This page is mainly for employers of people who could be exposed incidentally to biological hazards during their work activity or in their working environment.
What incidental exposure means
Incidental exposure to biological agents can occur when a worker’s activity brings them into contact with material which contains infectious agents, for example:
- blood or body fluids
- contaminated water
- waste material or bedding/laundry
- legionella from buildings
Some occupations have a relatively high likelihood of occupational exposure, for example healthcare and farming.
There is separate guidance on:
- how you should be protected from infection as a worker
- deliberate work with biological agents, for example in laboratories
How to identify, assess and control incidental exposure
If there are biological agent hazards at your workplace, in line with your duties under the Control of Substances Hazardous to Health (COSHH) , you should manage the potential health and safety risks in any workplace by carrying out a risk assessment.
There is HSE guidance that will help you assess the risks:
The following steps can help you assess and control incidental exposure to biological agents.
Identify incidental exposure risk and biological agent hazards
Not all micro-organisms can cause infections and disease. Employers must assess whether their activities could put their staff at risk of exposure to harmful biological agents.
There are various work activities and work environments likely to involve biological agents.
Examples of materials that are likely to contain biological agents are bodily fluids, sewage, clinical waste, metalworking fluids, animals and animal fluids.
If you do not identify any specific biological hazards in your workplace, hygiene arrangements should be in place, as described in our guidance about the law on workplace health, safety and welfare.
Assess who may be harmed and how
You must identify who might may be exposed to hazardous biological agents at your workplace. This should include any vulnerable workers, contractors, visitors or members of the public.
Your assessment needs to consider:
- how exposure can take place during work activities
- the level, type and duration of exposure, and contamination of surfaces or equipment
- the ability of the biological agents to survive for long time periods
Control biological hazards
Before identifying control measures, consider whether you can remove the biological hazard from your workplace. In some workplaces, such as healthcare or farming environments, this may not be possible, so you should identify how to control exposure.
Consider whether engineering controls could be used to prevent exposure, for example local exhaust ventilation. Consider how to prevent exposure by changing your work processes to reduce the:
- likelihood of exposure
- number of workers being exposed
- spread of infectious material
Consider using safer equipment and/or procedures to reduce the likelihood of exposure, use of disinfectants to reduce the levels of biological agent contamination, availability of surfaces that can be easily cleaned, and hygiene arrangements.
You should also consider the use of PPE, such as gloves or overalls, in line with the COSHH guidance hierarchy of control measures. There is more guidance on:
- using PPE to control risks at work
- choosing the right gloves to protect skin
- respiratory protective equipment (RPE)
Identifying control measures does not need to be carried out in isolation. In many workplaces, procedures are designed to control exposure to biological hazards. Consider industry standards and guidance that may apply to you.
Depending on your activities, you may need to put systems in place to deal with any emergencies, such as:
- emergency procedures
- handling of contaminated waste
- the use of PPE, such as how to use, store, dispose of or clean it when appropriate
If the risk assessment concludes there is a risk of exposure to biological agents for which effective vaccines are readily available, you should offer them. The HSW Act requires employers to provide protective measures such as immunisation to workers free of charge.
If available, a pre-exposure screening programme and appropriate follow-up assessments should show if employees are immune to the relevant agent. It is recommended that employers keep a record of the screening outcomes and employees’ vaccinations. The records should include when any boosters or any follow-up screenings are due.
The advantages and disadvantages of immunisation, as opposed to non-immunisation, should be explained when making the offer. Immunisation should be seen only as a useful supplement to reinforce physical and procedural control measures, not as the sole protective measure.
Employees may not wish to take up the offer of immunisation, or they may not respond to a vaccine and will, therefore, not be immune. If so, as an employer, you should consider the effectiveness of the other controls and consider whether any additional controls should be implemented to allow them to work safely.
You may find it helpful to refer to guidance on immunisation against infectious disease (on GOV.UK) or contact an occupational health provider for advice.
Specific industry and workplace guidance
To help you identify specific biological hazards due to the work environments, activities and materials handled, the following section provides specific industry/workplace guidance or links to information.
Health and social care
Health and social care covers a large group of workers such as clinical and support staff at hospitals, nursing homes, GPs, dental practices and other locations.
The nature of work at healthcare and clinical related environments means biological hazards are going to be encountered, for example bloodborne viruses and diarrheal or respiratory agents.
Due to the clinical nature of activities within healthcare workplaces and requirements for infection control, measures in place to control exposure to biological agents are likely to be embedded in work procedures. There are established clinical standards and guidance on infection control:
- NHS England: National Infection Prevention and Control Manual - Standard infection control precautions
- NHS Scotland: National Infection Prevention and Control Manual Chapter 1 - Standard infection control precautions
There is more information on specific groups of biological agents relevant to healthcare environments:
Farming (avian flu), veterinary and animal-related workplaces
Biological hazards are likely to be present in various farming, agriculture, veterinary and animal-related workplaces which could cause a zoonotic infection.
