California Banned Ozone Generator “Air Purifiers”

By Jeff Scheir

In this op-ed, Jeff Scheir makes his case against using ozone in cultivating cannabis.

California was the first state to step up to defend consumers from false marketing claims that ozone generators are safe, effective air purifiers. In reality, ozone is a lung irritant, especially harmful to allergy and asthma sufferers. In 2009, California became the first state in the nation to ban ozone generators. The Air Resources Board of the California Environmental Protection Agency states:

Not all air-cleaning devices are appropriate for use — some can be harmful to human health. The ARB recommends that ozone generators, air cleaners that intentionally produce ozone, not be used in the home or anywhere else humans are present. Ozone is a gas that can cause health problems, including respiratory tract irritation and breathing difficulty.

The regulation took effect in 2009 along with a ban on the sale of air purifiers that emit more than 0.05 parts per million of ozone. The ARB says that anything beyond this is enough to harm human health; however, some experts say that there is no safe level of ozone.

The National Institute for Occupational Safety and Health recommends an exposure limit to ozone of 0.1 ppm and considers levels of 5 ppm or higher “immediately dangerous to life or health.”

If you’re shopping for an air purifier, it’s best to avoid ozone generators, especially if you have a respiratory condition. Ozone generators, and ionic air cleaners that emit ozone, can cause asthma attacks in humans while doing little to nothing to clean the air.

O3 is a free radical, an oxidizer; when it meets any organic molecule floating around it bonds to it and destroys it. In a grow room, organic molecules include the essential oils in cannabis which produce the fragrance. When using ozone within your grow room, too much will not only all but eliminate the smell of your flowers but with prolonged exposure, it begins to actually degrade the cell walls of trichomes and destroy the structure of the glands.

Despite the claims of some manufacturers, ozone does not have an anti-microbial effect in air unless levels far exceed the maximums of the regulation and is therefore harmful humans.

Keeping the grow room clean of mold and bacteria is important, but ozone is not the technology you want to employ to satisfy this goal. Looking into a combination of UVC and Filtration will better meet the goal while keeping both your plants and staff healthy.


  1. john Oosterveld

    This article mention some half truths and not relevant info for the cannibis industry. Professional ozone suppliers know all about the statements quoted but are taken out of context. As mentioned in the article ozone is a very aggressive sanitizer and needs to be applied appropriately.
    We have ozone installation running in vegetable and flowers greenhouses without any detrimental effects on plants or people. The right levels and timing has to be observed.
    Ozone can be used to very effectively disinfect a grow room when empty because it gets into every nook and cranny, including evaporator coils and in and on top all fixtures.. The article would have benefitted from a balance view instead a lot of fear mongering.

  2. Jonny

    Why isn’t bottle water banned in California? The only reason there is bottled water is the use of Ozone. Also, Los Angeles uses Ozone and is the second-largest water treatment plant in the U.S. to clean and disinfect water.

    1. Greg Frech

      Agree totally. California does not understand the science. Ozone is an oxidizer and is effective at killing bugs at right concentrations and is used by some drinking water purveyors to assist in sanitizing. The standard approach is
      [Effect = concentration x time].
      Anyone who uses chemicals of any kind knows this. California treats citizens like errant stupid children who cannot read or keep themselves safe.

    2. Greg Frech

      And btw, not all bottled water is treated with ozone. Far more likely it is treated with Reverse Osmosis membranes to remove most minerals.

  3. Elizabet Da Furst

    This is simply an outright lie. Ozone machines do not harm your lungs, unless someone shuts you in a small closet and tapes up the gaps, and runs it full blast for days. I have cured my allergies by running several ozone machines in my house several times a day, I ozonate all our water, and clean fruits, vegetables and meat with them. EVERYONE HERE, including our pets, are healthier than ever. No allergies, no COVID, no colds or coughs. The idiots that outlawed these machines in California need to be voted out ASAP. MOST ANNOYING over-reach of government in a long time. COMPLETE GARBAGE THAT THESE ARE UNHEALTHY. Many thousands would have survived COVID by owning one. MAKES YOU THINK, DOESN’T IT? What’s the real goal in banning them?

    1. Dayle Peters

      Thank you for your comment!

      I have searched on how to use ozonated water in daily, practical use. I see spray bottle generators selling for $200 and up. I have seen unit that generate ozone for a cleaner laundry and I have seen stand alone units that create ozone in what ever container that you would like to use.

      I have searched for info on how to use ozonated water, but the articles or videos don’t delve into practical daily use, but mostly I have seen comments that scare me away from trying to use ozone in my home. I don’t think I would want to sanitize the air. Mostly I would use it to clean with.

      Any suggestions? Is there any way you could contact me or I can contact you? I would love to learn more.

      Thank you!

  4. Christian Mackay

    Ozone Generators should be fine for private use if the consumer knows what they are doing. Of course you don’t just sit in front of it and breath it in. The same way you don’t sit in front of a car exhaust, yet those aren’t banned… yet.

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