Benzene is a colorless, flammable liquid. Benzene is produced during incomplete combustion of carbon-rich substances. Benzene is produced naturally in forest fires and volcanoes. Benzene is a known carcinogen and a major compound in cigarette smoke.
Benzene has been used since the mid 1800's from consumer products such as after shave to today its contined use as an additive in cigarettes. Benzene is mostly commonly used as an additive to other chemicals. It is used to make styrene, which is used to make plastics and polymers, and in the manufacturing process of nylon. Small amounts of benzene are used in the manufacturing processes of drugs, detergents, synthetic rubbers, dyes, pesticides, and explosives. Benzene is less dense than water and will float on the surface of water. Benzene is still widely used in the United States and ranks among the top 20 chemicals produced. Benzene has been found in several hazardous waste sites in the United States which have been identified by the Environmental Protection Agency (EPA).
Research has shown benzene to be cancer-causing or carcinogenic. With exposures from less than five years to more than 30 years, people have developed and died from leukemia. Long-term benzene exposure may affect bone marrow and blood production. 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. 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.
Almost 300,000 people per year are exposed to benzene in the workplace. Workers in industries that make or use benzene may be exposed to high levels of this chemical. These industries include the rubber industry, oil refineries, chemical plants, shoe manufacturers, and gasoline related industries. In 1987, OSHA estimated that about 237,000 workers in the United States were potentially exposed to benzene. It is not known if this number has changed since that time. Workers in industries that make or use benzene may be exposed to high levels of this chemical. These industries include the rubber industry, oil refineries, chemical plants, shoe manufacturers, and gasoline related industries.
Also included are the following broad categories: Detergent producers; Pesticide producers ; Gasoline producers; Solvent producers; Paint and varnish producers; Adhesive producers; Rubber industry processors ; Petroleum industry processors; Chemical workers; Waste management; Laboratory technicians ; Auto mechanics; Painters; Printers and graphic arts industry; Degreasing operations; Extraction and Sampling (industrial labs); Hauling, loading, unloading and tank cleaning operations; Burning of organically originated materials - wood burning, garbage burning, insulation materials, hydraulic fluids (fire-fighters, law enforcement, technicians, laborers); Rubber and rubber coating, adhesives, sealants; Engine emissions.
There is increased incidence of leukemia when people are occupationally exposed to benzene. Long-term exposure to benzene can cause cancer of the blood-forming organs. Leukemia is a cancer of blood-forming cells in the bone marrow. EPA has classified benzene as a known human carcinogen.
The evidence linking benzene and cancer predominantly comes from studies of workers, and relates to leukemia, particularly with two types called acute myeloid leukemia (AML) and to a lesser degree, chronic lymphocytic leukemia (CLL).
Epidemiologic studies of benzene show a fairly consistent excess risk to exposed workers of leukemia and potentially the below described cancer and blood disorders: Aplastic Anemia; Pancytopenia; Acute Myelogenous Leukemia (AML); Erythroleukemia; Myelomonocytic Leukemia; Acute Promyelocytic Leukemia; Chronic; Myelogenous Leukemia; Acute Lymphoblastic Leukemia; Hairy Cell Leukemia; Chronic Lymphocytic Leukemia; Hodgkin's Disease and Non-Hodgkin's Lymphoma; Paroxysmal Nocturnal Hemoglobinuria; Multiple Myeloma; Lymphomas; Thrombocythemia; Thrombocytopenia; Myelofibrosis; Myelodysplastic Syndrome.