Styrene is an industrial chemical used to manufacture a wide variety of plastic, rubber and other products. Styrene resins are used extensively in the manufacture of polystyrene packaging, thermal insulation, and disposable cups and containers, rubber used in tires and many other products. Because of their ubiquitous use in industry, hundreds of thousands of employees are potentially exposed to styrene. 

Documented health effects of occupational exposure to styrene include respiratory tract and eye irritation and effects to the nervous system. The National Toxicology Program (NTP) has classified styrene as reasonably anticipated to be a human carcinogen and the International Agency for Research on Cancer (IARC) categorized styrene as possibly carcinogenic to humans. 

The current OSHA PEL of 100 ppm is two to five times higher than the limits issued by CAL-OSHA, NIOSH, ACGIH, and the European Union. Styrene received considerable interest from stakeholders in a 2010 web forum on Permissible Exposure Limits (PELs). OSHA is requesting information about occupational exposures to styrene including uses, administrative and engineering controls for managing exposures, health effects, risk assessment, potential substitutes, and more, in order to determine the need for a revised PEL.