Ozone Approvals Summary


Approvals, Recommendations and Guidelines:



  • More than 100 years of ozone use worldwide
  • United States Food and Drug Administration approved for bottled water in 1982
  • EPA allows use of ozone with no reporting or record-keeping
  • FDA Expert Panel approved as GRAS (generally recognized as safe) in 1997
  • FDA granted petition for use with fruits, vegetables, meat, poultry, in June 2001
  • Approved under USDA Organic Rule in 2000 Regulatory Details:

EPA Requirements for Ozone Under the FIFRA


When the FIFRA was enacted years ago, EPA was required to regulate any chemical for which a pesticidal claim is made. An example of a claim made by purveyors of ozone equipment that can be considered to be a pesticidal claim is “ozone kills/inactivates microorganisms (SARS-CoV-2/Covid-19), fungi, molds, algae, etc.). Pesticides historically are chemicals of commerce that are supplied in bulk in cylinders or containers that are shipped throughout a geographic region. Ozone does not fall into that category of “chemicals”, in that it is generated and used on-site, is not transported or stored, and quickly dissipates or is self-destroyed during use.

Consequently, in interpreting the requirement of the FIFRA, EPA concluded that ozone is not a “pesticide chemical”, and therefore the gas itself is not to be regulated under the FIFRA. However, ozone generators, while not chemicals, are regulated under the FIFRA as “pesticide devices”, as is equipment that produces ultraviolet radiation.

Under the FIFRA, EPA requires that all pesticide devices (which includes ozone generators) that are made or distributed in the USA, for which a pesticidal claim is made must carry an Establishment Number. This is a number granted by the EPA upon receipt of a properly completed EPA Form 3540-8 (rev. 5/99), “APPLICATION: ESTABLISHMENT REGISTRATION FOR PESTICIDE

AND DEVICE PRODUCERS”. Once an Establishment Number has been assigned to a manufacturing facility,

that number is required to be placed on devices (ozone generators) produced at that facility.

The establishment number confirms that the facility that manufactures ozone generating devices has complied with the registration requirements of the FIFRA.

Purfresh EPA Pesticide Device Establishment Number: 66769-CA-2

CDC Infection Control Sterilization Methods


Ozone has been used for years as a drinking water disinfectant. Ozone is produced when O2 is energized and split into two monatomic (O1) molecules. The monatomic oxygen molecules then collide with O2 molecules to form ozone, which is O3. Thus, ozone consists of O2 with a loosely bonded third oxygen atom that is readily available to attach to, and oxidize, other molecules. This additional oxygen atom makes ozone a powerful oxidant that destroys microorganisms but is highly unstable (i.e., half-life of 22 minutes at room temperature).

A new sterilization process, which uses ozone as the sterilant, was cleared by FDA in August 2003 for processing reusable medical devices. The sterilizer creates its own sterilant internally from USP grade oxygen, steam-quality water and electricity; the sterilant is converted back to oxygen and water vapor at the end of the cycle by a passing through a catalyst before being exhausted into the room. The duration of the sterilization cycle is about 4 h and 15 m, and it occurs at 30-35°C. Microbial efficacy has been demonstrated by achieving a SAL of 10-6 with a variety of microorganisms to include the most resistant microorganism, Geobacillus stearothermophilus.

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. No other guidelines are given on levels or dosages of ozone. Reference 21 CFR 173.368

USDA CFR 173.368

Ozone (CAS Reg. No. 10028-15-6) may be safely used in the treatment, storage, and processing of foods, including meat and poultry (unless such use is precluded by standards of identity in 9 CFR part 319), in accordance with the following prescribed conditions: (a) The additive is an unstable, colorless gas with a pungent, characteristic odor, which occurs freely in nature. It is produced commercially by passing electrical discharges or ionizing radiation through air or oxygen. (b) The additive is used as an antimicrobial agent as defined in CFR 170.3(o)(2) of this chapter. (c) The additive meets the specifications for ozone in the Food Chemicals Codex, 4th ed. (1996), p. 277, which is incorporated by reference. The Director of the Office of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies are available from the National Academy Press, 2101 Constitution Ave. NW., Washington, DC 20055, or may be examined at the Office of Premarket Approval (HFS-200), Center for Food Safety and Applied Nutrition, Food and Drug Administration, 200 C St. SW., Washington, DC, and the Office of the Federal Register, 800 North Capitol St. NW., suite 700, Washington, DC. (d) The additive is used in contact with food, including meat and poultry (unless such use is precluded by standards of identity in 9 CFR part 319 or 9 CFR part 381, subpart P), in the gaseous or aqueous phase in accordance with current industry standards of good manufacturing practice. (e) When used on raw agricultural commodities, the use is consistent with section 201(q)(1)(B)(i) of the Federal Food, Drug, and Cosmetic Act (the act) and not applied for use under section 201(q)(1)(B)(i)(I), (q)(1)(B)(i)(II), or (q)(1)(B)(i)(III) of the act.

