What is Benzene?

Benzene is the simplest aromatic hydrocarbon; it has 6 carbon atoms and 6 hydrogen atoms in a hexagonal (ring) structure. Discovered by the English scientist Michael Faraday in 1825, it was named benzene in 1845 by A.W. von Hofmann, the German chemist, who detected it in coal tar.

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’s Toxicity

Benzene is an extremely toxic chemical.  The major effect of chronic or intermittent exposure to benzene is on the blood-forming organs.  Benzene causes harmful effects on the bone marrow and can cause a decrease in blood cells, leading to anemia (low red blood cell counts), cytopenias (low blood counts), or aplastic anemia or pancytopenia (decreases in all blood counts).  Benzene exposure can also cause excessive bleeding and can affect the immune system, increasing the risk of infection.

Benzene is one of a small number of industrial chemicals that is recognized as a known human carcinogen.  Benzene is especially toxic to the blood-forming organs, i.e., the bone marrow and other organs that can produce blood cells.  Benzene causes hematotoxicity (damage to blood cells), immunotoxicity (damage to the immune system), genotoxicity (damage to chromosomes and to genes), reproductive toxicity (damage to sperm, male fertility, ovaries, menstrual cycles, female fertility, the developing fetus and offspring), blood diseases (aplastic anemia, pancytopenia, myelodysplastic syndrome) and cancers, primarily of the blood forming organs (leukemias, lymphomas, and multiple myeloma).

Benzene’s Uses

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.  Benzene is a natural constituent of crude oil and is therefore present in many refined petroleum products, such as gasoline, jet fuel, glues and adhesives, paints, and solvents.