Agent Name


CAS Number




Major Category

Plastics & Rubber


Cinnamene; Ethenylbenzene; Phenylethene; Phenethylene; Phenylethylene; Styrene monomer; Styrol; Styrolene; Vinylbenzene; [CHEMINFO] UN2055




Colorless to yellow, oily liquid with a sweet, floral odor; [NIOSH]


"Styrene is used extensively in the manufacture of plastics, rubber, and resins. About 90,000 workers, including those who make boats, tubs and showers, are potentially exposed to styrene." [] Used to make polystyrene for packaging, insulation for buildings and refrigeration equipment, and disposable cups and containers; Also used in styrene-butadiene rubber, other polymers, and resins to make boats, shower stalls, tires, automotive parts, etc.; [ACGIH]


Liquid causes first degree burns on short exposure; [CHRIS] There is evidence that occupational exposure to styrene in high concentrations over long periods of time can cause chronic encephalopathy similar to "Painters' syndrome" caused by other organic solvents. [Sullivan, p. 1156-7] Occupational asthma confirmed by bronchoprovocation testing in 2 workers in a plastics factory; [Malo] Styrene can induce liver injury in experimental animals. [Zimmerman, p. 367] Styrene can cause defatting of skin and CNS depression. [ICSC] A 1996-99 study of 328 reinforced plastics workers in the US found that air levels have decreased substantially over the last 10-20 years. [Reference #2] "About 95% of the amount absorbed during a 8-hour exposure can be accounted for by urinary excretion of the metabolites mandelic acid (MA) and phenylglyoxylic acid (PGA), which are produced by sequential metabolism." [ACGIH] During the period of 1966 to 1990 the average styrene concentration in the breathing zone of open-mould workers in the European glass fibre-reinforced plastics industry has decreased on average by 5.3% per year and only 0.4% annually in the period after 1990;" [PMID 21926918]

Reference Link

OSHA: Styrene

Exposure Assessment

Mandelic acid plus phenylglyoxylic acid in urine = 400 mg/g creatinine at end of shift; Styrene in urine = 40 ug/L at end of shift; [TLVs and BEIs]

Skin Designation (ACGIH)

Insufficient data


20 ppm


40 ppm


100 ppm, Ceiling(OSHA) = 200 ppm(600 ppm is 5-min. peak in any 3 hrs.)


20 ppm


700 ppm

Excerpts from Documentation for IDLHs

Volunteers exposed to 376 ppm for up to 7 hours experienced unpleasant subjective symptoms and objective signs of neurologic impairment [Stewart et al. 1968]. Drowsiness, nausea, headache, fatigue, and dizziness have been reported in workers exposed to 200 to 700 ppm [AIHA 1959].

Vapor Pressure

6.4 mm Hg

Odor Threshold Low

0.01 ppm

Odor Threshold High

1.9 ppm


980 ppm

Lethal Concentration

LC50 (rat) = 12,000 mg/m3/4H

Explanatory Notes

Detection odor threshold from AIHA (mean = 0.14 ppm); The Guide from the Emergency Response Guidebook is for "Styrene monomer, stabilized." Flash point = 34 deg C;

Half Life

Blood: fast phase = 0.5 hour and a slow phase = 13 hours; for mandelic acid, fast phase = 4 hours and slow = 25 hours; for phenylglyoxylic acid, urinary 1/2 life = 11 hours; [TDR, p. 1088]

Reference Link

Predictors of occupational exposure to styrene and...[Occup Environ Med. 2006] - PubMed Result

Flammability (NFPA)

3: May ignite at ambient temperature

Adverse Effects



CNS Solvent Syndrome


Hepatotoxin, Secondary


Skin Burns

IARC Carcinogen

Possible Carcinogen

NTP Carcinogen

Anticipated Human Carcinogen

ACGIH Carcinogen

Not Classifiable

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information


Chemical Information

Search ChemIDplus

Biomedical References

Search PubMed

Related Information in HazMap

Occupational diseases associated with exposure to this agent:


Industrial Processes with risk of exposure:


Activities with risk of exposure: