Educational

Is disinfection by fogging adequate to safeguard business premises against COVID-19?

Judy Sunasky

While disinfection is a great idea, be aware that spraying disinfectants, also known as fogging, to eliminate the novel

coronavirus that causes COVID-19 should not be seen as a single answer to a business’s deep-cleaning requirements.

Fogging is an appealing option, especially because of its effective use in the food industry as a disinfection method for some time. Adopting methods of cleaning and disinfecting from the food industry is an excellent strategy in fighting the virus, but it is important to remember that fogging is never viewed in the industry as an all-in-one solution.

Food facilities use fogging as a final stage, following thorough cleaning and disinfection. These facilities and the health inspectors that audit them know that fogging alone will not successfully disinfect a space. It is just a layer of protection. Think of it as the hand sanitiser you apply. It can be extremely effective, but if you shake hands with sick people, or touch any surfaces they have touched and then rub your nose, it will be rendered useless.

Cleaning first is a critical step in your sanitation programme. A good cleaning protocol can remove as much as 80 percent of the viral load. You will want to complete your cleaning process before moving on to fogging.

Most importantly, before you even begin to fog, or clean for that matter, you must be sure that your staff are wearing the correct personal protective equipment (PPE). For cleaning and for fogging, wear closed shoes, ideally safety shoes, and overalls, gloves and protective eyewear. Additionally, before fogging, you must add a respirator – a mask is not adequate, nor is a face shield. The eyes must be fully protected from any of the fogging chemicals, which may also affect the operator’s lungs and breathing.

The area to be fogged must be prepared in other ways, such as removing all people (apart from the person executing the fogging) and pets. Cupboards should be opened and electrical appliances, air conditioners, fans and lights must be switched off. All windows and doors must be closed during fogging applications and while the fogging chemicals settle.

There are two fogging methods: using an aerosol can or a fogging machine.

Fogging, especially with a machine, is a specialised service and should be done by those who have experience in this technique, so choose a company with a proven track record.

When you use an aerosol fogger, the chemicals inside the can are prepared and ready for use. It is vitally important that you follow the instructions on the can as the instructions for each brand will differ. Pay special attention to the amount of space the single aerosol can cover. If used correctly, this is a convenient, often cheaper, way to disinfect a small area when fogging.

A fogging machine is a better option when a larger area needs to be covered. When using a machine, it is important that a suitable disinfectant is used. We do not recommend the use of bleach (sodium hypochlorite) as it is corrosive and not safe on all surfaces.

Also, alcohol-based disinfectants should not be used because the microparticles of alcohol may evaporate before landing on the surfaces that

Fogging, especially with a machine, is a specialised service and should be done by those who have experience in this technique, so choose a company with a proven track record.

need to be disinfected, defeating the purpose. However, aerosol foggers often use ethyl alcohol as a propellant, which has the bonus of creating an additional disinfecting layer.

Product selection is going to be vital for the success of your fogging exercise. You need to consider the chemicals to be used carefully as not all disinfectants are created equal.

Firstly, please choose a registered product. It’s just safer, and may be the difference between an effective disinfection process and one that does not actually work. Nobody wants to spend money on a fogging exercise that doesn’t actually do the job because the chemicals were not up to scratch. With a registered product you have peace of mind.

It is a legal requirement in South Africa for all products that are classified as disinfectants to be registered with the National Regulator for Compulsory Specifications (NRCS). The NRCS is an independent organisation established in 2008 to promote public health and safety, environmental protection and fair trade through developing and administering technical regulations for products. Products cannot be registered with the NRCS unless independent tests have been performed.

If you decide to operate the fogging machine yourself, you will need to find out how to use the product before you hit the pump trigger. Should it be diluted or used as is? This information should be on the product label. If it isn’t, contact the manufacturer for guidelines.

Each fogging machine is different, as is the method the person using the machine follows. The best way to ensure efficacy is to test after the fogging is complete.

This is best done by completing a swab test. An adenosine triphosphate (ATP) swab test will look for organic microorganisms, meaning if the test result is good your premises will be clear of a lot more than a coronavirus. Rest assured, if there are no surviving microorganisms, then a coronavirus has not survived either.

Fogging can be a useful tool in your arsenal for cleaning and disinfecting, but should never be used in isolation.

Judy Sunasky is owner and MD at Blendwell Chemicals. Blendwell offers a wide variety of cleaning products with a speciality in environmental and food-specific cleaning products. For more information visit: www.blendwell.co.za