Benzene, or benzol, is an organic chemical compound and a known carcinogen with the molecular formula C6H6. It is sometimes abbreviated Ph–H. Benzene is a colorless and highly flammable liquid with a sweet smell and a relatively high melting point. Because it is a known carcinogen, its use as an additive in gasoline is now limited, but it is an important industrial solvent and precursor in the production of drugs, plastics, synthetic rubber, and dyes. Benzene is a natural constituent of crude oil, and may be synthesized from other compounds present in petroleum. Benzene is an aromatic hydrocarbon and the second [n]-annulene.
([6]-annulene), a cyclic hydrocarbon with a continuous pi bond.
Today benzene is mainly used as an intermediate to make other chemicals. Its most widely-produced derivatives include styrene, which is used to make polymers and plastics, phenol for resins and adhesives (via cumene), and cyclohexane, which is used in the manufacture of Nylon. Smaller amounts of benzene are used to make some types of rubbers, lubricants, dyes, detergents, drugs, explosives, napalm and pesticides.
In both the US and Europe, 50% of benzene is used in the production of ethylbenzene / styrene, 20% is used in the production of cumene, and about 15% of benzene is used in the production of cyclohexane (eventually to nylon).
Benzene has been used as a basic research tool in a variety of experiments including analysis of a two-dimensional gas.
Benzene exposure has serious health effects. Outdoor air may contain low levels of benzene from tobacco smoke, automobile service stations, the transfer of gasoline, exhaust from motor vehicles, and industrial emissions. Vapors from products that contain benzene, such as glues, paints, furniture wax, and detergents, can also be a source of exposure, although many of these have been modified or reformulated since the late 1970s to eliminate or reduce the benzene content. Air around hazardous waste sites or gas stations may contain higher levels of benzene.
The short term breathing of high levels of benzene can result in death, while low 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, and death.
The US Occupational Safety and Health Administration (OSHA) have set a permissible exposure limit of 0.5 part of benzene per million parts of air (.5 ppm) in the workplace during an 8-hour workday, 40-hour workweek. The short term exposure limit for airborne benzene is 5 ppm for 15 minutes.
The major effects of benzene are chronic (long-term) exposure through the blood. Benzene damages the bone marrow and can cause a decrease in red blood cells, leading to anaemia. It can also cause excessive bleeding and depress the immune system, increasing the chance of infection. Benzene causes leukaemia and is associated with other blood cancers and pre-cancers of the blood.
Human exposure to benzene is a global health problem. Benzene targets liver, kidney, lung, heart and the brain and can cause DNA strand breaks, chromosomal damage etc. Benzene causes cancer in both animals and humans. Benzene was first reported to induce cancer in humans in the 1920s. The chemical industry claims it wasn’t until 1979 that the cancer inducing properties were determined «conclusively» in humans, despite many references to this fact in the medical literature. Industry exploited this «discrepancy» and tried to discredit animal studies which showed benzene caused cancer saying that they weren’t relevant to humans. Benzene has been shown to cause cancer in both sexes of multiple species of laboratory animals exposed via various routes.
Benzene has been connected to a rare form of kidney cancer in two separate studies, one involving tank truck drivers, and the other involving seamen on tanker vessels, both carrying benzene laden chemicals.
The US Department of Health and Human Services (DHHS) classifies benzene as a human carcinogen. Long-term exposure to excessive levels of benzene in the air causes leukaemia, a potentially fatal cancer of the blood-forming organs, in susceptible individuals. In particular, Acute myeloid leukaemia or acute non-lymphocytic leukaemia (AML & ANLL) is not disputed to be caused by benzene.
Several tests can determine exposure to benzene. There is a test for measuring benzene in the breath; this test must be done shortly after exposure. Benzene can also be measured in the blood; however, because benzene disappears rapidly from the blood, measurements are accurate only for extremely recent exposures. Benzene exposure should always be minimized.
In the body, benzene is metabolized. Certain metabolites, such as Trans, Trans-muconic acid can be measured in the urine. However, this test must be done shortly after exposure and is not a definite indicator of benzene exposure, since the same metabolites may be present in urine from other sources.
The United States Environmental Protection Agency has set the maximum permissible level of benzene in drinking water at 0.005 milligrams per liter (0.005 mg/L). The EPA requires that spills or accidental releases into the environment of 10 pounds (4.5 kg) or more of benzene be reported to the EPA.
The US Occupational Safety and Health Administration (OSHA) have set a permissible exposure limit of 0.5 part of benzene per million parts of air (.5 ppm) in the workplace during an 8-hour workday, 40-hour workweek. The short term exposure limit for airborne benzene is 5 ppm for 15 minutes.
Our Lab tests:
Synonym/Component: Benzol; Cyclohexatriene; Phenylmercapturic acid
Class: Occupational/Environmental Toxin
SPECIMEN REQUIREMENT:
Specimen Type: Aliquot of random or spot urine collection
Tube Type: Urine transfer tube without preservative
Specimen Handling: Tubes should be filled to prevent loss of volatile compound into headspace.
Specimen Volume: 10 mL
Collection Time: End of shift
Storage and Transport Temp: Refrigerate; specimen may also be frozen.
ASSAY PARAMETERS:
Validation: In-house validated method
Methodology: High Performance Liquid
