World Health Organisation: Fogging is ineffective for coronavirus (COVID-19)

The World Health Organisation has deemed fogging ‘ineffective’. In indoor spaces, routine application of disinfectants to environmental surfaces by spraying or fogging (also known as fumigation or misting) is not recommended for coronavirus (COVID-19). One study has shown that spraying as a primary disinfection strategy is ineffective in removing contaminants.

What is fogging?

Fogging is a touch-less disinfection system that can be defined as putting small particles of hydrogen peroxide solution into the air and maintaining a silver hydrogen peroxide vapour throughout the space being fogged.

How does fogging work?

The fogging machine, or fogger as it is sometimes called, is a versatile piece of equipment that uses a fine spray to apply a chemical solution, often used for pest control, restricting the growth or mould or odour control. It is becoming increasingly popular as a means of sanitising surfaces.

The fogger uses pressure to create a fine mist (or fog) which is applied to the targeted area, the spray density typically being moderated by a manual valve to ensure the optimum effect. Depending on the type of fogger being used, it is possible to spray up to 12 metres, enough to cover a large room. The fine fog can reach into corners and difficult areas and may also penetrate porous surfaces.

Chemicals should be used with care though, as the spray or mist can linger in the air, so time should be allowed for the solution to settle and do its work. Keeping an area clear of people when treatment is underway protects any operatives from inhaling any unpleasant chemicals.

Moreover, spraying disinfectants can result in risks to the eyes, respiratory or skin irritation and the resulting health effects. Spraying or fogging of certain chemicals, such as formaldehyde, chlorine-based agents or quaternary ammonium compounds, is not recommended due to adverse health effects on workers in facilities where these methods have been utilized.

Spraying environmental surfaces in both health-care and non-health care settings such as patient households with disinfectants may not be effective in removing organic material and may miss surfaces shielded by objects, folded fabrics or surfaces with intricate designs. If disinfectants are to be applied, this should be done with a cloth or wipe that has been soaked in disinfectant.

Furthermore, devices using UV irradiation have been designed for health-care settings. However, several factors may affect the efficacy of UV irradiation, including distance from the UV device; irradiation dose, wavelength and exposure time; lamp placement; lamp age; and duration of use. Other factors include direct or indirect line of sight from the device; room size and shape; intensity; and reflection.
Notably, these technologies developed for use in health-care settings are used during terminal cleaning (cleaning a room after a patient has been discharged or transferred), when rooms are unoccupied for the safety of staff and patients. These technologies supplement but do not replace the need for manual cleaning procedures.

If using a no-touch disinfection technology, environmental surfaces must be cleaned manually first by brushing or scrubbing to remove organic matter. Spraying or fumigation of outdoor spaces, such as streets or marketplaces, is also not recommended to kill the COVID-19 virus or other pathogens because disinfectant is inactivated by dirt and debris and it is not feasible to manually clean and remove all organic matter from such spaces. Moreover, spraying porous surfaces, such as sidewalks and unpaved walkways, would be even less effective. Even in the absence of organic matter, chemical spraying is unlikely to adequately.

Furthermore, streets and sidewalks are not considered to be reservoirs of infection for COVID-19. In addition, spraying disinfectants, even outdoors, can be harmful for human health. Spraying individuals with disinfectants (such as in a tunnel, cabinet, or chamber) is not recommended under any circumstances. This could be physically and psychologically harmful and would not reduce an infected person’s ability to spread the virus through droplets or contact. Moreover, spraying individuals with chlorine and other toxic chemicals could result in eye and skin irritation, bronchospasm due to inhalation, and gastrointestinal effects such as nausea and vomiting.

What are the disadvantages of fogging?

Since fogging relies on filling air inside a room or other area being treated with disinfectant mist, it is difficult to ensure proper coverage is achieved on all surfaces. This uncertainty makes it difficult to ensure cleaning dwell times required by disinfectant manufacturers for effective applications are met. Additionally, the application process is relatively slow compared to other disinfectant solutions.

What makes Pure Decontamination different?

Our disinfection and decontamination equipment uses the power of airless spraying to deliver the highest speed and productivity when applying disinfectant materials. Maintenance professionals now have the flexibility to chose from a variety of sprayer sizes to match specific job requirements. In addition to providing unmatched application speed, the higher flow rates and larger material reservoirs also reduces operator fatigue over the course of disinfecting applications.

Consistent Atomization & Coverage

Our disinfection and decontamination equipment delivers the proper atomization required to quickly and consistently coat surfaces to disinfect and sanitize efficiently. Models come equipped with interchangeable tips and adjustable pressure to achieve the desired spray pattern and coverage required to meet chemical dwell time requirements.

Consistent Disinfectant Coverage From Edge to Edge

These new sprayers provide consistent application coverage that can be delivered in either high production or fine spray methods, depending on the needs of the job. These dedicated airless sprayers provide the fastest application method for effectively applying disinfectants to surfaces.