What is benzene?

Benzene is a colorless liquid with a sweet odor. It evaporates into the air very quickly and dissolves slightly in water. It is highly flammable and is formed from both natural processes and human activities.

Benzene is widely used in the United States; it ranks in the top 20 chemicals for production volume. Some industries use benzene to make other chemicals which are used to make plastics, resins, and nylon and synthetic fibers. Benzene is also used to make some types of rubbers, lubricants, dyes, detergents, drugs, and pesticides. Natural sources of benzene include volcanoes and forest fires. Benzene is also a natural part of crude oil, gasoline, and cigarette smoke.

Approximately 240,000 people in the United States are exposed to benzene in the workplace. A 2006 study suggests that benzene may be present in many commonly used petrochemical products, even though this very toxic chemical may not be listed on a product’s Material Safety Data Sheet (MSDS). Examples of such products that may contain benzene include:

Commercial hexanes Rubber solvent Petroleum benzine Stoddard solvent Spot remover Naphtha solvents Varsol products

140 Flash aliphatic solvent Alkyd paint Toluene Xylene Ethyl benzene Mineral spirits

What are the health effects of benzene?

Breathing very high levels of benzene can result in death, while high levels can cause drowsiness, dizziness, rapid heart rate, headaches, tremors, confusion, and unconsciousness. Eating or drinking foods containing high levels of benzene can cause vomiting, irritation of the stomach, dizziness, sleepiness, convulsions, rapid heart rate, and death.

The major effect of benzene from long-term exposure is on the blood. Benzene causes harmful effects on the bone marrow and can cause a decrease in red blood cells leading to anemia. It can also cause excessive bleeding and can affect the immune system, increasing the chance for infection.

Some women who breathed high levels of benzene for many months had irregular menstrual periods and a decrease in the size of their ovaries. It is not known whether benzene will affect fertility in men.

Long-term exposure to high levels of benzene in the air can cause leukemia, particularly acute myelogenous leukemia, often referred to as AML. This is a cancer of the blood-forming organs. Benzene is a carcinogen in humans.

Regulation & Policy

Washington State’s WISHA program has rules for controlling exposures to benzene in the workplace.

• Benzene Rule - Chapter 296-849 WAC

Resources

• Benzene Training Kit available from WISHA.
• Much of the information provided in this document is based on the Agency for Toxic Substances and Disease Registry’s ToxFAQ for Benzene.
• Agency for Toxic Substances and Disease Registry (ATSDR) Toxicological profile for Benzene.
• More information about the presence of benzene in petrochemical products is available from the following journal article: Kopstein, M (2006). Potential Uses of Petrochemical Products Can Result in Significant Benzene Exposures: MSDSs Must List Benzene as an Ingredient. Journal of Occupational and Environmental Hygiene. Volume 3, Number 1, pp. 1–8. January 2006.
• Canadian Center for Occupational Health & Safety (CCOHS), Chemical Profile for Benzene.
• National Institute for Occupational Safety & Health (NIOSH) Topic: Benzene.
• Occupational Safety & Health Administration (OSHA), Safety and Health Topic: Benzene.
• The New Jersey Department of Health and Senior Services Right to Know Hazardous Substance Fact Sheet: Benzene.

Ask an Expert

• If you have any questions about benzene exposures, safety & health regulations, or products that might contain benzene, contact WISHA Consultation to request a confidential, no-charge safety & health consultation.