Occupational asthma and work aggravated asthma

Most people consider asthma to be a disease of childhood.  However, the condition can occur in adults.  Should an employee experience symptoms of asthma it is important for their employer to consider if work could be causing the condition. 

There are two types of occupational asthma depending on what causes it:

This is the most common type of occupational asthma. Just like the many people who have their asthma symptoms triggered by things they are allergic to (allergens) in the home or outside (such as house dust mites, pollution or pollens), some people can have their asthma triggered by allergens in the workplace (such as flour dust, animal dander or car fumes). 

Allergens which cause occupational asthma are called ‘respiratory sensitisers’ because they can cause changes in the airways, making them ‘hypersensitive’. It takes a while for the immune system to become sensitive to an allergen, so employees may have been able to do their work for weeks, months or even years before they start having asthma symptoms. However, once they’ve become sensitive to an allergen, it can trigger asthma symptoms the next time they encounter it, even if it’s just a small amount of the substance.

Employees who have this condition may experience wheezing, coughing and chest tightness, other relevant symptoms to look out for are sneezing/runny nose and itchy and inflamed red eyes, as these symptoms often occur in the initial stages of the condition.  Employees may notice that these symptoms become worse when they’re at work or following a work shift, but ease when they’re away from work such as during annual leave. 

Chemicals commonly found in vehicle spray paint known as isocyanates; followed by substances found in bakeries (flour dust and additives which contain enzymes) are the most common substances responsible for causing allergic occupational asthma in the UK.  This puts employees who work in the car manufacturing industry and in bakeries in the high-risk group for the development of this condition. 


This is a non-allergic type of asthma, which happens when a person breathes in a chemical at their workplace, which irritates their airways causing chest symptoms. Irritant-induced asthma is not very common and usually happens when an employee has been exposed to high level of irritant chemicals, such as during an accidental chemical spillage in the workplace.

Examples of irritant chemicals include chlorine (used in swimming pools) and ammonia (which is a common cooling agent in refrigerators). Usually symptoms come on rapidly, if an employee is exposed to a high level of chemicals and they start to experience wheezing, coughing, breathlessness or chest tightness within 24 hours, then they should seek immediate medical attention.

Keeping employees safe 

Occupational asthma is the most common cause of adult onset asthma and makes up 9-15% of cases of asthma in adults of working age.

Employers need to ensure that they comply with the Control of Substances Hazardous to Health Regulations 2002 (COSHH), which state that if an employee is exposed to a substance hazardous to health, then the employer needs to ensure that such employees are under suitable health surveillance.

The Health and Safety Executive have provided guidance for employers on appropriate health surveillance for occupational asthma: http://www.hse.gov.uk/pubns/guidance/g402.pdf

Here at Medigold Health, we work in line with HSE guidelines to help keep people in work, Safe and well. We have a variety of options available to ensure that onsite and clinic testing are accessible for all of your employees while creating the least disruption as possible. We also work alongside organisations to introduce and maintain a robust health surveillance programmes. 

If you think your employees could be coming into contact with substances that could put them at risk of developing occupational asthma then please contact the team on 0845 127 8888