Source: Jenson, fotolia

Ozone is produced in the outdoor air by means of solar irradiation and photochemical smog reactions.

The main source of indoor ozone pollution is contamination through outdoor air as a result of ventilation (e.g. open windows). Ozone formation caused by operating laser printers and copiers is no longer a problem today.

Ventilation systems break down part of the ozone as it travels through the filter and the pipes towards the work area. Indoors, ozone decomposes with a half-life of approximately 30 minutes, partly by reacting with other volatile substances.

High concentrations, resulting in the assessment values being exceeded, are particularly likely during sunny weather at the height of summer. On such days, it is advisable to keep windows and doors closed as far as possible to prevent too much ozone entering indoor rooms. The preferred option should always be to air rooms briefly and thoroughly and then close the doors and windows again.

Further information

  • Ozone - GESTIS Substance Database
  • Ozone - Information desk of the German Umweltbundesamt


Dr Simone Peters

Hazardous substances: handling, protective measures

Tel: +49 30 13001-3320
Fax: +49 30 13001-38001