Occupational Asthma Claims
Occupational asthma is asthma caused or made significantly worse by exposure to substances at work. It is one of the most common industrial diseases in the UK, affecting bakers, paint sprayers, healthcare workers, woodworkers, and many others. When an employer fails to control exposure to a known asthma trigger and a worker develops asthma as a result, a compensation claim may follow.
In this guide
- What Is Occupational Asthma?
- Common Triggers of Occupational Asthma
- The Legal Test for an Occupational Asthma Claim
- What Compensation Could You Receive?
- Who Can You Claim Against?
- Government Schemes
- Time Limits
- Evidence That Strengthens an Occupational Asthma Claim
- Why Diagnosis Timing Matters
- No Win No Fee Occupational Asthma Claims
- Common Questions About Occupational Asthma Claims
- Related Guides
- Our Partner's Fees Explained
- Check If You Could Claim Compensation For Your Injury
This guide explains what counts as occupational asthma, the most common triggers, what compensation typically covers, and how to start a claim on a no win no fee basis.
What Is Occupational Asthma?
Occupational asthma is asthma where the trigger is a substance encountered at work. It comes in two forms:
- Sensitisation-induced occupational asthma — the worker develops a specific allergic-type response to a substance, leading to asthma whenever they are subsequently exposed. This is the most common form and accounts for about 90 per cent of cases. It can take months or years of exposure before symptoms appear
- Irritant-induced occupational asthma (RADS) — sudden onset of asthma after one or more high-level exposures to an irritant substance. Less common but well recognised
Occupational asthma is distinct from work-aggravated asthma, where pre-existing asthma is made worse by workplace conditions but the work did not cause the original asthma. Both can lead to compensation claims, but the legal analysis is different.
Common Triggers of Occupational Asthma
Hundreds of substances have been identified as causing occupational asthma. The most common in UK claims are:
- Isocyanates — used in paint spraying, foam manufacture, and adhesives. The single most common cause of occupational asthma in the UK
- Flour and grain dust — affecting bakers, millers, and grain handlers
- Wood dust — particularly hardwood dusts like oak, beech and western red cedar
- Latex — affecting healthcare workers, cleaners, and laboratory staff
- Animal proteins — affecting vets, lab workers, farmers and pet handlers
- Solder and colophony fumes — affecting electronics workers
- Cleaning products — bleach and chlorine in cleaners, hospitality and healthcare
- Hairdressing products — particularly persulphates in bleaches
- Welding fumes — affecting metalworkers, fabricators, and shipyard workers
- Glutaraldehyde and other healthcare disinfectants — affecting endoscopy nurses and lab workers
- Enzymes — in food manufacturing and detergent production
- Acid anhydrides and amines — in chemical and plastics manufacturing
A complete list is maintained by the Health and Safety Executive. If you have developed asthma and you work (or worked) with any of these substances, you may have grounds for a claim.
The Legal Test for an Occupational Asthma Claim
A successful claim must show three things:
- Your employer owed you a duty of care — this is automatic for employees, and also applies to many subcontractor or agency arrangements
- They breached that duty — for example by failing to control exposure to a known sensitiser, not providing appropriate respiratory protection, or not carrying out health surveillance
- That breach caused (or materially contributed to) your asthma
For asthma caused by a known sensitiser, the law is generally on the claimant’s side. Employers have been required since 2002 under the Control of Substances Hazardous to Health Regulations (COSHH) to identify asthma-causing substances, assess the risk, control exposure to the lowest reasonably practicable level, and provide health surveillance for at-risk workers. Failure to do any of these is usually a breach of duty. See our proving liability guide for the legal framework.
What Compensation Could You Receive?
Occupational asthma compensation depends on the severity of the asthma, its impact on work and daily life, and whether it has resolved or is permanent. Typical ranges:
- Mild asthma that resolves once exposure ends — typically £10,000 to £20,000
- Moderate asthma with ongoing symptoms but manageable on regular medication — typically £20,000 to £40,000
- Severe asthma with significant disability and frequent exacerbations — typically £40,000 to £70,000
- Asthma with permanent inability to work in the original trade — typically the upper end of the above plus substantial loss-of-earnings damages
Loss-of-earnings damages are often the biggest part of an occupational asthma claim. If you can no longer work as a baker, paint sprayer, or healthcare worker because of asthma developed at that job, the compensation for lost future earnings (including loss of pension and reduced earning capacity) can far exceed the general damages figure. For working-age claimants forced to retrain or take lower-paid work, six-figure settlements are common.
Who Can You Claim Against?
You claim against the employer (or employers) whose breach of duty caused the asthma. Where multiple employers are involved — for example a baker who worked at several bakeries — claims may be brought against each in proportion. Where the employer no longer exists, the Employers’ Liability Tracing Office can usually find the relevant historic insurer.
