Don't want to share Covid?

family holidays gathering.jpg

Air Sanitizer




During the COVID-19 pandemic,

it is not possible to be entirely safe from contagion when multiple people gather. However, there are some low-effort ways you can make the environment significantly safer, whether at a family gathering or group event, or in a shared household or workplace.
The US Centers for Disease Control and Prevention states that the main route for the spread of COVID-19 coronavirus is spread is through the air. Sick individuals expel SARS-CoV-2 coronavirus in respiratory droplets and in "aerosols" (fine mists) they breathe out that then reach others. Shared homes, higher numbers of people grouped together, heavier breathing (when exercising, singing, etc.), and unmasked eating and food sharing create especially significant concerns.

The US Centers for Disease Control and Prevention (CDC) confirms that the main routes for transmission of COVID-19 are through the air.

"Exposure occurs in three principal ways:

  1. inhalation of very fine respiratory droplets and aerosol particles,

  2. deposition of respiratory droplets and particles on exposed mucous membranes in the mouth, nose, or eye by direct splashes and sprays, and

  3. touching mucous membranes with hands that have been soiled either directly by virus-containing respiratory fluids or indirectly by touching surfaces with virus on them."

We need to fight SARS-CoV-2 coronavirus

in addition to on people and surfaces.

Airborne Chlorine Dioxide Use2.jpg

Air sanitizer made with mild chlorine dioxide can powerfully combat contagion of airborne diseases.

Chlorine dioxide sanitizer emitted into air can CONTINUOUSLY help reduce coronavirus and other germs in AIR, as well as SURFACES it contacts:
  • people's clothing, skin & hair,
  • desks and chairs, 
  • couches,
  • trash cans,
  • food at restaurants,
  • seats in cars,
  • shared bathrooms,
  • bedding in sickrooms,
  • countertops & stoves,
  • floors,
  • refrigerator doors,
  • & more

Chlorine dioxide is an environmentally friendly chemical compound that can be used among groups of people and in shared spaces to easily help disinfect air and surfaces continuously.

Chlorine dioxide is highly effective at rapidly destroying coronaviruses as well as many other types of germs, even when used at very low concentration levels. At the same time, it is exceptionally safe to use around people, since it reacts strongly with pathogens while only mildly with cells of the human body. Unlike the chlorine formulation in common bleach, it is also very environmentally friendly and is even approved for use in some types of organic-certified food production. It is used very commonly to treat drinking water, fresh produce and meats.

A number of chlorine dioxide-based disinfectants are included on the EPA's List N of disinfectants to use against the COVID-19 coronavirus, and many others not on the list are also very effective against COVID-19. Different amounts of time are listed for "contact time" required for each product to be assuredly destroy coronavirus. However, the listed times are based on test results submitted to the EPA under stringent guidelines. Being an enveloped virus, SARS-CoV-2 is destroyed quite easily and some chlorine dioxide products' formulations are effective more quickly. This is especially true of ones that produce a higher percentage of specifically "free" (pure) chlorine dioxide (versus the percentages labelled as "available chlorine dioxide" or "stabilized chlorine dioxide," or vaguely labelled simply as "chlorine dioxide"). However, some products that contain even amounts of "free" chlorine dioxide that are quite small have been demonstrated to destroy practically all SARS-CoV-2 particles on a surface in about 30 seconds.

Numerous studies have demonstrated that chlorine dioxide used as an air sanitizer has significant effectiveness against a broad range of pathogens in air even when used at extremely low concentrations, such as 0.03 ppm(volume/volume).

Safety standards have been confidently determined by several agencies. The US Occupational Safety and Health Administration (OSHA) affirms that chlorine dioxide in air at an appropriately low level (up to 0.1 ppm(v/v) has no detrimental effects on people even if breathed 8 hours every workday for 45 years!

Airborne Chlorine Dioxide Use2.jpg
Mixing suitable chlorine dioxide disinfectant with
water in an ordinary cool-mist ultrasonic humidifier is
a low-effort way to continuously sanitize shared spaces.

Many common "ultrasonic" humidifiers can be used with chlorine dioxide air sanitizer

Gratefully, many humidifiers suitable for dispensing chlorine dioxide solution into air are readily available in general stores and online.

Requirements for suitable humidifiers:
  1. Humidifiers must be an ultrasonic type. Some humidifiers that are labelled "cool mist" humidifiers are also ultrasonic. Check labels carefully.
  2. The water tank should preferably be opaque. Some types of light degrade chlorine dioxide, so if the humidifier's tank is transparent, you will need to fill it with small amounts of fresh solution more frequently.
    Tip: Spray painting the outside of the tank with dark spray paint might be an option, but paints may have some degree of permeation or other detrimental effect on plastic.
  3. For most ultrasonic humidifiers, you need to use distilled water to avoid causing minerals from water to be misted into air and float as "white dust" (to which some people have sensitivities) and settle on surroundings. Using distilled water also prevents hard water build-up that can eventually ruin components used in ultrasonic humidifiers. Demineralization cartridges can't be used because they may affect chlorine dioxide.
    Note: A few personal-size ultrasonic humidifiers are specifically designed to use tap water.
  4. Look for humidifiers that have durable components. Chlorine dioxide will gradually degrade plastics, rubber and metal components. Life of a humidifier using 100 ppm chlorine dioxide may range from 6 months to 2 years.

Example using a personal Ultrasonic Mini Humidifier

This pictured model of personal-size humidifier has many ideal characteristics.
Office desk w humidifier3.jpg

PROS: Has rechargeable battery so humidifier can be used anywhere, or can run plugged into any USB cord. Requires only tap water (not distilled), and does not spill water when tipped! Lasts several months. Frequent cleaning is not necessary since chlorine dioxide keeps tank disinfected. Each wick can be used 3+ months. Only $25, including 3 spare wicks.