USDA Guidance on Ingredients and sources of radiation used to reduce microorganisms on carcasses, ground beef, and beef trimmings:

Ozone is classified a Secondary direct food additive/processing aid allowable for all meat and poultry products.

FDA Federal Register Vol. 66 No.123 June 26, 2001

The Food and Drug Administration (FDA) is amending the food additive regulations to provide for the safe use of ozone in gaseous and aqueous phases as an antimicrobial agent on food, including meat and poultry. This action is in response to a petition filed by the Electric Power Research Institute, Agriculture and Food Technology Alliance.

OSHA Ozone Regulations

OSHA guidelines for O3 in the workplace are based on time-weighted averages. Ozone levels should never exceed the following average: 0.10 ppm (parts per million) for 8 hours per day exposure. For more detailed information on safe ozone levels, see the bullet points below.

The OSHA website cites several ACGIH (American Conference of Governmental Industrial Hygienists) guidelines for ozone in the workplace:

0.2 ppm for no more than 2 hours exposure

0.1 ppm for 8 hours per day exposure doing light work

0.08 ppm for 8 hours per day exposure doing moderate work

0.05 ppm for 8 hours per day exposure doing heavy work

More information: http://www.osha.gov/dts/chemicalsampling/data/CH_259300.html

OZONE Effective & Safe When Rules Followed


Ozone is an extremely effective oxidative disinfectant and has been used in the medical, pharmaceutical, food processing, and water treatment industries for decades.

The reason ozone is used is simple. It can be cheaply and efficiently created on-site, and the disarming effect of ozone on microorganisms is well understood and has been proven as an effective tool for mitigating many different unwanted compounds and microorganisms.

Why does the EPA warn against ozone generators on the market?

Although ozone is an effective tool, it is only effective when used SAFELY.
As an example, bleach is a very effective tool when used for its intended purpose. Bleach is ineffective as a hand soap because it is not designed for human consumption or skin contact.

Companies that produce general-purpose bleach have very clear instructions and recommended safety equipment that should be used when using bleach for the safety of the user.

When using ozone, the same precautions need to be taken, but they are often not clearly stated by the manufacturer of the ozone generator and there are no controls in place on cheaper machines that ensure users are operating the generator effectively or even safely. Therefore, the EPA warns against using these commonly available cheap ozone generators in residential areas.

The Purfresh Difference – Safety First

Ozone is a great tool that can be used to protect people from unwanted and potentially dangerous substances that can be found in residential and commercial spaces. To keep people healthy and safe from these particles and microorganisms, ozone must be used when the space is completely unoccupied, and the ozone must be sensor-level controlled (most cheap ozone generators do not offer sensor-level control). These are the most important safety measures that must be taken in order to use ozone appropriately and effectively.

Purfresh Clean Systems utilize fully automated, remotely controlled devices that have built-in safety features that ensure the space is unoccupied and safe to reenter when the space has been cleaned. These include:

  • Safety placards posted on all entrances and exits to the space being treated.
  • Ozone sensors – Both for controlling the ozone level and for making sure the space is clear of any ozone when the space needs to be accessed again.
  • Warning and control lights
  • Remote control capabilities – This important feature allows operators to turn on and off the equipment from outside the space that is to be cleaned. This isn’t offered by cheap ozone equipment suppliers.
  • Activated Carbon and HEPA filters – These turn on after the ozone treatment to reduce possible excess VOCs, formaldehyde, and small particles and reduce the ozone degradation time.

Ozone and Smog – Incorrect Interpretations

Ozone and smog pollution are often considered together when the topic of ozone use is discussed. These are separate issues, and the industrial production of ozone is NOT a component of smog. Dangerous levels of particulate material, CO2, and other smog-pollution components cause harm to humans. Extremely low levels of atmospheric ozone measured when smog is present are not dangerous to humans.

When ozone is produced naturally without the presence of other harmful contaminants like VOCs and NO2, the ozone breaks back down naturally into oxygen. This is a normal result of the instability of ozone and the short half-life inherent in the ozone molecule.

The important consideration is that ozone is not the cause of the low air quality, but the result. Excess NO2 and VOCs in the air from pollution cause this unhealthy ozone cycle to begin. Therefore, the EPA has instituted ground-level ozone standards. These standards are important, as lowering pollution in our air will improve the unhealthy ozone cycle and improve overall air quality for all people.

Purfresh SPACE equipment is proven to follow and adhere to all ozone application use rules and guidelines issued by the FDA, USDA, EPA, OSHA, and CARB.