Occupational asthma remains a serious workplace health issue in the UK, especially in jobs that involve regular exposure to dusts, fumes, sprays or chemicals. The Health and Safety Executive (HSE) estimates that there are around 22,000 new cases of self-reported breathing or lung problems caused or made worse by work over a three-year period. A substantial minority may be work-related asthma. Concern remains high because respiratory sensitisation can be permanent, the early signs can be missed and exposure still occurs across a wide range of occupations.
Some of the best-known causes are familiar to employers: flour dust in bakeries, wood dust in joinery and construction, isocyanates in paints and coatings, and substances used in laboratories, healthcare and manufacturing. The problem is that respiratory sensitisation can develop over time. Once a worker becomes sensitised, even a relatively low exposure may trigger symptoms.
That makes prevention far more useful than waiting for symptoms to become severe. COSHH assessment, exposure control, health surveillance and emergency planning all have a place in protecting respiratory health.
Occupational asthma is asthma caused by exposure to a substance at work. HSE distinguishes it from asthma that existed before employment but is made worse by workplace irritants. In both cases, work can be a major factor in whether symptoms appear or worsen.
Symptoms can include wheezing, chest tightness, coughing and breathlessness. They may start during a shift, but they can also appear later in the evening or early morning. That delay can make the connection with work less obvious to the employee and employer.
Isocyanates are a good example. They are used in polyurethane products, coatings, varnishes, two-pack paints and adhesives. HSE continues to identify isocyanates as a common cause of occupational asthma. Workers who become sensitised may face long-term restrictions on the type of work they can safely do.
The Control of Substances Hazardous to Health Regulations require employers to assess risks from hazardous substances and prevent exposure where reasonably practicable. Where prevention is not possible, exposure must be adequately controlled.
A useful COSHH assessment starts with the task rather than the product name alone. Spraying a coating can create a very different exposure from brushing it. Cutting or sanding a material may release dust that was not present during normal handling. Poor ventilation can increase exposure even when the quantity of substance used is small.
Safety data sheets can help identify respiratory sensitisers and other hazards, but they do not replace assessment of the actual work. Controls may include substitution, enclosure, local exhaust ventilation, changes to the process and suitable respiratory protective equipment. RPE should not become the automatic first choice where better controls are reasonably practicable.
Health surveillance may be required where workers are exposed to substances known to cause occupational asthma and there is a reasonable likelihood that disease could occur. HSE guidance for some isocyanate work recommends lung-function testing and questionnaires at defined intervals.
The purpose is to identify signs of ill health early enough for action to be taken. A pattern of coughing, wheezing or breathlessness around work should not be dismissed as a minor irritation. Early investigation can help establish whether exposure is contributing to symptoms and whether controls need to change.
Employers also need a clear route for workers to report symptoms without worrying that they will simply be removed from the job. A reporting system only works when concerns lead to competent review and practical action.
Some workplaces that use substances capable of irritating or sensitising the lungs also handle flammable liquids, aerosols or vapours. The health risk and the fire risk are separate issues, but the same work activity may create both.
For managers responsible for premises where flammable substances are used or stored, online fire risk assessment training can help build the knowledge needed to understand the fire risk assessment process. That training does not replace COSHH assessment or specialist advice on respiratory exposure. It supports a different part of the employer's risk-management duties.
Separating these assessments clearly can improve decision-making. A ventilation measure introduced to control vapours, for example, should be considered alongside ignition sources, extraction design and other fire precautions. One control should not create another unmanaged risk.
Prevention remains the priority, but employers also need arrangements for foreseeable emergencies. A severe asthma attack or acute inhalation incident can require rapid action while medical help is being arranged.
Workers with first-aid responsibilities need training that reflects the hazards present at the workplace. A Basic First Aid at Work course can provide a foundation for responding to common workplace emergencies, while site-specific arrangements should explain what to do when exposure involves particular chemicals or respiratory hazards.
Emergency information should be easy to access. Workers need to know how to raise the alarm, where to move an affected person, when emergency services are required and what information about the substance should be made available to responders.
Occupational asthma can also create reporting duties. Under RIDDOR, a diagnosed case may be reportable when the worker's job involves significant or regular exposure to a known respiratory sensitiser. Employers should check the reporting criteria rather than assuming every asthma diagnosis is reportable or, at the other extreme, treating work-related disease as a private medical matter with no safety implications.
Exposure records, health-surveillance records and details of control measures can help an employer identify patterns and demonstrate what action has been taken. They are also useful when a worker changes role, a process changes or a new substance is introduced. Good records should support prevention and review, not replace controlling exposure.
Occupational asthma is often associated with a limited group of substances and tasks, which means employers can identify many of the main risks before harm occurs. The practical work is straightforward: know what substances are present, understand how exposure happens, prevent or control it, monitor workers where health surveillance is needed and act when symptoms appear.
Respiratory health should also be considered alongside other risks created by the same process, including fire and emergency response. Keeping these controls connected without confusing their purpose gives managers a clearer picture of the work and the precautions it requires.
For workers, the difference can be significant. Early control may prevent sensitisation, while delayed action can leave someone unable to continue in the job they were trained to do. Employers should also review controls when substances, processes, ventilation arrangements or staffing change, because an assessment based on yesterday's work may no longer describe today's exposure.
MBTpg/MSM