CONS: Red charging light may degrade chlorine dioxide concentration slightly, but its other LED lights can be turned off. If used with very hard water, periodically metal disc on top needs to be gently cleaned using alcohol on cotton swab. USB cord must to be handled gently to prevent loosening.

Product Specs

Humidifier tank size:  320 mL; 

Rechargeable battery life:  5 hours
Time to empty on HIGH flow setting:  6 hours; 

Time to empty on LOW flow setting:  12 hours

Sold on under various brand names
Instructions below ONLY apply for the specific model of ultrasonic humidifier shown on this page.

Use our Chlorine Dioxide Formula Calculators to help calculate chlorine dioxide formula concentrations to use in other humidifiers with different tank sizes and flow rates. 
Within the conditions noted, information here is aimed to help create average air concentrations between 0.03 and 0.1 ppm(v/v) chlorine dioxide in air in the area within a few feet of the humidifier. If you would like to achieve different concentrations in air, you can use our Chlorine Dioxide Formula Calculators to help in estimating appropriate solutions to use.

How to make liquid solution for this humidifier:

Purchase a chlorine dioxide and/or sodium chlorite disinfectant, or ingredients for making chlorine dioxide. Check the label and decide for yourself if you should use that product for the purposes described here.

Read the label to find out at what concentration it should be used

as a "hospital-type" disinfectant.

If product says it is "ready-to-use" for hospital-type uses,

Use it full-strength.

If label says product should be mixed at 100 ppm or 200 ppm for hospital-type uses,

First mix it to that specified concentration. Then make a liquid solution to use in this humidifier by mixing a 50% : 50% solution (1 part water and 1 part hospital-type-strength disinfectant).

If product does not have a label describing hospital-type use but you know the concentration and how to dilute correctly,

Mix it to approximately 150 ppm(w/w)

"free" chlorine dioxide.

  • Note: "CDS" is usually 3,000 ppm(w/w) "free" chlorine dioxide, though may vary. (The concentration of "MMS" is different, and varies widely based on "activation" method and time, and dilution. MMS and technical-grade sodium chlorite also contain impurities that may--or may not--damage the humidifier over time.)

TIP: Chlorine dioxide test strips can be purchased to check "free" chlorine dioxide concentrations. Be sure they are for chlorine dioxide (not chlorine) and cover at least 100 ppm through 300 ppm. (Example 1, Example 2, Example 3).
It is essential to adjust the humidifier's use appropriately to match conditions, as described below. ​
Situations in which this solution may be used in this humidifier on HIGH setting:
  • In indoor areas with at least 16 feet x 16 feet of open space, where air flow is sufficient to gently circulate mist, and lighting is moderate. Humidifier should be turned off for at least 15 minutes every 3 hours.

  • Where people are crowded together, 

  • In indoor or outdoor areas protected from sunlight where a minimum of 8 feet by 8 feet where people are crowded together. (Sanitizing mist will help neutralize germs in the concentrated aerosols.)

  • To help keep chlorine dioxide mist from being degraded by UV light, the humidifier should be placed away from windows and fluorescent light bulbs.

Situations in which this solution may be used in this humidifier on LOW/INTERMITTENT setting.
  • When using in a room smaller than 16 feet x 16 feet for more than 60 mins.

  • In an area with lower air circulation.

  • When an area is darkened.

  • ​In vehicles. *Important:  The fan/blower for the heating/AC/vent system MUST be set for air to flow THROUGH the vehicle (not recirculate), and one window MUST also be opened slightly.

Situations in which this humidifier should be turned OFF.

  • Do not use this humidifier if you do not understand instructions on this page.

  • If you feel shortness of breath, headache, cough, or slight choking sensation.

    • Note: Always keep humidifier at least 18 inches from your mouth and nose.

  • This humidifier emits a hazy mist that fades quickly into surrounding air. If haze builds up to be visible in nearby area, turn off humidifier until haze clears.

  • If the humidifier is going to be unattended (such as during sleeping hours) and conditions listed above may be exceeded.

  • Note: This humidifier automatically turns itself off when tank runs dry (6 hours on High, 12 hours on LOW), or battery needs recharging (4-5 hours when unplugged).


Chlorine dioxide breaks down more quickly when exposed to UV light, including nearby fluorescent light bulbs without plastic covers, LED lights, and sunlight (even when filtered through windows). When little or no UV light is present in a room (such as during sleeping hours), the humidifier use needs to be adjusted to release chlorine dioxide at a slower rate. ​

  • In otherwise appropriate conditions, humidifier may still be used at usual setting if solution is first diluted to 125 ppm(w/w) by mixing 50% water with 50% of 250 ppm(w/w) solution; or

  • In conditions otherwise appropriate for HIGH setting, the humidifier may be used if it is turned down to the  INTERMITTENT setting.

Mini Humidifier.jpg
When people are curious, here is a quick way to explain:

It is a mini humidifier that emits water with a little bit of mild air sanitizer added. The sanitizer is actually one that is used for disinfecting water when you go camping, and rinsing fruits and vegetables to prevent mold. It helps disinfect air, and has been tested directly on surfaces to destroy coronavirus.

Important notes: Application methods described on this page are based on theoretical assumptions. Real-world concentrations will vary greatly, depending on which chlorine dioxide/sodium chlorite product you use, how precisely the humidifier is functioning, and conditions in which you are using these. Verification of actual concentrations created requires checking with a chlorine dioxide gas detector (Example A, Example B) or monitor. (Be sure to select the "ClO2/chlorine dioxide" model when purchasing.)