CleanZone Sanitizing System FAQs

Ozone is a powerful agent for disinfecting. We’ve compiled some questions and answers you might find useful with regard to our CleanZone sanitizing system.

Locate the instruction label on the side of the CleanZone cart/station (shown below).

Make sure the LED light is GREEN. This indicates that the system is ready to use and any previous cleaning cycle has been completed.

  • Load your devices as usual into the system.
  • Be sure to fully close and lock all doors of the cart or station.
  • To begin the ozone cleaning cycle, press and hold the silver START button for approximately 2-3 seconds.
  • The LED will turn RED, indicating that the ozone decontamination cycle is in progress.   
  • DO NOT open the doors of the system at any time while the LED is RED. This will cause the ozone gas generated inside to escape too quickly into the room, potentially raising ozone levels near the cart/station.
  • When the LED light turns GREEN, the cycle is complete, and the devices are ready to be safely accessed.
  • The sanitizing cycle takes approximately 15 minutes to complete.

NOTE: As an added precaution, we recommend that users—especially those who may be more sensitive to smells or suffer from any respiratory-related issues—maintain a minimum distance of six feet from the CleanZone system during the cleaning cycle.

GREEN LED MEANS GO: Cart/Station can safely be opened and utilized

CleanZone operating instructions-green

RED LED MEANS STOP: The decontamination cycle is active, so don’t open the cart/station doors

Red LED showing active CleanZone cycle

Once the CleanZone system is activated, the device will generate ozone, a molecular compound consisting of 3 parts of oxygen (O3, otherwise known as tri-atomic oxygen). When ozone bonds with a virus, bacteria, or mold cell walls, it kills them. Once the disinfection process inside the cart or station is complete, the O3 will naturally dissipate into the room—the only byproduct is oxygen. Ozone gas has a very short lifespan and breaks down very fast.

Ozone has been used safely for years as a highly effective disinfectant. Ozone targets microorganisms and destroys them on contact. The FDA, USDA, and EPA have approved ozone as an antimicrobial disinfectant. It’s 3,000 times faster and 50% more potent than chlorine/bleach. Ozone kills many types of bacteria and even the common cold virus, leaving no chemical residue. Tests have also shown ozone kills 99.9% of pathogens on contact.

Decontamination is quick: Once the ozone generator is activated, sanitizing will be completed within a 15-minute cycle. Ozone is generated only during the first few moments of the process—the remainder of the generation cycle allows the ozone to be distributed throughout the contained space until it naturally decomposes and dissipates back into oxygen. When the LED indicator turns GREEN, the cart/station door may be opened to access the sanitized devices.

In the CleanZone system, ozone is only generated for a few moments at the start of the cleaning cycle. The ozone is contained within the cart/station enclosure to prevent ozone levels outside the cart/station from reaching levels high enough to be considered hazardous to users. The cart or station’s door(s) need to be closed and locked before initiating the decontamination process. Once the cycle is complete, the ozone dissipates very quickly and becomes oxygen again. Testing has shown that the entire sterilization cycle lasts approximately 15 minutes. When the LED light turns GREEN again, it’s safe to open the doors and access devices.

As an added precaution, we recommend users—especially those who may be more sensitive to smells or suffer from any respiratory-related issues—maintain a minimum distance of six feet from the CleanZone system during each cleaning cycle.

Yes, ozone has a somewhat familiar smell. When you are outside, right before a thunderstorm and particularly right after a lightning strike, that “pungent,” “electronic,” or even “clean” scent is ozone. This smell is the result of the electrical current splitting up the oxygen molecules. The fragrance (along with the gas) quickly dissipates and naturally converts back into oxygen.

The largest CleanZone cart can house up to 40 devices. Although the cleaning cycle only lasts around 15 minutes, we recommend running the system no more than once per hour, allowing excess ozone levels to dissipate entirely. Our factory testing has shown that it is possible to cycle the system more frequently and still stay within recommended guidelines. However, running more often or continuously in a traditional, enclosed classroom without proper ventilation is HIGHLY discouraged. We recommend these guidelines to prevent the room from reaching and maintaining a higher ozone concentration than the EPA’s recommended 0.08 ppm (parts per million).

