Occupational asthma

Find out more about occupational asthma, how it is diagnosed and treated, what allergens and irritants cause it, and where you can get support if you’re worried about losing your job.

Occupational asthma is caused by breathing in substances at work, like dust, chemicals, fumes and animal fur.

If you develop new asthma symptoms at work, or your childhood asthma comes back, you could have occupational asthma.

You may be at your workplace for a while before you notice symptoms. This is because it takes a while for your immune system to become sensitive to workplace triggers.

But once you’ve become sensitive to a substance at work, it can trigger asthma symptoms the next time you come in contact with it – even if it’s just in small amounts.

Symptoms to look out for are:

• Cough
• Wheeze
• Tight chest
• Shortness of breath
• Conjunctivitis (itchy, red, inflamed eyes)
• Rhinitis (where the inside of your nose is inflamed with symptoms like a blocked, runny or itchy nose).

As soon as you notice symptoms, see your GP.

Occupational asthma is confirmed or ruled out after a consultation with your GP. You will discuss your symptoms, when you get them, your work, and medical history. You may also need some tests.

Questions your GP may ask you

Before you go, think about your answers to these questions. It will help you and your GP work out if you have occupational asthma or not.

• Did your asthma symptoms start as an adult?
• Have your childhood asthma symptoms come back since you started working?
• Do your symptoms get better on days you’re not at work or when you’re on holiday?
• Do your symptoms get worse after work or disturb your sleep after a work day?
• Do you have a history of allergies which could increase your risk of allergies at work?
• Do you smoke, which increases your risk of being sensitive to work triggers?
• Do you have rhinitis? Occupational rhinitis is an early warning sign for occupational asthma.

Tests to help confirm a diagnosis 

If your GP thinks occupational asthma is a possibility, they may suggest tests to confirm a diagnosis.

Peak flow 

Your GP may ask you to use a peak flow meter, and keep a peak flow diary, so they can look at your peak flow scores - both at work and at home. For this to be useful, you’ll need to do four readings a day, for about three weeks.

Blood tests or skin prick tests 

These are to confirm any allergies. If your symptoms are triggered by irritants, rather than allergens, this won’t show up in an allergy test.

Challenge test 

This is where you breathe in substances thought to be causing your symptoms, to see if any trigger your asthma symptoms. This is quite a difficult test, so it will only be done in specialist centres where you can be closely monitored.

If things are still not clear, or hard to prove exactly which substance at work is triggering your asthma, your GP may refer you to a specialist in occupational asthma.

The good news is that if you catch it soon enough, the symptoms of occupational asthma can sometimes go away completely, as long as:

• it’s diagnosed quickly
• the cause is identified
• you stop being exposed to the trigger

For some people, symptoms stop straight away. For others, it can take a bit longer.

Even if your symptoms do go away, the substance that set them off will always be a trigger for you, so you’ll need to avoid it. This may mean avoiding similar workplaces.

If symptoms continue

Sometimes symptoms don’t go away completely or can go on for years, even after you’ve stopped being exposed to the trigger.

This is usually because your occupational asthma wasn’t spotted soon enough, or your symptoms were more severe.

See your GP or asthma nurse as soon as possible to get the advice and support you need to manage your asthma symptoms and lower your risk of symptoms and an asthma attack.

They may prescribe a preventer inhaler to deal with underlying inflammation and a reliever inhaler to control symptoms when they come on.

Find out more about managing your asthma well and inhalers and treatments for asthma.

Workers at higher risk of developing occupational asthma include cooks, hairdressers, mechanics and healthcare workers.

Occupational asthma is more of a risk where there are high levels of allergens or irritants at work, such as:

Occupational allergens

• Flour dust and additives
• Latex used in healthcare settings
• Animal fur, skin and saliva, as well as dust from animal enclosures
• Grain and poultry dusts - the most common cause of occupational asthma among agricultural workers
• Vapours and particles from surgical techniques in hospitals

Occupational irritants

• Chemicals used in car spray paints, or bleach used in hairdressing salons
• Wood dust produced when machining or sanding
• Fumes, mists and vapours from electronic, engineering or metal work, from adhesives, and from chlorine in indoor pools.

Some people who develop occupational asthma need a change of job role where they work, or even to change jobs altogether.

It’s understandable to be worried about losing your job, or income, if your job role changes due to a diagnosis of occupational asthma.

But try not to let financial or employment fears hold you back from getting help with your symptoms, and confirming a diagnosis.

Talk to your employer, or your occupational health doctor or nurse if you have one, as soon as you notice symptoms. If you have a union representative, they may be able to support you.

There may be things you can do to prevent you losing your job altogether. For example:

• moving you to a different role so you’re not exposed to problem triggers
• replacing any products or substances triggering your asthma with safe alternatives
• providing you with PPE (Personal Protective Equipment) such as masks, so you can avoid inhaling the irritating substances or vapours.

Under the Health Safety at Work Act 1974 employers must minimise any exposure to hazardous substances in the workplace.

If your work involves you having contact with allergens or irritants:

• risks should be explained to you before you start work
• you should have a health check, including a breathing test, when you start employment
• you should have health checks every year, to make sure you’re not developing asthma
• your employer should notifiy HSE (the Health and Safety Executive) if you develop occupational asthma

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

• talking to your health and safety rep at work
• contacting your trade union or professional body
• contacting the local HSE office (or the local council environmental health department) for advice.

If you’re told that your asthma has been caused by your job, you should get advice quickly both about compensation and about benefits you may be entitled to.

The level of benefit you get will depend on the severity of your disability. You may be eligible for Industrial Injuries Disablement Benefit or be eligible for Reduced Earnings Allowance.

It’s important to claim your benefit as soon as possible. Payments will only start from the day you claim, not the day you found out you had occupational asthma.

You normally have three years from the time your occupational asthma symptoms started to begin legal action.

The sooner court proceedings can be started, the better it’s likely to be for you. You should get expert advice from a lawyer with experience in occupational diseases.

If you’re a member of a union, they’ll help you find an experienced lawyer. If you’re not a member of a union, you can get free advice from your local Citizens Advice Bureau.

There are many other respiratory triggers at work, and more are being identified all the time.

The Health & Safety Executive (HSE) publishes a list of the best known substances, which is updated regularly. You can also get top tips on avoiding occupational asthma.

If you’ve already got asthma (not occupational asthma) but you’ve noticed your symptoms getting worse when you’re at work, you can get more advice here.