Ozone Safety & Health Effects

Ozone Safety:

Ozone is a strong oxidizer that is generally not harmful to mammals at low concentrations, but lethal to microorganisms such as bacteria, viruses, and mold. However, ozone, like any other strong oxidizing agent, can be harmful if not handled properly. The federal government has set guidelines for safe ozone limits in occupied spaces as well as for use in food and water sanitation. But more importantly, Ozone Solutions encourages the use of the proper monitoring and/or destruct equipment to further ensure safety.

The government oversees ozone levels through three primary agencies, depending how ozone is intended to be generated: OSHA/NIOSH, EPA, and USDA/FDA.


OSHA guidelines for ozone in the workplace are based on time-weighted averages. OSHA has set official exposure limits for ozone at no more than 0.1 ppm average over an 8-hour period. OSHA does provide guidelines for exposure limits that may vary from that standard, based on exposure time. For more information, please visit the OSHA website.

Unlike OSHA, NIOSH safety and health standards are not enforceable under US law. However, NIOSH does "develop recommendations for health and safety standards" that may influence law and OSHA regulations. The NIOSH recommended exposure limit for ozone is 0.1 ppm (0.2 mg/m3). According to NIOSH, Ozone levels of 5 ppm or higher are considered immediately dangerous to life or health. For more information: NIOSH Pocket Guide to Chemical Hazards: Ozone.

Safety Data Sheet:

By coming into contact with higher levels of ozone, there are potential health effects as listed on the Ozone Material Safety Data Sheet (MSDS), including:

By Inhalation: Ozone can cause dryness of the mouth, coughing, and irritation of the nose, throat, and chest. It may cause labored breathing, headaches, and fatigue. However, the characteristic sharp, pungent odor is readily detectable at low concentrations. Corrective measure: Move to fresh air and loosen tight clothing around torso. Seek medical attention if breathing continues to be difficult.

Through Skin: Absorption through intact skin is not expected. Corrective Measure: Wash skin thoroughly with soap and water.

Via Eye Contact: Ozone can be an irritant to the eyes, causing minor inflammation. Corrective measure: Flush eyes with large amounts of water for at least 15 minutes while holding eyelids apart to ensure flushing of entire eye surface.

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

USDS & FDA Regulations:
The USDA and FDA are responsible for regulating safety in food production. Ozone has been given GRAS (Generally Recognized as Safe) approval by the USDA and the FDA for direct contact with food products, including all meat and poultry products. Additionally, ozone has been certified by the USDA National Organic Program as an acceptable additive in the growing or production of organic foods. While good manufacturing procedures must be in place, no regulations exist on levels of ozone in food processing applications. 

USDA final rule on ozone dated 12/17/2002, FSIS Directive 7120.1 Safe and suitable ingredients used in the production of meat and poultry.

FSIS Directive 7120.1 States: Ozone for use on all meat and poultry products. Ozone can be used in accordance with current industry standards of good manufacturing practice.

For more detailed information on these regulations, visit Ozone Solutions Blog-USDA & FDA Ozone Regulations

The FDA, as an agency of the Department of Health and Human Services, is also responsible for the regulation of medical devices. As part of that oversight, the FDA has set a limit on ozone production by indoor medical devices at no more than 0.05 PPM at any given time.

Environment Protection Agency (EPA):

As it pertains to ozone, that would include pollutant emissions in the air, and ensuring clean, safe water (and limiting water contamination). Gaseous ozone levels created by ozone generators in a work environment should be monitored for safe levels and is overseen by OSHA. This type of ozone generation is different than the ozone produced via smog, which is the primary concern for the EPA.

The EPA also regulates ozone in water. Specifically, in bottled water applications, the residual dissolved ozone levels are limited to 0.4 ppm. Even at this level, the EPA has confirmed that Ozone Kills E. coli O157:H7 in Drinking Water. Additionally, ozone does not introduce chemicals into the environment via groundwater like chlorination or acids may do. Research has also shown that ozone can also be effective at removing dangerous pharmaceutical residue from existing groundwater. 

Safety Equipment:
For safety protection, personal awareness of an odor of ozone should not be relied upon. In any setting where ozone is being generated, ALWAYS have an ozone monitor present. Effective monitoring equipment should be able to measure ambient ozone levels and perform the following safety functions:
Initiate an alarm signal at an ambient ozone level of 0.1 ppm. Equipment can stay operational if desired.
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 odor detection threshold is 0.005-0.02 ppm.
When dealing with high concentrations of ozone (shock treatment) an essential safety measure is the use of an ozone destruct unit. An ozone destruct unit will safely destroy any excess ozone that is present in the ambient air or ozone that is off gassed from a contact tank, allowing a space to be safely occupied.