Resource: Agency for Toxic Substances and Disease Registry
Click here: for a PDF takeaway of Benzene from the Agency for Toxic Substances and Disease Registry
Benzene is a colorless liquid
- Benzene, also known as benzol, has a sweet odor
- Benzene is highly flammable.
- Benzene is made mostly from petroleum sources. Various industries use benzene to make other chemicals, such as styrene (for Styrofoam® and other plastics), cumene (for various resins), and cyclohexane (for nylon and synthetic fibers).
- Benzene is also used for the manufacturing of some types of rubbers, lubricants, dyes, detergents, drugs, and pesticides.
- Benzene is also a natural component of crude oil, gasoline and cigarette smoke.
Health Effects of Benzene
- The primary target organs for acute exposure are the hematopoietic system, nervous system, and immune system.
- The primary target for adverse systemic effects of benzene following low-level chronic exposure is the hematological system.
- Benzene is a known human carcinogen and is associated with leukemia, especially acute myelogenic leukemia.
- Benzene exposure may also be associated with reproductive and developmental effects based on animal studies.
Toxicokinetics
- Benzene is rapidly absorbed through the lungs; approximately 50% of the benzene in air is absorbed.
- Over 90% of ingested benzene is absorbed through the gastrointestinal tract.
- Absorbed benzene is rapidly distributed throughout the body and tends to accumulate in fatty tissues.
- The liver serves an important function in benzene metabolism, which results in the production of several reactive metabolites.
- At low exposure levels, benzene is rapidly metabolized and excreted predominantly as conjugated urinary metabolites.
- At higher exposure levels, metabolic pathways appear to become saturated and a large portion of an absorbed dose of benzene is excreted as parent compound in exhaled air.
Biomarkers -
Urinary benzene level is the most sensitive biomarker of exposure to low concentrations.
- Urinary levels of several benzene metabolites including muconic acid and S-phenyl mercapturic acid are also sensitive biomarkers of exposure.Minimal Risk Levels (MRLs)
Inhalation
- An MRL of 0.009 ppm has been derived for acute-duration inhalation exposure (?14 days).
- An MRL of 0.006 ppm has been derived for intermediate-duration inhalation exposure (15–364 days).
- An MRL of 0.003 ppm has been derived for chronic-duration inhalation exposure (?1 year).Oral
- No acute- or intermediate-duration oral MRLs were derived for benzene.
- An MRL of 0.0005 mg/kg/day has been derived for chronic-duration oral exposure (?1 year).