Your industry news - first Number 1 for Recruitment
We strongly recommend viewing Cleanzine full size in your web browser. Click our masthead above to visit our website version.
Mould 2 ...
Mary de Cobos of Futureclean Assured Systems, follows up her previous article on cleaning mould, which featured in last week's Cleanzine...
It is essential that the health & safety issues are considered and in this article we will discuss these in greater detail.
Any cleaning company will almost certainly come across mould deposits and their removal even if it is only in someone's bathroom; however moulds will always be present in hidden places, damp ducting, after fire and flooding, in a damp atmosphere and always where some water ingress is to be found. Mould is even to be found in diesel fuel tanks as part of biofilm contamination and it is one of the big problems on ships. So it's widespread and the air that you breathe is full of mould spores.
In UK we do not usually get extremely heavy deposits of 'toxic mould' with which US housing is often afflicted - especially in the very warm damp areas of Florida, Louisiana, Georgia, etc.; however, care is always needed whenever mould has to be removed.
It is a health hazard causing sinus and breathing problems (including farmers lung from mouldy hay and corn) so, now you know what you are facing, here's how to deal with it.
PPE: Mould is insidious in that it is not always identified amongst general dirt, but by smell it can be noticed.
The correct Personal Protective Equipment for cleaning mould is at least a mask covering nose and mouth, and goggles for eye protection as well as the usual PPE for general cleaning work. You always need these. Dried mould sporifies and disperses into the atmosphere if it's disturbed. Then of course you will breathe it in, so use nose and mouth protection. For very heavy mould deposits and always in enclosed spaces, it may be necessary to use full breathing apparatus.
First step: Look at the area to be cleaned. A good level of fresh air ventilation should flow through the area and a dehumidifier will remove much of the humidity - however a damp, mould-contaminated enclosed area - a void, ducting attics or cellars for example, will have a considerable amount of drying damp mould on a damp surface. This will always appear after flooded areas or surfaces have dried out. To clean the area, it should be completely free of rubbish, (and furniture, etc. where possible). Barriers or some form of containment should seal off all areas subject to mould contamination.
Cleaning process: it is essential to get the job done as fast as possible. There are two possible ways to do this: some heavy mould deposits may need sanitising treatment (see previous article) before cleaning. If this is the case, coat the sanitiser well onto the surface and leave the sanitiser to work for 24 hours before cleaning the surface.
Wash down the surface with a hot water and detergent (using any good commercial hard surface detergent) solution, making sure that you use abrasive cloth or a brush and work the solution well into the surface (mould may be deeply embedded within the surface). The surface is properly clean when the rinsing water is clean.
Rinse the surface well and dry it well. Once the surface is cleaned and dried, coat with the sanitiser again and leave it to dry.
What to look for: mould will work into cracks (see bathroom grout for example) and you should be aware of this. It may never be just a smooth surface clean, therefore the sanitiser coating should be quite thick and a residual sanitiser is a better choice.
On very contaminated areas and surfaces:
Very heavily contaminated surfaces and areas may need containment via a temporary tent to seal the area off. The use of negative air machines or air scrubbers is needed to maintain pressure in the tent and the air is ducted through filters directly into the open air. An airlock system is set up for access to the area.
Finally: make sure that all cleaning equipment is cleaned and sanitised after use. Consider that leaving surfaces wet - after cleaning carpet for example - will always trigger mould growth; this why anyone cleaning wet ducting from kitchen exhausts should always dry the ducting well and then sanitise it. It is also the reason why dry ducting is only ever dry cleaned - mould colonies are always an indicator of water ingress in dry ducting.
Mould will always develop in a flooded carpet after drying, the best course of action here is to wash the carpet with carpet cleaner as you would on an ordinary carpet clean, dry it well and treat it with sanitiser.
Mould will always grow again in the same place, so be aware of this. The absolute cure is to keep the surface dry and well cleaned at all times.
25th September 2014