Ozone has been used regularly as a disinfectant around the world for more than 150 years. Ozone’s effectiveness and its potential hazards have been well-documented. It has been used as a drinking water disinfectant since the turn of the last century. Like other disinfecting products (UV, bleach/chlorine, alcohol, etc.), ozone can be harmful if not handled properly. Ozone is a strong oxidizer; the ozone cart or station door should be locked during the entire sanitizing cycle, allowing the ozone gas generated to be contained and to dissipate safely back into oxygen. When the sanitizing process is complete and the LED indicator on the side of the cart turns GREEN, it is now safe to access and use the devices.

As an added precaution, we recommend users—especially those who may be more sensitive to smells or suffer from any respiratory-related issues—maintain a minimum distance of six feet from the CleanZone system during the cleaning cycle.

No damage will occur from the regular and recommended use of the CleanZone system. However, ozone is an aggressive disinfectant—prolonged or excessive use of any disinfectant may cause plastic or rubber components to become dry or brittle. We recommend checking annually on the condition of all rubber components such as charging cables, rubber feet, and cases. Be sure to replace any parts or cables which show signs of deterioration.

Porous materials such as books and thick fabrics are not ideal for ozone disinfecting. However, the CleanZone system can clean the exterior covers and edges of books, but may not penetrate the internal pages.

NOTE: Ozone is an aggressive disinfectant, and prolonged or excessive use of any disinfectant could cause materials such as paper or thick fabrics to become more dry or brittle.

No, the CleanZone system must be factory installed. However, your current EarthWalk carts may be sent to EarthWalk, where our skilled technicians can install the CleanZone system into your carts or stations. The CleanZone system is not compatible with all cart models, so contact EarthWalk Support for compatibility and retrofitting.

No, ozone is created without using any harsh chemicals. The system uses electricity and the air around it to isolate oxygen molecules to generate ozone (03) gas. The O3 gas has a very short lifespan and breaks down very quickly, converting back into oxygen.

The total lifespan of O3 gas in the atmosphere is under one hour. But it begins to dissipate as soon as it makes contact with any surface. The amount of ozone generated inside the controlled CleanZone space is minimal. Therefore, after the cleaning cycle has completed (approximately 15 minutes), opening the doors gives the O3 gas enough time to dissipate to safe levels. The only byproduct of O3 gas is pure oxygen.

NOTE:  O3 gas is heavier than air, so once the cleaning cycle has completed and the cart/station doors are opened, any remaining O3 gas will spill onto the floor and dissipate at floor level almost instantly. You may detect a mild odor of ozone, but it is not harmful.

The CleanZone generator does require some monitoring and minimal maintenance. The ozone generator’s lifespan and performance may be affected by several conditions; however, you can expect the generator to perform for approximately 1,000 to 1,200 cleaning cycles in most classroom environments.  The more frequently you use the CleanZone system, the faster it will need to be refreshed. When the system is appropriately generating ozone, it will produce the “pungent,” “electronic,” or even “clean” scent or odor of ozone.  If this odor drastically fades or is no longer present, the system needs recharging.

EarthWalk has a “CleanSwap” reconditioning program available to all CleanZone customers, enabling the user to simply remove and swap the depleted generator box for a new one. For more information on “CleanSwap,” contact our team at   

NOTE: No tools are needed to remove and replace the ozone generator box to perform the “CleanSwap” refresh. No end-user service should be attempted or completed on the CleanZone internal components; doing so (tampering with the generator box) will void all warranties on your EarthWalk CleanZone system.

The CleanZone system is programmed to run within the factory-installed, contained space inside our specific carts/stations. It generates only enough ozone for the particular interior volume of the cart/station where it has been installed. The system circulates the ozone gas inside the cart—you will hear the fan’s sound during each cycle—sanitizing all surfaces it contacts. Ozone is produced for a very brief time (less than two minutes), then it begins to dissipate very quickly. Given the volume of the space within the cart or station and the “contained” nature of its operation, the extent of any potential exterior exposure is minimal and falls safely within OSHA guidelines. Also, ozone is heavier than air, so after the decontaminating cycle is completed and the cart/station doors are opened, any residual ozone gas remaining will spill onto the floor and dissipate at ground level almost instantly.

NOTE: Be sure to fully close and lock all the cart or station doors before beginning the decontamination cycle.

