Ozone Safety

Ozone is a strong oxidizer that is generally not harmful to mammals at low concentrations, but lethal to microorganisms such as bacteria. However, ozone, like any other strong oxidizing agent, can be harmful if not handled properly.


Ozone Affecting Health - Observed Effects

Concentration (ppm)

Threshold of odour, normal person


Maximum 8 hr. average exposure limit


Minor eye, nose, and throat irritation, headache, shortness of breath


Breathing disorders, reduced oxygen consumption, lung irritation, severe fatigue, chest pain, dry cough


Headache, respiratory irritation, and possible coma. Possibility of sever pneumonia at higher levels of exposure


Immediately dangerous to life and health


Lethal to small animals within two hours



Inhalation: Ozone causes dryness of the mouth, coughing, and irritation of the nose, throat, and chest. It may cause 
laboured breathing, headaches, and fatigue. However, the characteristic sharp, pungent odour is readily detectable at low concentrations (0.005 to 0.02 PPM). 

Corrective Measure: Move to fresh air, loosen tight clothing around the torso. 
Call medical attention if necessary. 
If breathing is difficult, a trained person/EMT should administer oxygen at 15 LPM via non-re-breather.

Skin: Absorption through intact skin is not expected. 

Corrective Measure: Wash skin thoroughly with soap and water.

Eye Contact: Ozone can be an irritant to the eyes causing minor 

Corrective Measure: Flush eyes with large amounts of water for at least 15 
minutes while forcibly holding eyelids apart to ensure flushing of the entire 
eye surface. If irritation, pain, or other symptoms persist seek professional 
medical attention.

Ingestion: It is not a route of exposure.

Aggravation of Pre-existing Conditions: Ozone may 
increase sensitivity to bronchia constrictors including allergens, especially individuals with asthma.

Chronic Condition: Long term health effects are not expected 
from exposures to ozone. A partial tolerance appears to develop with repeated exposures. 

For safety protection, personal awareness of an odour of ozone should not be relied upon. Instrumentation and equipment should be provided to measure ambient ozone levels and perform the following safety functions:

  1. Initiate an alarm signal at an ambient ozone level of 0.1 PPM. Equipment can stay operational, if desired.
  2. Initiate a second alarm signal at ambient ozone levels of 0.3 PPM. This signal would also immediately shut down the ozone generation equipment. The majority of humans can smell ozone long before it is dangerous. The odour detection threshold is 0.005-0.02 PPM

how ozone works steri-bed


steri-bed in action