Asthma is a very serious health problem that can ruin lives.

Breathing in certain dusts, gases, fumes and vapours within the workplace can cause asthma. 

Shortness of breath, wheezing and painful coughing are just some of the symptoms that occupational asthma sufferers may have to deal with every day.

Advice for employers 

There are many things you can do as an employer to reduce the risk of occupational asthma in your workplace.  

The Your trade page of the Health and Safety Executive (GB) website provides top tips for a healthy workforce:

You can find useful guidance and information on the Asthma publications page of the HSE (GB) website:

Advice for employees

Asthma is a very serious health problem and is a condition that affects the airways – the small tubes that carry air in and out of the lungs. It is a complicated, chronic and often frustrating disease.

What is asthma?

Asthma is a chronic inflammation of the bronchial tubes (airways) that causes swelling and narrowing (constriction) of the airways. The result is difficulty breathing. The bronchial narrowing is usually either totally or at least partially reversible with treatments.

When a person with asthma comes into contact with something that irritates their airways (an asthma trigger), the muscles around the walls of the airways tighten so that the air ways become narrower and the lining of the airways becomes inflamed and starts to swell.  

Sometimes sticky mucus or phlegm builds up which can further narrow the airways.  

All these reactions cause the airways to become narrower and irritated - making it difficult to breath and leading to symptoms of asthma:

  • 5.4million people in the UK are currently receiving treatment for asthma
  • 1.1million children in the UK are currently receiving treatment for asthma
  • there is a person with asthma in one in five households in the UK

Occupational asthma

Occupational asthma is an allergic reaction that can occur in some people when they are exposed to substances, for example flour or wood dust in the workplace.

These substances are called 'respiratory sensitisers' or asthmagens. They can cause a change in people’s airways, known as the 'hypersensitive state'.

Not everyone who becomes sensitised goes on to get asthma. But once the lungs become hypersensitive, further exposure to the substance, even at quite low levels, may trigger an attack.

Work-related asthma

Work-related asthma or asthma made worse by work is broader and includes substances in the workplace that irritate the airways of individuals with pre-existing asthma. This includes people who have had asthma since childhood.

Respiratory irritants may trigger attacks in those with occupational asthma or pre-existing asthma.

Examples include:

  • chlorine
  • general dust
  • cold air

Causes of asthma

It is difficult to say for sure what causes asthma.  What we do know is that:

  • you are more likely to develop asthma if you have a family history of asthma, eczema or allergies
  • it is likely that this family history combined with certain environmental factors influences whether or not someone develops asthma
  • many aspects of modern lifestyles – such as changes in housing and diet and a more hygienic environment – may have contributed to the rise in asthma over the last few decades
  • research has shown that smoking during pregnancy significantly increases the risk of a child developing asthma
  • children whose parents smoke are more likely to develop asthma
  • environmental pollution can make asthma symptoms worse and may play a part in causing some asthma
  • adult onset asthma may develop after a viral infection
  • irritants found in the workplace may lead to a person developing asthma (occupational asthma)

Symptoms of asthma

Asthma is a serious health problem. Thousands of people have to face the challenges of this disease every day.

Symptoms include severe shortness of breath that can stop you from doing the simplest tasks. Imagine not being able to carry your shopping or walk up the stairs or even play with your children. Some sufferers are unable to work again.

Other symptoms include:

  • wheezing
  • coughing
  • chest tightness

The symptoms can develop right after exposure to a workplace substance. But sometimes symptoms appear several hours later, possibly at night. This can make any link with workplace activities unclear. Other associated conditions are:

  • rhinitis (sneezing/runny nose)
  • conjunctivitis (itchy and inflamed red eyes)

Treatment of asthma

Although there is no cure for asthma, there are some excellent medicines available to help you to control your asthma so that it does not interfere with your daily life.

It is important that you take your asthma medicine properly and that your doctor or asthma nurse has explained how to use inhaler’s properly so that every dose you take gives you the most benefit.

  • your doctor or nurse will also tailor your asthma treatment to your symptoms
  • you should be offered
  • care at your GP surgery provided by doctors and nurses trained in asthma management
  • full information about your condition and how to control it
  • involvement in making decisions about your treatment
  • regular checks to ensure that your asthma is under good control and your treatment is right for you(which should be at least once a year)
  • a written personal asthma action plan agreed with your doctor or nurse

Controlling your asthma

If your asthma is under control you are more likely to have a better quality of life and be able to do the things you want to.

Is your asthma under control?

The following three questions can help you to identify whether your symptoms are under control. In the last month:

  • have you had difficulty sleeping because of your asthma symptoms (including cough)?
  • have you had your usual asthma symptoms during the day (cough, wheeze, chest tightness or breathlessness)?
  • has your asthma interfered with your usual activities – for example, housework, work, school

If you have answered yes to any of the above questions it may be that your asthma is not controlled as well as it could be.  

See your doctor or asthma nurse to discuss ways that you may be able to improve your asthma control.

