances List under CEPA
7. TradeMap (2011) Canadian international trade (free subscription required)
8. Industry Canada (2011) Canadian Company Capabilities
9. Environment Canada (2009) The National Pollutant Release Inventory
10. US Department of Health and Human Services (2010) Household Products Database
11. Environment Canada (2010) Toxic Substances List – CEPA Schedule 1
12. Health Canada (2010) Guidelines for Canadian Drinking Water
13. Health Canada (2004) It’s Your Health Road Traffic and Pollution
14. Health Canada (1987) Exposure Guidelines for Residential Indoor Air Quality
15. Environment Canada (2007) Environment Canada’s gasoline regulations: a discussion paper on the potential extension of exemption for leaded gasoline used in competition vehicles.
16. CCOHS (1999) Chemical Profile for Gasoline.
17. Environment Canada (2010) Groundwater Contamination
18. ChemSources (2011) Database for international chemical suppliers (free subscription required)
19. CAREX (2010) Carcinogen profile: Lead and its inorganic compounds
20. Statistics Canada (2010) Supply and disposition of petroleum products, Canada — Motor gasoline
21. US Energy Information Administration (2010) US imports from Canada of finished motor gasoline
22. US Energy Information Administration (2010) US exports to Canada of finished motor gasoline
    

Other Resources

1. ATSDR ToxFAQ for Chromium (2008)
2. EPA (1984), Health assessment document for Chromium. Research Triangle Park, NC: Environmental