Construction hazardous substances: Harmful micro-organisms

Construction workers can be exposed to a range of harmful micro-organisms such as bacteria ,viruses and fungi. These pages tell you how to control these risks and why.

What you must do

The Control of Substances Hazardous to Health (COSHH) Regulations says you must protect against the risks from hazardous solvents. Follow the Assess, Control and Review model. Pay particular attention to:


Identify and assess: Construction workers can be exposed to a variety of micro-organisms. The level of risk depends on the type of micro-organism and the work being done. Identify those situations where significant micro-organism risks are likely to be present. Pay particular attention to specific tasks during groundwork, demolition or refurbishment.


Prevent: Think about limiting the risks before work starts.

Control: Follow the general controls below where a risk remains. You may need additional controls for specific tasks.

  • Clothing – use disposable coveralls, gloves etc where appropriate. This clothing should be kept separate from personal clothing worn outside of work hours. Non-disposable overalls should be replaced when soiled and washed with detergent at a high temperature before being re-used.
  • Washing – washing is an important control. In many cases standard site welfare facilities will be enough – see the controls for specific tasks where this is not the case. Workers should also:
    • wash hands and forearms before eating, drinking, smoking, using the telephone, taking medication, inserting contact lenses etc
    • avoid hand-mouth or hand-eye contact when in contaminated areas
    • dispose of all contaminated waste safely
  • Breaks – avoid contamination by taking rest and meal breaks away from the work area.
  • First aid – make sure first aid equipment is fully stocked / maintained and readily available. Cover existing cuts and grazes. Wash any new cuts or grazes immediately with soap and running water and apply a waterproof dressing;
  • Vaccination – there is effective immunisation for some diseases like Hepatitis A, Hepatitis B and Tetanus.  A decision to vaccinate will depend on a number of factors. A case-by-case approach should be taken in conjunction with an occupational health provider or advice from a General Practitioner. Consider relevant factors including the length of time the work will take, how regularly it is done, the amount of contamination present or if similar work has caused exposure / illness in the past.

Train: Workers need to be aware of the micro-organisms they may be exposed to and how to use the controls properly. They should also be made aware of the relevant signs / symptoms associated with any of these micro-organisms and how to report these to managers / their General Practitioner.


Supervise: Ensure that controls such as work methods, PPE and welfare are appropriate, effective and used by the workers.

Monitor: Health Surveillance will not normally be required. Any vaccinations should be discussed in conjunction with an occupational health provider / General Practitioner where appropriate.

What you should know

Construction workers may be at greater risk from micro-organisms when doing some specific tasks or working on particular sites. Information on these risks and how to control them can be found below:

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Updated 2021-10-07