NIOSH logo and tagline



CAS No. 10028-15-6

Ozone (O₃) is a colorless to blue gas with a pungent odor. Exposure to ozone may cause headaches, coughing, dry throat, shortness of breath, a heavy feeling in chest,  and fluid in the lungs. Higher levels of exposure can lead to more severe symptoms. Chronic exposure may lead to asthma. Workers may be harmed from exposure to ozone. The level of exposure depends upon the dose, duration, and work being done.

Ozone is used in many industries. It is used for purifying air and drinking water, in industrial waste treatment, oils, bleaching and waxes, and to make other chemicals. Some examples of workers at risk of being exposed to ozone include the following:

  • Outdoor workers in areas with high levels of ozone
  • Factory workers in paper and pulp mills
  • Workers in waste water treatment plants
  • Fisheries workers who treat storage water

NIOSH recommends that employers use Hierarchy of Controls to prevent injuries.  If you work in an industry that uses ozone, 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 ozone. Useful search terms for ozone include ” triatomic oxygen.”

NIOSH Chemical Resources