Signs that your asthma is not well controlled

Signs may include:

  • waking at night with coughing, wheezing, shortness of breath or a tightness in the chest
  • having to take time off work because of your asthma
  • finding it difficult to breathe, and breathing short shallow breaths
  • needing more and more reliever treatment
  • finding that your reliever does not seem to be working
  • having to take your reliever more frequently than every four hours
  • feeling that you cannot keep up with your usual level of activity or exercise

If you notice any of these symptoms you should follow your personal asthma action plan, as this should help you to get your symptoms back under control.  If this does not work, you should see your doctor or asthma nurse. This may involve looking at your medicines, triggers and lifestyle to see if anything can be changed.

Asthma at work

Every year in the UK, up to 3,000 develop asthma because they are exposed to dangerous substances at work.  This is called occupational asthma.

750,000 people with asthma find that things at work make their asthma worse.

What is occupational asthma?

Some substances that you might come across at work can actually cause asthma.  

The condition can take weeks, months or even years to develop, depending on the person and substance.

If you think your asthma has been caused by something at work, look out for these clues:

  • your asthma symptoms are worse during the working week, at work or after work
  • your symptoms may get worse after work, or you may find your sleep is disturbed during the night
  • your symptoms improve when you have been away from work for several days (e.g. when you are on holiday)

Which substances can cause occupational asthma?

Substances that can cause asthma are called respiratory sensitizers or asthmagens. Below is a list of the main ones and the jobs where you are most likely to come across them:

  • Chemicals called isocyanates are the most common cause of occupational asthma in the UK -  there are many jobs in which you might be exposed to these chemicals, particularly spray painting, foam moulding using adhesives, and making foundry cores and surface coatings.
  • dust from flour and grain, industrial baking, farm work and grain transport.
  • wood dust, particularly from hard wood dusts and western red cedar if working in carpentry, joinery or sawmilling.
  • colophony – this is widely present in soldering fumes but also in glues and some floor cleaners.
  • electronics industry.
  • dust from latex rubber - any job involving latex gloves, such as nursing or dentistry.
  • dust from insects and animals, and from products containing them.
  • laboratory work.
  • farm work or work with shellfish.

How to prevent occupational asthma

You can prevent occupational asthma by avoiding exposure to respiratory sensitizers.  To achieve this you should follow these steps:

  • Try to get any respiratory sensitizers in your workplace removed or replaced with a safe alternative.
  • If this isn’t possible, your employer can reduce the risk by installing extractor fans or isolating you from the process that produces the risk by putting dangerous chemicals in a fume cupboard, for example - these steps can reduce the respiratory sensitizers you breathe in.
  • If the above steps aren’t possible, you should wear breathing equipment to stop you inhaling the respiratory sensitizer.

Often a combination of all these steps will be needed. The main causes of occupational asthma are set out in Section C of HSE's Asthmagen Compendium:

What your employer can do to help

Your employer has a legal duty to deal with respiratory sensitizers in the workplace.  This is set out in the Control of Substances Hazardous to Health Regulations (Northern Ireland) 2003 (COSHH).  

Your employer should carry out a risk assessment and inform you if any respiratory sensitizers are present.  You should also be told how to recognise early signs of occupational asthma.

If you are working with respiratory sensitizers, it is often necessary to have regular medical checks so the condition can be spotted early.

Your employer should consult you (either directly or through your union or employee representative) about the need to control respiratory sensitizer’s and triggers and the steps they plan to take to do this.

Most employers will do what they can to help.  If you don’t think that they are doing enough you can:

  • raise the issue with the person responsible for health and safety in your workplace
  • tell your manager about your concerns
  • contact the local HSENI office (or the local council environmental health department) for advice on what to do next

Your colleagues also have a legal duty not to do things that endanger your health (such as smoking near you). Remember that having a legal right doesn’t always mean you can enforce it.  Be tactful and choose the right moment to raise the issue.

What if I think I have occupational asthma

First of all, see your doctor straight away.  If they suspect that you do have occupational asthma, they should refer you to a specialist.  If occupational asthma is confirmed, your doctor should, with your consent, advise your employer to relocate you away from the respiratory sensitizer.

Diagnosis of occupational asthma does not always mean you have to leave your job.  Talk to your employer and health and safety representative about other options available to you.  However, if you feel leaving work is the only option; you should make a claim for compensation.

How is occupational asthma diagnosed?

Occupational asthma may be diagnosed:

  • if your asthma is worse during the working week, though not necessarily at work itself or your symptoms get worse after work, or you find your sleep is disturbed during the night.
  • your symptoms may improve when you have been away from work for several days or on holiday.
  • if occupational asthma is suspected, you should be referred to a specialist.

Can I get compensation if I develop occupational asthma?

If you develop asthma because of your work you should:

  • tell your GP that you think the asthma was caused by your work
  • tell your manager or safety officer and ask to record it in the workplace accident book
  • tell your union representative - if you belong to a union they may be able to get you compensation if your employer is at fault
  • make a claim for Industrial Injuries Disablement Benefit 
  • Industrial Injuries Disablement Benefit - nidirect website


Key legislation

Please note that these links are to the original legislation, visitors should verify for themselves whether legislation is in force or whether it has been amended or repealed by subsequent legislation.