Staff Health and Wellbeing Hub

Asthma in the workplace

Advice on asthma in the workplace

What is asthma?

Asthma is a health condition that affects the airways - the small tubes that carry air in and out of the lungs. There are around 4.3 million adults with asthma in the UK. In most cases, their asthma is not caused by work, but every year many people develop asthma because of the substances they are exposed to at work.

Occupational asthma

Occupational asthma is caused directly by work and is usually the result of a reaction that can occur in some people when they are exposed to certain substances known as respiratory sensitisers. Occupational asthma can be a serious condition leading to severe long-term asthma if exposure to respiratory sensitisers continues. The condition can take weeks, months or years to develop depending on the individual and the substance.

Work-related asthma

Work-related asthma is broader and includes substances in the workplace that irritate the airways of individuals with pre-existing asthma. Respiratory irritants may trigger attacks in those with occupational asthma or pre-existing asthma. Examples include chlorine, general dust and even cold air.


Symptoms of asthma include shortness of breath, wheezing, tightness in the chest and coughing. People can also develop other associated nasal conditions such as rhinitis, (sneezing, itchy, runny nose) or conjunctivitis (itchy, red, and inflamed eyes). The symptoms can develop right after exposure to a substance but sometimes they appear several hours later. The symptoms of occupational or work-related asthma can improve during weekends or holidays when a person has been away from work.

Causes of occupational asthma

There are many different substances that may cause occupational asthma. Below is a list of the most common respiratory sensitisers:

  • chemicals called isocyanates are the most common cause of occupational asthma in the UK
  • dust from flour and grain
  • wood dust
  • colophony (also known as rosin) – used in soldering, adhesives
  • dust from latex rubber
  • dust from insects and animals

Further information about the main causes of occupational asthma can be found in Section C of HSE's Asthmagen Compendium.

How to prevent occupational asthma?

You can prevent occupational asthma by avoiding exposure to respiratory sensitisers. This can be achieved by following these steps:

  • Respiratory sensitisers in your workplace should be removed or replaced with a safe alternative.
  • If this is not possible, exposure can be minimised through engineering controls such as enclosures and local exhaust ventilation.
  • If after carrying out the above steps you still have not achieved adequate control you will also need to use respiratory protective equipment (RPE) and commence health surveillance to ensure efficiency of control measures.

Health Surveillance

The Occupational Health Unit (OHU) provides lung function testing as part of a range of statutorily required Health Surveillance checks. If your COSHH risk assessment indicates that you may be exposed to respiratory sensitisers your manager should present your name to the OHU prior to commencement of the work to establish a baseline reading of your lung function and any ongoing requirement for lung function surveillance.

Further information on Health Surveillance is available on the Occupational Health Unit website.

Facefit testing

If you need to wear a well fitted face mask it is essential that you undertake a facefit test before commencing work. The Occupational Hygiene Unit runs the in-house facefit testing programme. Individual tests take approximately 30 minutes including respirator fit training. The test requires some simple exercises (head movements and talking aloud whilst walking on the spot) to be undertaken whilst wearing the respirator.

More information about the facefit testing can be found by following the link below:

Sources of Guidance and Advice

This information is sourced from Asthma UK and the Health and Safety Executive websites. For further information about asthma please see the links below.