What do I need to know about mould in the workplace?

What are mould spores?
Mould spores are found everywhere in the environment including on surfaces in the workplace. It is unreasonable to expect a normal workplace to be “free from” mould spores. Specific environments may need to be clinically clean for example, hospital operating theatres, vaccine production facilities and some food production plants. Mould spores are not visible to the human eye and are only manifested when conditions allow them to flourish to produce a visible fungus growth such as, the blackening that occurs in damp, poorly ventilated bathroom environments or the growth that appears on stale bread.

What is their significance?
There are moulds that are known to cause disease such as, Farmers’ lung associated with moulds in hay, Compost lung associated with moulds in compost, similarly Mushroom workers’ lung, and Malt workers’ lung associated with contaminated barley. These are clinical conditions that are confirmed by chest physicians who will make the diagnosis and will prescribe treatment. Similarly, there are specific fungi that are poisonous to human beings but these have to be ingested to cause damaging effect.

There are also “syndromes” that have been proposed to be associated with moulds when cited as potential allergens. By their very nature they are present with non-specific symptoms that are difficult to measure and very difficult to demonstrate objectively. The symptoms of problems with allergens can be similar across different types of allergens. They can be wide ranging and can be caused by multiple potential sources, as any material can potentially cause a hypersensitivity (allergic) reaction in an individual person. This makes diagnosis and treatment very difficult, if not impossible for physicians.

Conditions for growth and removal
Where moulds are manifested in the workplace, it is an indicator that there are conditions provided that allow for their growth. These conditions should be traced and removed. The most common problem causing mould growth in usual workplace environments are excessive damp in walls and other surfaces, excessive humidity for prolonged periods in areas such as washrooms and/or poor ventilation of the workspace. Each of these causes can be identified reasonably easily and practical solutions can be applied. The mould can be removed by deep cleaning with a biological disinfectant.

When these conditions for the growth of mould are removed, the re-appearance of the mould is very unlikely. Where the problem has persisted for a long period of time, the removal of the mould is sometimes challenging because the structures of the mould growth can penetrate deep in to surfaces, making them difficult to remove. Several cleans may be required if mould reappears.

What is the legislation on this area?
In the UK, the Workplace (Health, Safety and Welfare) Regulations 1992 recognise the requirement for adequate ventilation of a workplace by providing “a sufficient quantity of fresh or purified air.” Recognised measures that this is being achieved are by testing for the levels of known polluting gases (for example carbon dioxide and carbon monoxide), dust levels and levels of general bacteria. These can be compared with the levels in the outside air and also with recognised standards, so that a conclusion can be drawn about the quality of indoor air.

It is only when a specific clinical condition with a known pathology is diagnosed by a medically qualified physician that more detailed investigations are recommended with regard to moulds. This is because in this case the specific cause of the illness is known and the specific sampling technique can be employed to correctly identify the source.

This guide is of a general nature; specific advice can be obtained from Assurity Consulting. Assurity Consulting is the UK's leading independent compliance consultancy specialising in workplace health, safety and environmental solutions. We have over 30 years' experience of helping customers of all sizes, from across all sectors, manage their compliance responsibilities, making sure that their organisation is compliant, their employees are safe, their processes are cost effective and their management team is in control.

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