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Infection control methodology #3: Disinfection

Updated: Jul 20, 2020

It’s time for the third blog in our series on infection control methodology. We’re proud of our simple but rigorous approach: test, clean, disinfect and test again. Right now, this is crucial in controlling the SARS-CoV-2 coronavirus which causes Covid-19. In previous blogs in this series, we’ve looked at the testing and cleaning processes. This time round, it’s the turn of disinfection. We’re going to compare some different disinfection systems and look at which ones might be best suited for your workplace.

A closer look at viricides

After testing and cleaning a surface, we need to apply a viricidal disinfectant certified to be effective in disabling viruses such as SARS-CoV-2. It’s important to note that some disinfectants are antibacterial rather than antiviral. In many cases, the effectiveness of these agents at eradicating coronaviruses is unproven. Therefore, we choose viricidal disinfectants that have been demonstrated to be effective, including quaternary ammonium or chlorine compounds.

However, these are potentially harmful chemicals. If used incorrectly or too frequently, they can cause long-term health issues, as well as discolouring the surfaces to which they’re applied. We’re currently evaluating environmentally friendly alternatives to these chemicals. Some have proved effective with shorter contact times, and they’re much less harmful to health and the environment.

Infection control methodology means choosing the right disinfection system

As well as the correct choice of viricide, it’s important to think about the best delivery system for applying disinfectant to surfaces. In most cases, we recommend ULV (Ultra Low Volume) fogging as part of a deep cleaning regime to address any potential SARS-CoV-2 contamination. ULV Foggers deliver the active product at droplet sizes ranging from 10 to 120 microns, allowing extended contact times to provide ongoing protection. For this reason, ULV Foggers should only be used with products that are safe for use in the presence of people when adjusted to levels below 80 microns.

We supplement ULV fogging with a ‘spray and wipe’ process, to focus on high-contact areas easily touched by people. Spray and wipe is conventionally used with targeted electrostatic spraying, but we’ve found that ULV fogging is more effective for overall effective infection control. Electrostatic spraying uses a larger droplet size, which allows disinfectants to dry out in two to three minutes. That is short of the vast majority of contact times recommended on product labels, which range from five to fifteen minutes.

Disinfecting an entire room in one go

Whole room fine misting or fogging systems have been gaining traction, especially in the health care sector. This process involves filling an enclosed room with one microdroplet size mist of products such as hydrogen peroxide. This process may take several hours. The hydrogen peroxide mist will reach all areas of the room, including areas that conventional ‘spray and wipe’ protocols may miss.

An advantage of whole room misting is that the disinfectant may have greater surface contact time. However, all surface disinfection products provide relatively poor soil removal (including biofilm). Furthermore, there is no residual cleaning or protection once they dry out. We only consider this method in a small number of specific circumstances; and even then, we consider other methods as being more practical and effective at dealing with SARS-CoV-2.

Shining ultraviolet light at the problem

Certain wavelengths of ultraviolet (UV) light can also be used to disinfect objects and surfaces. UV light is of course produced by the sun, as well as by special lamps. There are three types of UV light, which are distinguished by the wavelength of the light: UVA, UVB, and UVC. The most energetic of the three is UVC. It’s this energy that destroys the genetic material inside viruses and other microbes, so it can be used for disinfection. However, UVC’s high-energy light is also extremely dangerous to humans, as it can quickly damage the eyes and burn skin. Its application therefore needs care and the appropriate PPE (personal protective equipment).

Like most other processes, application of UVC has not been clinically tested specifically against SARS-CoV-2, even though it has been proven to destroy related coronaviruses. UVC lamps and robots are commonly used to sanitize water and objects such as laboratory equipment. UVC is used in spaces such as hospitals, and on buses and aircraft. Therefore, although we do use UVC as part of a deep cleaning process, we only deploy it in very specific circumstances.

Disinfection is the job of specialist cleaning teams

Whichever disinfection system we use, we can guarantee that you’ll get excellent service. Our specialist cleaning teams are properly prepared and equipped to get the job done. Whether we’re undertaking a regular deep clean, or providing first response cleaning support, we’ll help you to keep your workplace safe. Together we’ll get through this pandemic.

Find out more in our free Coronavirus Fact Sheet. We bust some social media myths about the virus and tackle the misinformation head-on – as well as providing some useful do’s and don’ts. Register to download our fact sheet for free.

Contact one of the team today to find out more about our infection control methodology, and in particular, which method of disinfection will be best suited for your workplace.

Post by Shaun D. Doak

Shaun is the CEO of React Group plc., a business dedicated to specialist cleaning, hygiene and decontamination. He is deeply committed to making sure that every one of our company’s clients receives the highest possible level of service. An expert in HVAC and commercial and industrial cleaning methodologies, Shaun has extensive experience in the facilities management and renewable services sector.


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