Gasoline’s widespread use raises concerns about its potential to cause cancer. Understanding the scientific evidence involves examining its chemical composition, how exposure occurs, and the specific health outcomes linked to its components. This article explores the current scientific understanding of gasoline’s potential to cause cancer, drawing on research and classifications from leading health organizations.
Hazardous Components of Gasoline
Gasoline is a complex mixture of approximately 150 chemicals derived from crude oil. Several compounds within it are recognized for their potential to cause harm, including carcinogenic effects. Benzene, toluene, ethylbenzene, and xylene (BTEX compounds) are key constituents, with benzene being of particular concern due to its established carcinogenicity.
Beyond BTEX, gasoline contains polycyclic aromatic hydrocarbons (PAHs) and 1,3-butadiene, both human carcinogens. Methyl tertiary-butyl ether (MTBE) is an additive classified as “possibly carcinogenic to humans” based on animal studies, though its link to human cancer is less conclusive. Organizations like IARC, EPA, and WHO consistently classify benzene as a known human carcinogen.
Pathways of Exposure
Exposure to gasoline occurs primarily through inhaling vapors, direct skin contact, and accidental ingestion. Inhalation is the most frequent pathway for the general public, often during vehicle refueling. Vapors can also come from contaminated soil or water, or accumulate in enclosed storage spaces.
Occupational exposure involves higher, more prolonged contact. Workers like gas station attendants, mechanics, refinery employees, and tanker drivers face elevated exposure to vapors and liquid gasoline. Dermal absorption occurs through spills or direct handling, with prolonged contact increasing absorption. Ingestion is less common, usually from contaminated water.
Linked Cancer Risks
Scientific bodies have evaluated the carcinogenic potential of gasoline. In March 2025, the International Agency for Research on Cancer (IARC), a division of the World Health Organization, classified automotive gasoline as “carcinogenic to humans” (Group 1), its highest classification. This determination was based on sufficient evidence linking prolonged exposure to urinary bladder cancer and Acute Myeloid Leukemia (AML) in adults.
Benzene, a significant gasoline component, is a well-established human carcinogen linked to leukemia, especially AML. Studies show higher AML rates among workers with high benzene exposure. While evidence is strongest for AML and bladder cancer, IARC noted limited evidence for other cancers, including ALL, CLL, multiple myeloma, non-Hodgkin lymphoma, myelodysplastic syndromes, and stomach and kidney cancers. Animal studies also link gasoline vapor exposure to kidney and liver tumors.
Reducing Your Exposure
Minimizing contact with gasoline and its vapors reduces health risks. Handle gasoline in open, well-ventilated areas to prevent vapor accumulation. Avoid direct skin contact by wearing protective gloves and not using gasoline as a cleaning agent. If gasoline spills on clothing, remove it immediately and wash hands thoroughly.
Proper storage is a key preventive measure. Keep gasoline in approved containers, stored in detached, well-vented areas, not inside homes or vehicle passenger compartments. Gasoline vapors are heavier than air, accumulating in low-lying areas and posing health and fire hazards. Clean up spills promptly and dispose of contaminated materials properly.
Safety Standards and Regulations
Regulatory bodies establish safety standards to protect the public and workers from gasoline exposure. Organizations like the EPA and OSHA set guidelines and limits for gasoline chemicals. For example, the EPA limits benzene in U.S. gasoline to an average of 1.3% by volume, though typical gasoline may contain 0.5% to 2.0% benzene.
Technological measures, such as gas station vapor recovery systems, reduce gasoline vapor release during refueling. Workplace safety guidelines also manage occupational exposures where gasoline is handled regularly. IARC classifications provide a scientific basis influencing national regulations and public health advisories concerning gasoline and its components.