Legal Overview

The Control of Substances Hazardous to Health (COSHH) Regulations 2002 (revised 2013) refers to all fungi and moulds as asthmagens. (COSHH Regulations fall under the Health and Safety at Work Act 1974.) The Health and Safety Executive (HSE) publication “The Approved List of biological agents” (revised 12 July 2021), supports COSHH who list 8 genera of moulds, with potentially hundreds of species as hazardous to human health, under the same classification for Asbestos.

Health Concerns

The growth of fungi and mould on materials in the built environment can affect human health, depending on the extent of growth, the length of exposure and the health status of the exposed occupants. Most people are familiar
with the term “toxic black mould” which refers to stachybotrys chartarum and the respiratory infection Aspergillosis, caused by the inhalation of aspergillus mould spores. NHS cites that damp buildings can cause the condition which affects the lungs and causes breathing difficulties. The health risk is highest for vulnerable people such as those with a pre-existing lung condition, such as asthma, cystic fibrosis or chronic obstructive pulmonary disease (COPD), those with a weakened immune system, for example, if you have had
an organ transplant or are having chemotherapy and those who have had a severe flu or coronavirus (COVID-19) and need artificial ventilation. The human immune system is not fully developed in children under 8 years old and weakens in adults over 70 years old, making them more susceptible to respiratory illness caused by mould. It is important to be aware that air currents can easily carry spores over long distances; contaminants entering ventilation systems in ‘high risk’ facilities such as schools, retirement homes and health care facilities can cause a serious outbreak of disease.

IICRC (Institute of Inspection, Cleaning and Restoration Certification)

There are no specific mould remediation guidelines or acceptable exposure limits specific to the UK. The IICRC is the only organisation recognised internationally to produce a standard and reference guide for professional mould remediation. The ANSI/IICRC S520:2015 describes the material science, protocols and techniques to be followed and the precautions to be taken when performing mould remediation in residential, institutional and commercial buildings and on personal property contents within those structures. The IICRC provides training and qualification by exam in Applied Microbial Remediation Technician certification.

Indoor Environmental Professional

An IEP is someone who has the relevant training, such as IICRC AMRT qualifications and experience to correctly scope a mould remediation project by performing a
moisture and mould assessment, to identify all potential risks and documenting them in project specific RAMS (Risk Assessment and Method Statement) before the commencement of the project. A strict mould remediation protocol must be followed to prevent cross-contamination
and to protect the health of workers and occupants. Mould remediation is highly technical and requires a scientific understanding of the effects of moisture on structural materials and the principles of air quality in the indoor environment and should only be performed by an IEP, such as WHITE KNIGHT.

Intrusive Inspections

If the building inspection reveals no obvious mould growth, there may still be growth within the walls, behind built-in units, ventilation systems, void spaces or other hidden locations.

Where risk factors for possible hidden mould growth are present e.g. history of water damage or building envelope failure, surface staining, mouldy odours etc., an intrusive inspection is necessary to determine the full extent of contamination. Intrusive inspections may involve carefully removing areas of skirting board, wallpaper, sections of floor coverings, such as carpet or vinyl flooring, ceiling tiles, cutting holes into wall or ceiling cavities.

Surface Sampling

Where contamination is evident, it is seldom necessary to test the mould, however, where mould growth is suspected and not visible, or where the presence and types of mould must be confirmed for health or legal reasons, then bulk, surface, or air samples should be obtained for laboratory analysis.

Air Sampling

The collection and interpretation of fungal air samples should be performed by indoor environmental professionals experienced in fungal and indoor air quality investigations where hidden mould growth is suspected or
for clearance testing after mould remediation is
completed, to confirm that an acceptable condition has been met before the containment barriers are removed and re-instatement works commence.

Laboratory Support and Sample Submission

Prior to mould sampling, it is important to identify a microbiology laboratory with experience and demonstrated performance in the identification of environmental moulds, such as WHITE KNIGHT enviroforensics. The laboratory can provide advice and references towards the development of the sampling strategy, including test methods, equipment, media, sampling time, transportation and analysis and reporting period. The analytical staff should have training and experience in the identification of environmental mould and bacteria and the laboratory should follow current best practices for environmental microbiology. The person submitting the samples must complete a chain of custody form to accompany all samples. A unique identifier is assigned to each sample and clearly marked on the sample packaging. The laboratory’s own COC form should be used and all applicable fields must be completed, including sample number, type of analysis requested, date of collection and the date by which results are required. The form should be signed and dated every time the sample changes hands. The analysis of bio-contaminants other than moulds such as E. Coli and salmonella requires specialised analysis that may be available from only a few laboratories.

Regulatory Compliance

Communicating the potential hazards of fungal remediation is a requirement of Environmental, and Health and Safety Legislation. Effective remediation and verification of cleanliness through scientific laboratory analysis are necessary to protect the health of the occupants. The primary response to fungal contamination in buildings must be the prompt remediation of contaminated material and infrastructure repair. Only qualified professionals should undertake these works following stringent protocols and methods that properly and safely remove fungal growth from buildings and contents, without cross-contaminating unaffected areas
or in any manner performing works that could adversely affect the health of the workers or occupants.

Insurance Considerations

The scientific and public health communities agree that indoor mould contamination poses a significant health risk and therefore visible mould should be removed immediately following an EOW or flood. If the water source is contaminated with sewage (CAT 3 Black Water), or contains chemical or biological pollutants, then a qualified IEP or IAQ (Indoor Air Quality) consultant should be engaged to perform an environmental survey on the fabric
of the property and to identify the associated risk factors from mould spore distribution, mycotoxins, hyphal fragments, MVOC’s (Microbial Volatile Organic Compounds) and other metabolites that are released into the air and inhaled or physically contracted via dermal exposure. Failure to act promptly can have a negative effect on scheduling, occupancy and overall claim costs.


The objective of mould remediation is to restore the indoor environment to its pre-loss condition and a ‘normal’ healthy fungal ecology. The presence of settled dusts containing spores from outdoor sources is considered normal, while the colonisation by any mould and the predominance of species that do not normally occur indoors are indicators of microbiological contamination. In all situations, the underlying cause of water ingress must be rectified or the fungal growth will recur. General contractors and associated trades should not attempt to remove mouldy materials without the proper training and engineering controls established or they could be in breach of HSE regulations, for the release of bio-hazardous agents in an indoor environment or face legal action from anyone affected by their erroneous actions.


Other News