By Mike Franco, Founder, Forever Ozone
Are Ozone Air Purifiers Safe?
No. Low-output ozone devices marketed as continuous air purifiers are not safe for occupied spaces, which is why the California Air Resources Board (CARB) banned their sale in the state. Breathing ozone at elevated levels can irritate and damage the lungs. Ozone generators that look like ordinary air purifiers (Feature filters, etc) have caused hospital visits when people turned them on overnight in bedrooms or Airbnb units, confusing them for air purifiers.
My Experience Testing Indoor Air
Before founding Forever Ozone, I sold air purifiers and worked testing indoor air for an environmental testing company. I measured particle counts and learned that portable air purifiers mostly clean a small bubble of air right next to the unit. Five feet away, readings often stayed high.
The biggest surprise was the #1 indoor air allergen: dust mite feces. According to the NIH StatPearls chapter on dust mite allergy, the house dust mite is a predominant source of indoor aeroallergens. Ninety-seven percent of people with dust mite allergy are sensitized to Der p 1, a cysteine protease excreted in the mites’ fecal pellets. These pellets are typically 10–40 microns. Filters can trap many of the pellets, but the protein itself remains biologically active. That finding is what led me into ozone. Filters alone were not solving the problem for my allergy customers.
Ozone Air Purifiers vs. Ozone Shock Treatments
There is a clear difference:
- Ozone air purifiers produce low, continuous ozone intended for occupied rooms. Even modest output can accumulate to harmful levels, especially in cooler conditions. These are the devices California restricted.
- Commercial ozone generators for shock treatment produce high concentrations for short periods in unoccupied spaces only (no people, pets, or plants present). After treatment the space is thoroughly ventilated before re-entry. This is the industrial/remediation use that remains legal when properly labeled and used.
Our machines are built and marketed solely for the second category. They look like open science-lab equipment, not consumer air cleaners, and they carry the required industrial-use advisory.
Practical Steps That Actually Improve Indoor Air
- Run your HVAC fan continuously with a MERV 11 or 12 filter and change it every three weeks. A carton of 12 filters is inexpensive and moves far more air than any portable purifier.
- Control humidity and source odors instead of masking them.
- For mold, mites, smoke damage, or heavy biological load, perform a properly sized ozone shock treatment in an unoccupied space, post a warning sign, and air the space out thoroughly afterward. First-time users get an included 30-minute shock treatment consultation, so the ozone shock treatment protocol matches the space and the goals.
- Avoid air fresheners. They mask odors and add chemicals. EWG reported that a University of Washington study found half of the air fresheners tested released acetaldehyde (classified by the EPA as a likely human carcinogen). EWG’s own testing of one popular product detected 89 airborne contaminants, including acetaldehyde. Phthalates and other undisclosed fragrance chemicals are common.
California Buyers
If you are in California, our terms require you to act as a contractor for industrial-use remediation, post a “Ozone Shock Treatment in Progress” sign, and follow all applicable rules. We do not sell continuous ozone air purifiers. If you are new to the process, call or text 501-654-4330 for the included 30-minute shock treatment consultation.
Ozone is like fire: the same molecule can be useful or harmful depending on concentration, duration, and whether anyone is present. Used only as a short, high-concentration shock treatment in an empty space, followed by thorough ventilation, it is a tool for remediation. Used as a continuous air purifier while people are present, quite frankly, is not safe.
- Sources: NIH/NCBI StatPearls Dust Mite Allergy; EWG “Your best air freshener isn’t an air freshener”; California Code of Regulations Title 17, air cleaner regulation.