Following on from his piece on Fogging last year in Tomorrow’s FM Magazine, James Nayler looks at the difference between Fogging and Electrostatic Spraying, the PPE required, and which option should be used when…
A lot of businesses are now taking extra precautionary steps to ensure the spread of Coronavirus is reduced. After a thorough clean of potentially contaminated surfaces, we are seeing fogging or electrostatic spraying applied more regularly than before.
So, what are the differences? And how do we decide which one to use?
The basic principle of fogging is to reach high level surfaces, the undersides of surfaces, ceilings and other areas that can sometimes be missed or overlooked. A fog has to consist of tiny micron particles that are less dense than the air around it, which naturally allows the fog to rise and target the high-level surfaces.
We are regularly asked questions by customers around fogging, with the most common being, “What are the PPE requirements whilst I am fogging?”, and the answers vary substantially depending on the type of machine is use.
A fogging machine can be either a stand-alone piece of equipment or a handheld device. If using the stand-alone option, the machine is left in the middle of a room and does not require the need to be moved. This type of machine is isolated by a source of power (either electric or pneumatic) from outside the room and will run for the programmed time.
Unfortunately, a lot of people are mis-lead into believing they need head to toe PPE when fogging this way, and you do not! The reason being is – if conducted properly – you are not in the room whilst the fogging is taking place, nor for at least 60 minutes post fog.
However, with a handheld application, PPE requirements are much greater as the user is in the same room as the fog, therefore, putting themselves at greater risk of contact with the sanitiser by ways of inhale, ingest, skin and/or eyes. As a minimum, we would recommend suitable eye, body, hand, and respiratory protection. You will be able to find advice on PPE from your local provider.
When a room is fogged, windows should be sealed, electronic equipment isolated and bagged off, and all doors should remain closed. A more detailed summary of fogging can be found within the ‘Facts About Fogging’ piece found in the August edition of Tomorrow’s FM.
The application and PPE requirements are very similar to that when carrying out handheld fogging.
The basis of Electrostatic Spraying is similar to fogging, but there is an important additional process that takes place. At the tip of the sprayer, as the sanitiser leaves, it is positively charged with an electrode.
As nearly every surface that we aim to sanitise has a negative charge, the positive charge that is applied therefore means that the negative surface magnetically attracts the positively charged sanitiser. This in turn causes a “wrap around” affect, almost guaranteeing complete surface coverage.
The diagram below shows this:
Compare that to a handheld fog, that is not positively charged, directed at the same surface:
Electrostatic Spraying vs Fogging
If targeting specific areas in-between client meetings, such as tables & chairs, or individual toilet cubicles throughout the day, then electrostatic spraying would be the preferred option as this method is prone to less atomisation of sanitiser and is a lesser risk to those in the same vicinity.
Fogging, however, is better suited to those areas that are vacant after hours, such as office buildings, restaurants, gyms etc. The benefits of fogging ensure complete sanitiser coverage of all surfaces rather than specifics.
It is important that you choose the correct form of disinfection for your business, and the health of your employees and customers. Take extra precaution when risk assessing the environment to be sanitised before deciding. In either application, the efficacy of the sanitiser is the same.