Farm-related guidance is available:
- preventing or controlling ill health from animal contact at visitor attractions or open farms
- Code of Practice on Access To Farms (on the Visit My Farm website)
Avian influenza
Avian influenza hazards in poultry, farmed-bird-related environments and occupations involving wild birds or other wildlife could affect workers. It mainly affects birds and is sometimes referred to as bird flu, caused by influenza A viruses which are not well adapted to infect humans. Human infections with avian influenza viruses in the UK are rare.
Some subtypes, such as A(H5N1) or A(H7N9), have been associated with human disease, usually in people directly exposed to infected birds or animals, or contact with faeces from an infected bird or an infected bird that has died. You can find further information on human avian influenza infections:
- Bird flu – NHS
- NHS 111 Wales: Avian flu (bird flu)
- What is bird flu and how are we protecting people against it in the UK? – UK Health Security Agency
All birds are susceptible to avian influenza A and the virus can rapidly cause significant mortality in farmed bird environments such as poultry farms. There is further information on avian influenza and how it affects birds and wildlife:
- Bird flu (avian influenza): how to spot and report it in poultry or other captive birds (on GOV.UK)
- Bird flu (avian influenza): latest situation in England (on GOV.UK)
- Guidance for the management of people exposed to birds or other animals infected with influenza A(H5) (on GOV.UK)
Some occupations or workplaces may involve the handling of farmed birds, wild birds, other wildlife animals susceptible to bird flu, such as seals.
Examples of these work areas include poultry houses, zoos, bird sanctuaries, pigeon lofts, pet shops, quarantine areas and abattoirs. In these environments it is important to carry out risk assessments and use the right equipment and good hygiene methods to protect workers as described in HSE’s guidance on avian influenza.
HSE also has practical guidance for people working with birds: Avoiding the risk of infection when working with poultry that is suspected of having H5 or H7 notifiable avian influenza.
Brucella canis
This zoonotic pathogen affects animals, mainly dogs, and it can be transmitted to humans. During recent years, there has been an increase of positive cases detected in imported dogs from Eastern Europe.
Veterinary staff such as surgeons could be at risk of exposure to this zoonotic agent if appropriate controls are not taken. There is more information on assessing risks and control measures at veterinary practices in Brucella canis: risks and control measures in veterinary practices (on GOV.UK)
Bovine spongiform encephalopathy (BSE)
BSE is a fatal, degenerative disease of the central nervous system that occurs in cattle. It is one of a number of similar diseases known as transmissible spongiform encephalopathies (TSEs) which occur in human and various animals. The most common form of human TSE is known as Creutzfeldt-Jakob disease (CJD).
Variant CJD (vCJD) is likely to be caused by consuming meat from a cow that had bovine spongiform encephalopathy (BSE or ‘mad cow’ disease), a similar prion disease to CJD. Because BSE and vCJD are caused by the same agent, there may be a risk to those in occupations where exposure to BSE may occur. These include abattoir/slaughterhouse workers, farmers, veterinary surgeons, butchers and incinerator or landfill operators.
You can find more information on how to assess BSE risks at relevant workplaces in BSE - Occupational guidance (WEB22).
Construction and metalworking industries
Depending on the nature, location and extent of the construction activity, exposure to biological hazards should be considered. You can find guidance on construction hazardous substances: harmful micro-organisms.
Fluid systems that contain water or water-mixes can become highly contaminated with harmful bacteria that workers could be exposed to. HSE has more information on bacterial contamination.
Water-using/storing or aerosol producing workplaces (legionella)
Extensive information on identifying and controlling legionella hazards from water sources is available in HSE’s guidance on legionella and Legionnaires' disease.
Sewerage sector
Biological agents are an inherent part of sewage, the hazard cannot be eliminated so an assessment of risks should be made.
You can find guidance on the health hazards of working with sewage.
Food industry
Some food industry workplaces, such as poultry-processing environments, could present a biological hazards due to micro-organisms that could be present, for example Campylobacter or Salmonella bacteria. HSE’s website has more information on ill-health risks in working with meat, poultry and fish.
Some food industry sectors may need to consider bovine spongiform encephalopathy (BSE) hazards which are also relevant to farming environments. There is Food Standards Agency advice on BSE.
Waste and recycling services
You can find information on biological hazards in waste and recycling work environments in preventing ill health in waste and recycling. It includes guidance on:
- infectious material found in waste
- routes to infection
- preventive and protective measures
There is also information on biological agents and anaerobic digestors in our guidance on disposal and energy recovery.
The care, transport or preparation of the deceased
Workers in a range of different occupations are required to handle the deceased at various stages of the pathway from death to burial or cremation.
They may therefore be exposed to a risk of infection, including during preparation of the deceased by funeral service staff, at post-mortem examination and, in restricted circumstances, during exhumation.
There is more information on managing infection risks when handling the deceased.
Mail handling (malicious exposure to biological agents)
Workplaces are likely to be receiving post such as letters and deliveries of small packages. These are potential routes into premises for terrorists.
Delivered items may be explosive, incendiary, contain sharps or blades, or chemical, biological or radiological material. There is guidance on mail handling from ProtectUK that explains:
- assessing the risks an organisation faces from postal threats
- implementing appropriate screening and security measures (either internally or outsourced)