NOTE: Do not open the cart or station doors at any time while the LED indicator light is RED.

NOTE: We recommend users—especially those that may be more sensitive to smells or suffer from any respiratory-related issues—maintain a minimum distance of six feet from the CleanZone system during the cleaning cycle.

Coronavirus (COVID-19) is a “novel” virus—as of today, no independent laboratory testing for its sterilization has been completed. The international medical community strongly believes that ozone treatment will be very successful in combating Coronavirus (COVID-19) based on the results achieved in destroying SARS-CoV-2 (responsible for COVID-19). SARS-CoV-2 is an enveloped virus, which means the structure of these viruses include a lipid envelope and are easily susceptible to destruction by disinfectants—including ozone. Ozone readily oxidizes the lipid envelope, changing its structure or destroying it. Other virus families are also killed by direct exposure via ozone to capsid proteins and nucleic acids; many studies have tested the efficacy of ozone in conjunction with the SARS virus. 

For reference, the SARS virus has a kill rate of 90% with ozone levels as low as 1.2 parts per million (ppm) within 7 minutes of exposure. CleanZone reaches levels of 10 ppm inside its enclosed space and provides an exposure/decomposition time of over 10 minutes. CleanZone is well within the 99% range for killing most viruses. 

Enveloped viruses are usually more sensitive to physicochemical challenges. In past studies, 99% of viruses have been damaged or destroyed after 30 seconds of exposure to ozone. Ozone destroys viruses by diffusing the protein coat into the nucleic acid core, resulting in damage to the viral RNA. At higher concentrations, ozone destroys the exterior protein shell by oxidation.

Yes, in most cases. Since ozone is a gas, the CleanZone system can circulate it throughout the cart or station; a fan begins to operate when the sanitizing cycle is activated. The ozone can permeate the internal space of items housed inside the cart/station, provided the items are not air-tight or sealed within air-tight cases or covers. For best results, if possible, leave the devices’ lids slightly open to allow for better ozone penetration of interior surfaces.

Ozone is a natural yet powerful sanitizer. When ozone bonds with a virus, bacteria or mold cell walls, it kills them—leaving no chemical residue.

EarthWalk has done extensive research and development into effective sanitation of devices in our carts and stations. What sets us apart from other providers is that we incorporate ozone as the sanitizing agent for laptops, Chromebooks and tablets. Other companies use UV lights (typically UVC). So what’s the difference?


Ozone structure icon UV light graphic
Ozone, a powerful oxidizer, is produced by a generator and kills organisms UVC rays are generated by a UV lamp and they inactivate microorganisms if they have sufficient contact time
Ozone is a dense gas, which permeates all areas within the enclosed space and reaches all areas of your Chromebooks, laptops & tablets Devices will only get sterilized where the UVC light is able to reach surfaces
While ozone gas can be a respiratory irritant, best practices minimize any exposure when the system is deployed in the contained cart UVC units can seriously damage eyes and skin if exposed during the cycle
Ozone sanitizing technology is cost-effective and higher quantities of devices can be cleaned at one time UVC sanitizing technology can be costly (particularly having to install enough lights to reach all device surfaces)
When the sanitizing cycle is complete, the molecules dissipate back to oxygen within minutes UVC light degrades plastics (such as charging cables and other plastic components)


James B. Hudson, Manju Sharma and Selvarani Vimalanathan, “Development of a Practical Method for Using Ozone Gas as a Virus Decontaminating Agent.” The Journal of the International Ozone Association, 2009, Volume 31, Issue 3.

“Know Your Ozone: it’s Good, Bad and Bacteria-Blasting.” American Council on Science and Health, Accessed October 2020.

Gérard V. Sunnen, M.D., “COVID-19, MERS, SARS and Other Emerging Coronaviruses: Theoretical Considerations and a Proposal for Critical Care Parenteral Blood Ozonation.”  Copyright 2020.

“Ozone vs. Coronavirus: Ozone’s Efficacy as a Virucidal Disinfectant.” Accessed October 2020.

Contact us for more details!

Click the button below to find an EarthWalk rep who covers your area.

Find a rep button


Toll Free:  1-888-213-4900 (U.S. domestic only)
International: +1-703-393-1940

Contact Us Online