[Skip to content]

FM World logo
Text Size: A A A
27 April 2018
View the latest issue of FM
Sign up to FM World Daily >
FM World daily e-newsletter logo



Alongside their conventional cleaning and hygiene practices, office and facilities managers now have a secret weapon to help keep at bay outbreaks of infections such as norovirus – Ultra Low Volume (ULV) fogging. Luke Rutterford, technical manager at Rentokil Specialist Hygiene, explains.


13 March 2017 | Luke Rutterford

Figures from Public Health England show that more people this year were struck down with norovirus during the Christmas season than in any of the past five years – the infection rate figure was 71 per cent higher than for the same period last year. 

Norovirus (or ‘winter vomiting bug’) has a very low infectious dose – one only needs to have a few viral particles to become infected. Regular cleaning and good employee hygiene play a vital role in preventing the spread of such illnesses, but if an outbreak takes place, to get the site back to normal as fast as possible there is Ultra Low Volume (ULV) fogging.

1. What is ULV fogging?

Even with a regular cleaning regime, dirt, grime and bacteria can build up in the premises, particularly in hard-to-reach places. 

ULV fogging is a technique that treats large areas in a short space of time by generating a visible mist formed of tiny droplets of disinfectant measuring 5-50 microns in diameter. 

2. Why is ULV fogging used?

The droplets of disinfectant used in ULV fogging ensure maximum coverage and a fast drying time, providing a quick and effective treatment for businesses. The process is also commonly used in large spaces such as office facilities, hotels, or in the food industry to quickly sanitise areas, including soft furnishings such as couches and curtains, that are hard to fully cover with manual cleaning alone. Ultimately, it helps keep the downtime for a business to a minimum. 

3. How does it work?

Studies show that using ULV fogging significantly reduces the number of potentially harmful pathogens, as it can cover areas that manual cleaning can’t reach. The fogging technique can also include a disinfectant with ‘Reactive Barrier Technology’ to keep areas sanitised for long periods. This is more effective than commonly used bleach-based cleaners, which kill pathogens at the time they are applied, only for the surface to be immediately recontaminated with viral particles from someone’s hand. With Reactive Barrier Technology, pathogens that land on the surface are deactivated so you get a far greater level of protection to break the cycle of infection. This is particularly effective in stemming the progress of an outbreak. 

ULV fogging is carried out by a trained specialist hygiene technician outside normal operating hours or while the facility is empty. The technician uses a specialised ULV fogging machine and a disinfectant solution that has been carefully chosen, tested and validated to ensure it is the most effective against the target pathogens and suitable for the particular environment.

4. What else do FMs need to know?

It is important for staff with norovirus or other illness symptoms to notify their workplace and stay away from work until at least 48 hours after the symptoms have ceased, so that it is not spread. If staff become ill, or report back complaining of possible symptoms that are symptomatic of gastroenteritis then a rapid-response fogging of a high-level disinfectant is highly recommended.  

It is always desirable to remove an infectious reservoir before it becomes an outbreak. This proactive approach, coupled with deep cleaning, also helps to demonstrate due diligence and goes a long way to ensuring compliance with workplace health and safety standards.

5. A final wipe…

Ultimately, both routine cleaning and deep cleaning are essential for premises to remain operational, hygienic and compliant, as is a thorough understanding of the basics of personal hygiene. ULV fogging is one of the key weapons in the arsenal for specialist cleaners to help keep your facility outbreak-free.

If you’re unsure about how regularly your premises require deep cleaning, or which services are required, then consulting a professional who can conduct a hygiene audit can be helpful in creating a suitable strategy. 

Luke Rutterford is technical manager at Rentokil Specialist Hygiene