Focus Archive

Occupational Asthma

January 1998
Sheila Pantry, OBE

Asthma is a widespread disease of the general population, which can start at any age, but often starts in childhood. People with asthma have been subject to sensitisation of the airways, often by substances common in the environment. They will have sensitive airways all the time, but only get symptoms when they meet a trigger factor. Triggers vary between individuals, and include the original sensitiser and other environmental factors. The incidence of asthma has been rising in recent years. Its symptoms include wheezing, breathlessness, cough and a tight chest.

Occupational asthma is asthma caused by exposure to specific sensitising agents in the workplace. Its signs and symptoms are no different from "natural" or "environmental" asthma. Its incidence has also been rising in recent years as recorded by workplace ill-health reports, statutory compensation claims and insurance claims under employers' liability. In most cases it is a disease of short latency, starting on average only months after initial exposure. Some cases however occur almost immediately, and some only after decades of exposure.

Respiratory sensitisers

Respiratory sensitisers are substances, which, when inhaled, can trigger an irreversible allergic reaction, leading to asthma - an extremely distressing and potentially life-threatening disease. Most sufferers are so disabled by the illness that they have to change jobs to avoid coming into contact with the substance which triggered the disease and so are unable to continue working at all. Substances are found in a wide range of workplaces and industries, including vehicle paint spraying, foam manufacturing, food processing, electronic soldering and agriculture.

Employers are required by law to assess the risks to the health of their employees and to put in place control measures to reduce these risks to acceptable levels. The UK Health and Safety Executive as part of the Breathe Freely publicity campaign to prevent occupational asthma have updated the leaflet Respiratory sensitisers and COSHH: an employers leaflet (IND G 95 L). This leaflet briefly explains what respiratory sensitisers are and how they cause asthma and lists the substances responsible for most of occupational asthma. It also outlines to the employers the control measures they need to take to comply with the Control of Substances Hazardous to Health Regulations (COSHH) and the various amendments since 1994.

Two other guidance publications from HSE will also help - Preventing asthma at work: how to control respiratory sensitisers and Medical aspects of occupational asthma. The first publication reminds employers of their duties, under the COSHH Regulations, to protect employees from exposure to respiratory sensitisers and lays out specific procedures which should be followed to prevent workers developing occupational asthma. It also explains the causes and effects of respiratory sensitisation and gives a list of the most commonly used substances associated with the illness. The second publication Medical aspects of occupational asthma outlines causes and effects.

Information for the insurers

The Loss Prevention Council have produced a 40 page report Occupational Asthma to provide an appraisal of the situation for UK liability insurers of occupational asthma, which is associated with respiratory sensitisers. This requirement arose from another Loss Prevention Council review on "Occupational ill-health in Britain", coupled with knowledge of recent insurance claims information on occupational diseases.

The report indicates the scale of the problem. The annual incidence of occupational asthma in the UK is estimated at between 1500 and 4000 cases. These are the cases whose disability might qualify them for statutory benefit, and in consequence might appear as civil claims. The current number reported through all routes is about 1000, but under-reporting is significant. Reporting is expected to increase significantly over the next few years as a result of the Health and Safety Executive's Breathe Freely campaign.

The LPC report states that as a result of this annual incidence it is estimated that there is a large number of cases of occupational asthma present in the population, probably around 20,000. These have become sensitised at some point in the past. Their sensitisation remains but many may currently be free of symptoms. These represent a worrying potential backlog of claims which insurers might have to deal with.

The report continues that insurers should insist that users of respiratory sensitisers put in place adequate control measures to combat the problem of occupational asthma. In addition, they should be prepared to handle more claims in the medium term i.e. 10 years.

The LPC report covers a number of aspects of occupational asthma - the medical features are clearly laid out covering the standards and criteria for diagnosis, assessment of disability, the relationship to other respiratory diseases, irritant effects on respiratory function, and why normal asthma is made worse by work conditions.

There is further information on controlling occupational exposure to respiratory sensitisers, including details of various HSE and other publications such as manufacturers' and suppliers' datasheets. Occupational asthma is reportable under The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR). In the statistics chapter in the report LPC state that they are now in position to be able to predict the future of these diseases based on the current situation and projected future developments. This section assesses the available sources of data to reveal the true scale of the problem.

It is in the two final chapters - the implications for the UK Insurance industry and the conclusions and recommendations which makes compulsive reading. So further action is still needed:

In addition, to the above there is a very useful bibliography of further reading in the report which should be read by everyone who is aiming to secure a safer and healthier workplace.

To help in this quest for up-to-date validated and authoritative information there are a number of compact discs such as OSH-ROM, OSH-CD, and FIRE CD, available which give instant answers to these problems.

The products mentioned in this article are available for a free trial. Why not try these for yourself and check out the contents of these exciting sources of information against your own workplace needs?

Further information

Loss Prevention Council Occupational asthma, (SHE 13) ISBN 0902167 76-6, LPC, Melrose Avenue, Borehamwood, Hertfordshire WD6 2BJ UK, Tel: +44 (0) 181 207 2345 Fax: +44 (0) 181 207 6305

HSE publications available from HSE Books, P.O. Box 1999, Sudbury, Suffolk CO10 6FS UK, Tel: +44 (0) 1787 881165 Fax: +44 (0) 1787 313995