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CAS No. 100-42-5
Styrene (C₆H₅CH=CH₂) is a colorless liquid that evaporates easily and has a sweet smell. Breathing high levels of styrene may cause changes in color vision, tiredness, feeling drunk, slowed reaction time, concentration problems, or balance problems. Hearing loss has been observed in animals exposed to very high concentrations of styrene.

Workers may be harmed from exposure to styrene. The level of exposure depends upon the dose, duration, and work being done. Styrene is widely used to make plastics and rubber. It’s used in insulation, fiberglass, plastic pipes, automobile parts, shoes, drinking cups and other food containers, and carpet backing.

Some examples of workers at risk of being exposed to styrene include the following:

  • Workers in the reinforced plastics industry
  • Workers involved in styrene polymerization
  • Factory workers in rubber manufacturing
  • Workers in industries that use styrene polyester resin
  • Employees of photocopy centers

NIOSH recommends that employers use Hierarchy of Controls to prevent injuries.  If you work in an industry that uses styrene, please read chemical labels and the accompanying Safety Data Sheets for hazard information. Visit NIOSH’s page on Managing Chemical Safety in the Workplace to learn more about controlling chemical workplace exposures.

The following resources provide information about occupational exposure to styrene. Useful search terms for styrene include “ethenyl benzene,” “phenylethylene,” “styrene monomer,” “styrol,” and “vinyl benzene.”

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