Some people develop asthma because of where they work. This is known as occupational asthma. Around one in ten cases of adult onset asthma are related to the workplace.
Occupational asthma is caused by substances breathed in at work, such as dust, chemicals, fumes and animal fur.
You may have been at your place of work for weeks, months or even years before you start having asthma 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.
Unlike pre-existing asthma, the symptoms of occupational asthma can go away completely if they’re identified soon enough, and you stop being exposed to the trigger.
For some people, their symptoms stop as soon as they’re no longer in contact with the trigger; for others it can take a bit longer.
Sometimes symptoms don’t go away completely or can go on for years. This is usually because your occupational asthma wasn’t spotted soon enough, or your symptoms were more severe.
Even if your symptoms do go away though, the substance that set them off will always be a trigger for you, so you’ll need to avoid it, which means avoiding similar workplaces.
You’re most at risk if:
- You have a history of allergies. This makes it more likely that you’ll develop an allergy to the substances at work known to trigger asthma.
- You have rhinitis. Occupational rhinitis is an early warning sign that you may develop occupational asthma.
- You smoke. Studies suggest that smoking increases your risk of being sensitive to certain occupational triggers.
- Your workplace has high levels of occupational asthma allergens or irritants.
You’re more at risk of developing occupational asthma in workplaces where there are higher levels of allergens or irritants.
Workplaces with high rates of occupational allergens include:
- Bakeries, flour mills and kitchens where flour dust and additives in the flour are the second most common cause of occupational asthma.
- Hospitals and other healthcare settings can have triggers like natural rubber latex proteins found in latex gloves, as well as particles and vapours from surgical techniques.
- Pet shops, zoos, and animal laboratories expose you to allergens like pet fur, dander, and saliva, and dusts from animal enclosures.
- Farms and agricultural workplaces produce a range of agricultural dusts such as grain dust, poultry dust, or other dusts that are a mix of materials from fungal spores, bacteria, endotoxins, mites, animal dander and faeces. Dusts are the most common cause of occupational asthma among agricultural workers.
Workplaces with high rates of occupational irritants include:
- Car manufacture and repair workshops expose workers spraying cars and other vehicles to a chemical called isocyanate (typically in 2-pack paints). Isocyanate is the most common cause of occupational asthma.
- Woodwork and carpentry workshops produce dusts from hardwood, softwood and wood composite when it is machined or sanded.
- Electronics and assembly industries expose people to irritants from fumes from rosin-based solder flux.
- Engineering and metalwork workplaces – people who work in machining or shaping are exposed to metal working fluids (MWFs) which can cause occupational asthma if you inhale the mist or vapour.
- Hairdressing salons can expose workers to chemical irritants such as hairdressers’ bleach containing persulphate, and henna.
- Indoor swimming pools expose workers like lifeguards or swimming teachers to airborne chloramines. This is when the chlorine in the water reacts with bodily proteins creating an airborne irritant in the air around the pool.
The most important thing you can do if you suspect occupational asthma is act quickly.
The symptoms of occupational asthma can go away if you’re removed from the substance triggering it early on. But the longer you leave it, the more likely it is that you’ll develop long term asthma, even if you do remove yourself from the triggers, or even if you leave your job.
- Tell your employer straightaway if you notice any early warning signs like nose or eye irritation or rhinitis. And talk to your employer about other job roles that mean you have less contact with the substance causing you problems.
- Make an appointment with your GP or asthma nurse as soon as possible to confirm the diagnosis, and to get the advice and support you need to manage your asthma symptoms.
Make an appointment to see your GP so you can talk about your job and the substances you’re exposed to at work. Tell them about any symptoms you’ve noticed, like sneezing, runny nose, or conjunctivitis (itchy, red, inflamed eyes), or shortness of breath, cough, chest tightness or wheeze.
To help confirm or rule out a diagnosis of occupational asthma, your GP will want to know if:
- your asthma symptoms started as an adult, or your childhood asthma symptoms have returned since you started working
- your symptoms improve on the days you’re not at work or on holiday
- your symptoms get worse after work or disturb your sleep after work.
If your GP suspects occupational asthma they may:
- refer you to a specialist in occupational medicine
- offer blood tests or skin prick tests to confirm any allergies. (If your symptoms are triggered by irritants, rather than allergens, this won’t show up in an allergy test.)
- ask you to keep a peak flow diary, so they can look at your peak flow scores both at work, and at home
- offer you a ‘challenge test’ if it’s been difficult to find out exactly which substance at work is triggering your asthma. This is where you’re asked to breathe in substances thought to be causing your symptoms to see if any trigger your asthma symptoms. It's quite a difficult test so it will only be done in specialist centres where you can be closely monitored.
- Prescribe a preventer inhaler to deal with underlying inflammation; and a reliever inhaler so you can control symptoms when they come on.
It’s understandable to be worried about losing your job, or income if your job role changes, due to a diagnosis of occupational asthma.
Some people who develop occupational asthma need a change of job role where they work, or even to change jobs altogether, which is not always an easy solution.
But try not to let financial or employment fears hold you back from getting help with your symptoms, and a diagnosis. Remember that if you act quickly there’s more chance of your symptoms going away. If you ignore your symptoms you’re putting yourself at risk of an asthma attack, and of having asthma long term.
What your employer needs to do
Your employer has a duty under the Health Safety at Work Act 1974. This means they must minimize any exposure to hazardous substances in the workplace.
If your work involves you having contact with allergens or irritants, this should have been explained to you before you started work.
You should also have completed a brief health screen check, including a breathing test at the start of your employment. This is something you need to do again, every year, to make sure you’re not developing asthma.
If you do develop occupational asthma your employer should notify the Health and Safety Executive (HSE).
How your employer can help
Your employer can see if changes can be made to your current job to make it safer for you.
For example, they could:
- remove or replace any products or substances triggering your asthma with a safe alternative
- reduce the risk for you by isolating you from substances that trigger your symptoms
- provide you with respiratory protective equipment (RPE) such as a mask, so you can avoid inhaling the irritating substances or vapours.
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
- contact your trade union or professional body
- tell your manager about your concerns
- contact the local HSE office (or the local council environmental health department) for advice.
Can I get compensation if I'm diagnosed with occupational asthma?
It may be possible to get compensation. 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.
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.
If you want to take legal action, you normally have three years from the time you know that you have asthma caused by work to start the action.
The sooner court proceedings can be started, the better it’s likely to be for you. You should consult a lawyer who has experience in occupational diseases.
If you’re a member of a union then 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.
Need more support?
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 for each of these industries.
If you’ve already got asthma (not occupational asthma) and you’ve noticed your symptoms getting worse when you’re at work, you can get more advice here.
And don’t forget you can speak to one of our asthma nurse specialists on 0300 222 5800 (9am-5pm; Mon-Fri) or WhatsApp them on 07378 606 728.
Last reviewed January 2019
Next review due January 2022