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

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Mould spores are not visible to the human eye and are only manifested when conditions allow them to “flourish” and 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; 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, although these typically have to be ingested (eaten) to cause damaging effect.

There are also syndromes, forms of hypersensitivity, that have been associated with moulds as the potential allergen(s). By their very nature they present with non-specific symptoms that can be difficult to measure demonstrate objectively. The symptoms of these hypersensitive reactions can be similar across different types of allergens too. They can be wide ranging and caused by multiple potential sources. This makes diagnosis and treatment very difficult, if not impossible, for physicians.

Conditions for growth and removal

Where mould growth is seen in the workplace, it indicates that conditions are occurring for spores to germinate and grow. These need to be investigated, traced and removed.

The most common problem causing mould growth in workplace environments (and homes) is damp (in walls and other surfaces), excessive humidity for prolonged periods (in areas such as washrooms) and/or poor ventilation. Each of these causes can be identified reasonably easily and practical solutions can be applied. The mould can be removed by deep cleaning with an appropriate disinfectant – remember your COSHH requirements too.

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

What is the legislation?

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 with recognised standards, so that conclusions can be drawn about the quality of indoor air. Relative humidity and if necessary, damp testing can also provide information about the local environment.

The Control of Substances Hazardous to Health (COSHH) Regulations 2002 have also been cited in relation to mould. While duties exist in relation to biological agents and “germs” that cause disease (such as those causing legionellosis and leptospirosis), mould is not specifically identified (other than in relation to the other type of mould and ferrous foundry particulates). Remembering than may of the aliments caused by moulds are non-specific hypersensitivities (so it can be difficult to pinpoint cause) the general provisions of the regulations could have application in certain circumstances.

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 target and identify the source.

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.

This guide is of a general nature; specific advice can be obtained from Assurity Consulting by calling tel. 01403 269375 or by email info@assurityconsulting.co.uk