Government Schemes
Occupational asthma is a “prescribed” industrial disease for the purposes of government schemes. You may be able to claim Industrial Injuries Disablement Benefit alongside a civil claim — this is a weekly DWP benefit paid irrespective of fault. Eligibility requires that the asthma was caused by one of the substances on the prescribed list (which covers most common occupational asthma triggers).
Time Limits
You have three years from your date of knowledge — the date you first knew (or reasonably should have known) that your asthma was caused by your work. This is usually the date a doctor (often a respiratory consultant or occupational physician) made the link. For occupational asthma the date of knowledge can be tricky to pin down because symptoms often develop gradually over months or years before a definitive diagnosis is made. See our time limits guide for the rules in full.
Evidence That Strengthens an Occupational Asthma Claim
A solicitor will obtain everything you need. Strong claims usually include:
- Complete work history covering the period when exposure occurred — dates, employers, roles, substances handled
- Description of the work environment — ventilation, respiratory protection provided (or not), training given (or not)
- Health surveillance records (or their absence) — under COSHH employers should be doing regular respiratory checks for workers exposed to asthma-causing substances
- Material safety data sheets (MSDS) for the substances you handled
- Names of colleagues who can confirm working conditions
- Your medical records, including diagnosis date and any specific tests (peak flow records, methacholine challenge, specific IgE testing, serial peak flow measurements)
- Records of how the asthma has progressed and whether symptoms improve away from work and worsen on return
- Any HSE inspection reports for the workplace
Serial peak flow measurements — recording your breathing several times a day for two to four weeks both at work and away from work — are particularly powerful evidence and may already have been done by your respiratory consultant. Our evidence guide explains the wider picture.
Why Diagnosis Timing Matters
Occupational asthma is potentially reversible if the worker is removed from the trigger early enough. The longer the exposure continues after symptoms develop, the more likely the asthma is to become permanent. This is why employers have a positive duty to identify symptoms early through health surveillance and remove affected workers from the exposure — not just compensate them later.
A claim that includes specific allegations about a failure to act on early symptoms — for example, an employer ignoring a worker’s reports of breathing problems and leaving them in the same role for years — tends to attract higher damages because it shows the avoidable additional harm.
No Win No Fee Occupational Asthma Claims
Occupational asthma claims run on a no win no fee Conditional Fee Agreement. You pay nothing upfront, nothing during the case, and nothing if the claim fails, provided you keep to the terms of your agreement. If the claim succeeds, the success fee — capped by LASPO 2012 at 25 per cent of general damages and past losses (future losses excluded) — is deducted from your compensation. See our how no win no fee works guide.
Common Questions About Occupational Asthma Claims
I am a baker and developed asthma after 15 years of work. Is that a claim?
Very likely. Flour dust is a well-recognised cause of occupational asthma. Under COSHH 2002, bakeries are required to assess flour dust exposure, control it as far as reasonably practicable, and carry out health surveillance for bakers. Most claims of this kind turn on whether the bakery did any of those things adequately. The case is usually strong if there is no documented health surveillance.
My asthma improves when I am off work but I cannot afford to leave my job. Can I still claim?
Yes. You do not have to leave your job before claiming. In fact, continuing to be exposed can damage your case in two ways — first, your health continues to deteriorate, and second, the courts may consider your decision to stay when assessing loss of earnings. The right course is usually: see your GP, get a referral to a respiratory consultant or occupational physician, ask for serial peak flow measurements to confirm the link, and then talk to a specialist solicitor about your options.
I am a paint sprayer and developed asthma from isocyanates. Are these well-known claims?
Yes. Isocyanate-induced asthma is one of the most common types of occupational asthma claim in the UK and the legal pathway is well established. Specialist solicitors will be very familiar with the relevant evidence (air sampling records, RPE provision, health surveillance) and these cases tend to move efficiently if the employer’s record-keeping was deficient.
Can I claim if my asthma was caused at a job I left 10 years ago?
It depends on the date of knowledge. If you have only recently been diagnosed with occupational asthma (or only recently understood that your old job was the cause), the three-year clock may have only just started. A free initial consultation with a specialist solicitor will give you a clear answer in a few minutes.
How long does an occupational asthma claim take?
Most cases settle within 12 to 24 months, depending on complexity. Cases involving multiple employers, disputed causation, or significant loss-of-earnings calculations can take longer. See our how long does a claim take guide.
Related Guides
Industrial Disease Claims — UK Compensation
Occupational Dermatitis Claims
Work-Related Emphysema & COPD Claims
Industrial Deafness Compensation Claims
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