Fogging as a sanitisation technique

of you. So maybe it’s not that dramatic, but customers want to feel like they can sense what’s up. They walk through the commercial area of a hotel and they see the frequent cleaning with a well-known product of high-touch areas in the lobby.”

As part of that push for more transparency, the Hilton housekeeping procedures will include the placement of a room seal on the door to indicate that a room has been cleaned and left vacant since.

More sanitising tools for guests

Marriott is stocking guest rooms with disinfecting wipes and installing more hand-sanitiser stations in communal areas of its hotels.

“Marriott is also evaluating adding partitions at front desks to provide an extra level of precaution for our guests and associates and is working with supply chain partners to make masks and gloves available to associates,” a company statement said. Hilton is adding stations of disinfecting wipes in “key high-traffic areas,” including at elevators. But it’s also strategically subtracting: Hotels will remove pens, paper and the guest directory from rooms, with digital alternatives “available upon request.”

Contact-free check-in and room access

With social distancing so pivotal in preventing COVID-19’s spread, reducing contact with others is a priority. For hotels, that means tweaks to the check-in process are, too. More than 3 200 Marriott hotels are offering guest check-in and room access through their smartphones. Those guests can also use their phones to order room service or make other hotel requests.

There are various factors spreading its appeal. As in other areas of cleaning, the progress made in developing new chemical treatments has been remarkable. Historically, various chemicals including formaldehyde, phenol-based agents and compounds of ammonium have been used in fogging. Many had not been properly tested for potential effects on human health, some were toxic and others even damaged materials they came into contact with.

In recent times, clients, the public and service providers have been made more aware of the risks of germs and are, therefore, exploring better weapons in the war against infection. This article by Ashley White, Commercial and Safety Manager at cleaning and FM services specialist Nviro, demystifies fogging as a sanitisation technique.

Chemical or bio-fogging has been around a long time as a way of sanitising interior spaces in buildings. But what once was a highly specialised (and costly) cleaning technique for clean rooms, hospitals and the food-processing sector is now seeping into the mainstream.

Advances in biocidal technology have bypassed these problems so that biofogging is now known to be both safe and effective. In practical terms, not only is it now far more straightforward to carry out fogging, we can demonstrate how effective it is through simple before and after tests, using ATP (adenosine triphosphate) monitors. The other big factor is the growing demand for infection control and enhanced cleaning services. As a society we are now all too aware of the risks posed by the winter Norovirus vomiting bug, MRSA infections in hospitals, and the less regular but potentially lethal swine and bird flu pandemics. At times of heightened risk, hand sanitisers moved from hospital entrances into corporate offices, and are now increasingly commonplace.

Hilton, meanwhile, is expanding its Digital Key service, allowing guests to check-in and enter their rooms using their smartphones.

Employee health precautions

Under its new initiative, Hilton workers will “be provided with personal protective equipment (PPE) and enhanced training,” the chain said. Marriott says it is “working” to provide masks and gloves to its employees; as an extra barrier for staff and guests alike, it is also looking into adding partitions atop its front desks. As for other countries? Hotels in Singapore, for one, are abiding by the government’s ‘SG Clean’ certification programme, which mandates temperature and health screenings for employees.

Managing these risks falls increasingly on the facilities manager, in particular where they serve large employers. They understand the impact on their business of high levels of sickness, which runs to hundreds of millions of pounds each year in the UK. The employee well-being agenda has focused further attention on how the workplace is serviced, and on the importance of cleaning, indoor air quality and hygiene.

From schools and universities to ferry terminals, premises managers are responding to these higher expectations and their organisation’s duty of care to staff, students, passengers and everyone using their facilities.

As well as the threat of disruption to any organisation and financial loss to business, there is the risk of reputational damage too, especially if the response to an outbreak is slow or ineffectual.

Parallel to these developments, the more enlightened FM and cleaning service providers are expanding and enhancing their capabilities to support FMs and their goals, including more healthy workplaces.

What is fogging and how does it work?

Fogging is somewhat misleading as a term as the most common form does not create a fog as such. Chemical or wet fogging produces a fine mist, whereas dry fogging – more often used where there’s a lot of electrical equipment – does fill the room being treated with smoke.

Both methods operate on the same principles

The biocide particles in the mist or fog are so small that they remain suspended in the air long enough to kill airborne viruses and bacteria. The biocide also eliminates pathogens on surfaces, including ceilings and walls as well as furniture and floors.

An advantage with fogging is that the sanitising agent reaches areas that may be difficult to clean with other techniques. Penetration into some nooks and crannies may be limited by obstacles, but in most cases it’s not necessary to move furniture or equipment around before or during the cleaning process.

Previously, the chemicals used in fogging could adversely affect materials such as plastic, fabrics and metal – causing corrosion over time – this is no longer a concern.

Is fogging practical and safe?

The fogging process is rapid and efficient. FMs will probably be aware that formerly, an area might be sealed off for days at a time for fogging. Now sanitisation takes a matter of minutes. To avoid disruption and risk of allergic reactions, areas do need to be clear of people. So it should be done outside of working or opening hours – overnight, for example.

While the biocide is not toxic, there is always a risk of allergic or other reactions for those present during the fogging operation. A responsible contractor will ensure that staff wear the recommended personal protective equipment (PPE) for the agent used.

We favour a water-based anti-microbial that is non-hazardous, clear and odourless, non-corrosive, harmless to the environment and requires no rinsing. No special requirements apply either for protection against spillages or during handling or storage.

Can it be effective?

An effective biocide will target a wide spectrum of microbes and the results of testing bear out the claims that chemical fogging is capable of eliminating all pathogens.

For example, we recommend a solution using four different biocides so that a bacterium with resistance to one agent will be eliminated by the others. This biocide is effective against a wide range of microbes, including E. coli, MRSA, C. difficile, listeria, salmonella and Legionella pneumophilia.

Of course, the mist must reach the target areas and in sufficient quantities to sterilise surfaces. Evidence strips are used for this purpose.

And the evidence from our monitoring is that fogging gets to work immediately and the benefits are surprisingly enduring.

How do you test?

Cleaning standards should always be monitored. When it comes to sanitisation, performance needs to be measured scientifically. It’s now relatively simple to do this by testing for microbes using a hand-held monitor that measures ATP. Moreover, FMs can share this information with senior managers, including those responsible for HR and occupational health, to justify cleaning spend.

The ATP molecule is found in and around living cells. It’s used as a direct measure of biological concentrations and health. A luminometer gives us a reliable indication of ATP levels (see image).

Testing is as easy as ATP

A luminometer uses a naturally occurring firefly enzyme called luciferase that reacts with ATP. The light produced by this reaction is directly proportional to the amount of ATP present in the sample.

In layman’s terms, this means we can accurately gauge the concentration of living cells on a surface. Without sending off a swab to a microbiologist for analysis, you can’t tell what these cells are, and most will be harmless. For example, it is not unusual for a human hand to produce a count of between 500 and 800.

But this form of monitoring is a far more reliable indicator of cleanliness than relying on visual inspections, smell or cleaning task checklists.

The steps involved in an effective ATP testing regime are to: • Identify control points: a range of direct and indirect contact points, including areas that are easier and harder to clean. • Clean surfaces to the specified standard of the daily sanitation programme – and perform a deep clean in advance of fogging. • Conduct an ATP test at each location. If possible, take 5–10 repeat tests over several days. • Determine the pass limit by calculating the average reading for each point. • Determine the fail limit: multiply the pass limit by three. • Determine the caution zone: this is the range between the pass and fail thresholds.