Asthma in the workplace - what do I need to know?

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What is asthma?

Asthma is a debilitating disease affecting around 5.4 million people in the UK and leading to nearly 1,500 deaths a year (Asthma UK figures).  

Asthma is a long-term condition affecting the airways into and out of our lungs. When someone with asthma comes into contact with an asthma trigger, it can cause:

  • The muscle walls around the airways to tighten so those airways narrow;
  • Swelling and inflammation of the lining of the airways;
  • A build up of mucus/phlegm, narrowing the airways further.

These in turn can lead to an asthma attack, with typical symptoms include wheezing, coughing, chest tightness and/or shortness of breath.

Occupational asthma is an allergic reaction that can occur in some people when they are exposed to substances, for example flour, wood dust or chemicals in the workplace. These substances have in turn been characterised as “respiratory sensitisers” or “asthmagens”.

When the occupational asthma sufferer is removed from the sensitiser the problem can disappear. However, in some cases occupational asthma can become a permanent problem for sufferers. There are substances in the workplace that can also worsen the symptoms of a person who already has the disease.  This is known as work aggravated asthma. The Health and Safety Executive (HSE) have produced an “asthmagen compendium” which provides lists of substances known to or suspected of causing occupational asthma (

What are the causes of occupational asthma?

The risk of developing occupational asthma can be higher in certain industries/workplaces where particular asthmagens are known to exist. Professions reporting higher rates of occupational asthma include being a:

  • Baker;
  • Vehicle spray painter;
  • Solderer;
  • Woodworker;
  • Healthcare worker;
  • Laboratory animal worker;
  • Agricultural worker;
  • Engineering worker; and

In most office environments the risk of occupational asthma is low. Of those who become sensitised to particular asthmagens, not all will go on to develop asthma. It is not uncommon for those whose lungs have become hypersensitive to have further attacks triggered by even very low-level exposure to the particular substance.

What substances are present in the workplace that can affect asthma sufferers?

In the general office environment, some asthma sufferers have found they are particularly sensitive to solvent vapours, dust, cleaning agents, paint fumes, pollens, moulds and even changes in temperature.

How can I find out if my workplace presents a risk to asthma sufferers?

A COSHH assessment should highlight if there is any risk of exposure to a number of the likely respiratory sensitisers in your workplace. Sickness and absence records can also indicate whether you could have a potential issue with occupational asthma. Where a number of asthma cases are identified, further investigation into the reasons for these is needed. If an adult develops asthma for the first time in their life, it is possible something in the work environment could be a cause.

How can occupational asthma be controlled in the workplace?

COSHH requires you to ensure your employee’s exposure to a sensitiser is either prevented or, where this is not reasonably practicable, adequately controlled. The HSE suggest strategies such as:

  • Modifying the method of work to eliminate exposure to the hazardous substance;
  • Substituting the sensitiser for another substance (of equal or less harm);
  • Enclose the process (and provide better extraction); and
  • Changing handling procedures that minimise the escape of hazardous materials.

If prevention is not possible you could reduce exposure by using personal protective equipment (PPE). Whatever action you take to reduce the risk of occupational asthma it is important that staff know about the procedures taken to minimise this risk and that they are properly trained in using PPE.

What guidance and legislation exists?

The management of occupational asthma is specifically covered under the HSE Approved Code of Practice for COSHH, Appendix 3 - Control of substances that cause occupational asthma. This Appendix applies to employers, the self-employed and employees (

Other HSE resources include:

About asthma- Asthma - HSE

Working with substances hazardous to health: A brief guide to COSHH (

There are also a range of trade specific guidance documents published on the HSE website.

This guide is of a general nature; specific advice can be obtained from Assurity Consulting by calling tel. 01403 269375 or by email

Assurity Consulting is the UK's leading independent compliance consultancy specialising in workplace health, safety and environmental solutions. We have over 30 years' experience of helping customers of all sizes, from across all sectors, manage their compliance responsibilities, making sure that their organisation is compliant, their employees are safe, their processes are cost effective and their management team is in control.