.

Toxicokinetics and Biomarkers/Environmental Sources of Exposure Normal Human Levels Levels TM ToxGuide General Populations Toxicokinetics Biomarkers . Exposure may occur by inhalation, . is well absorbed by the . Urinary levels of and/or ingestion, or dermal absorption. The inhalation and oral routes and poorly phenylglyoxylic acid can be used to for

most likely mode of exposure is by absorbed through the skin. quantify exposure. However, these inhalation of indoor air. . Once absorbed, styrene is widely metabolites are not specific to styrene. . Styrene is also present in combustion distributed throughout the body, with . Qualitative biomarkers included

products such as cigarette smoke and the highest levels detected in fat. styrene levels in exhaled air and blood Styrene automobile exhaust. . There are several metabolic pathways styrene levels. . Styrene copolymers are also frequently for styrene; the primary pathway is C8H8 used in liquid toner for photocopiers oxidation of the side chain by Environmental Levels and printers. cytochrome P450 to form styrene 7,8- Air . Small amounts of styrene are naturally oxide. The styrene oxide is further CAS# 100-42-5 . Median concentrations in urban and present in foods such as legumes, beef, metabolized to ultimately form September 2011 rural/suburban air samples are 0.07– clams, eggs, nectarines, and spices. mandelic acid, phenylglyoxylic acid 4.6 ppb and 0.06–0.08 ppb. Small amounts can also be present in and or can be conjugated packaged foods by migration from with glutathione to form . Median concentration in indoor air U.S. Department of Health and polystyrene food containers and phenylhydroxylethylmercapturic samples are 0.07–11.5 ppb. Human Services packaging materials. acids. Sediment and Soil Public Health Service . Styrene is rapidly eliminated primarily . Styrene is rarely detected in soil Agency for Toxic Substances in the urine as mandelic acid and samples. Occupational Populations and Disease Registry phenylglyoxylic acid. Water www.atsdr.cdc.gov . The highest potential exposure occurs . Styrene is rarely detected in drinking in the reinforced plastics industry. Reported Human Levels water samples. Contact Information: . Workers involved in styrene Division of Toxicology . Urinary levels of styrene were 0.7-4.1 polymerization, rubber ppb in workers exposed to 3.8-14 ppm and Environmental Medicine manufacturing, and use of styrene- Reference of styrene; average blood styrene levels Applied Toxicology Branch polyester resin may also be exposed. Agency for Toxic Substances and in adults without occupational Disease Registry (ATSDR). 2010. . Workers at photocopy centers or exposure to styrene were 0.22 ppb. 1600 Clifton Road NE, F-62 Toxicological Profile for Styrene. Atlanta, GA 30333 facilities may also be exposed to styrene. Atlanta, GA: U.S. Department of 1-800-CDC-INFO Health and Human Services, Public

Health Services.

Chemical and Physical Information Routes of Exposure Relevance to Public Health (Health Effects)

Styrene is a liquid . Inhalation – Predominant route of Health effects are determined Health Effects exposure for general population is . Styrene is a colorless liquid that by the dose (how much), the . The most sensitive target of toxicity is inhalation of contaminated indoor air. evaporates easily. duration (how long), and the the nervous system. Effects observed Predominant route of exposure for in workers include decreased color . Styrene is a high production chemical workers. route of exposure. primarily used in the production of discrimination, vestibular effects, . Oral – Minor route of exposure via polystyrene plastics and resins, hearing impairment, symptoms of ingestion of food. Minimal Risk Levels (MRLs) copolymers such as styrene- neurotoxicity (particularly “feeling Inhalation acrylonitrile and acrylonitrile- . Dermal – Skin contact may occur drunk” and tiredness), delays in butadiene-styrene, and styrene- during manufacture or use of styrene . An MRL of 5 ppm has been derived reaction time, impaired performance butadiene rubber, or formulated with and styrene products. for acute-duration inhalation exposure on tests measuring attention and unsaturated polyester resins for use as (≤14 days). memory, impaired nerve conduction velocity, and EEG alterations. fiberglass reinforcement materials. Styrene in the Environment . No intermediate-duration inhalation . Consumer products containing styrene MRL was derived for styrene. . Nasal olfactory epithelial damage and . Styrene enters the air, water, and soil include packaging materials, . liver necrosis have been observed in as a result of its manufacture and use. An MRL of 0.2 ppm has been derived insulation, fiberglass, plastic pipes, for chronic-duration inhalation animals. However, humans are likely automobile parts, shoes, drinking cups . Styrene photodegrades in the exposure (≥1 year). to be less sensitive to these effects due atmosphere with a half-life of 7– to species difference in styrene and other food-use items, and carpet 16 hours. metabolism. backing. Oral . A large fraction of the styrene released . DHHS has classified styrene as into water will volatilize into the . An MRL of 0.1 mg/kg/day has been reasonably anticipated to be a human atmosphere. derived for acute-duration oral exposure carcinogen. IARC has assigned (≤14 days). . Styrene is moderately mobile in soil styrene to Group 2B, possibly and is rapidly degraded under aerobic . No intermediate- or chronic-duration carcinogenic to humans. conditions. oral MRLs were derived for styrene.

. Bioconcentration does not appear to Children’s Health be significant for styrene. . Children are expected to be affected by

styrene poisoning in the same manner as adults. . Human studies are not adequate to evaluate the developmental toxicity of styrene. In general, animal studies have not found developmental effects following inhalation or oral exposure.