Occupational asthma is a type of asthma that is caused by exposure to substances in the workplace. This exposure can cause inflammation and narrowing of the airways, leading to symptoms such as coughing, wheezing, chest tightness, and shortness of breath. Occupational asthma can occur in people with no prior history of asthma or in those with pre-existing asthma that is worsened by exposure to workplace irritants.

Occupational asthma can be caused by a wide range of substances, including dust, chemicals, fumes, gases, and other allergens. Some common workplace irritants that can cause occupational asthma include:

• Animal substances, such as proteins from animal fur, dander, or urine
• Dust from grain, flour, or wood
• Chemicals such as isocyanates, formaldehyde, and solvents
• Cleaning products
• Fumes from welding or soldering
• Smoke from cooking or tobacco

Diagnosis of occupational asthma involves a medical history, physical exam, and tests such as lung function tests and allergy testing. Treatment typically involves removing the person from the source of the workplace irritant, if possible, and using medications such as inhaled corticosteroids, bronchodilators, and leukotriene modifiers to manage symptoms. In some cases, immunotherapy or allergy shots may be recommended.

Prevention of occupational asthma involves identifying and minimizing exposure to workplace irritants through measures such as engineering controls, personal protective equipment, and proper ventilation. Employers have a responsibility to provide a safe work environment and to educate their employees about workplace hazards and safety measures.

More than 250 workplace substances have been identified as possible causes of occupational asthma. These substances include:

• Animal substances, such as proteins found in dander, hair, scales, fur, saliva and body wastes.
• Chemicals used to make paints, varnishes, adhesives, laminates and soldering resin. Other examples include chemicals used to make insulation, packaging materials, and foam mattresses and upholstery.
• Enzymes used in detergents and flour conditioners.
• Metals, particularly platinum, chromium and nickel sulfate.
• Plant substances, including proteins found in natural rubber latex, flour, cereals, cotton, flax, hemp, rye, wheat and papain — a digestive enzyme derived from papaya.
• Respiratory irritants, such as chlorine gas, sulfur dioxide and smoke.

Asthma symptoms start when your lungs become irritated (inflamed). Inflammation causes several reactions that restrict the airways, making breathing difficult. With occupational asthma, lung inflammation may be triggered by an allergic response to a substance, which usually develops over time. Alternatively, inhaling fumes from a lung irritant, such as chlorine, can trigger immediate asthma symptoms in the absence of allergy.

The best way to prevent occupational asthma is for workplaces to control the workers' level of exposure to chemicals and other substances that may be sensitizers or irritants. Such measures can include implementing better control methods to prevent exposures, using less harmful substances and providing personal protective equipment (PPE) for workers.

Although you may rely on medications to relieve symptoms and control inflammation associated with occupational asthma, you can do several things on your own to maintain overall health and lessen the possibility of attacks:

• If you smoke, quit. In addition to all its other health benefits, being smoke-free may help prevent or lessen symptoms of occupational asthma.
• Get a flu vaccination. This can help prevent illness.
• Avoid nonsteroidal anti-inflammatory drugs (NSAIDS) and other medications that may make symptoms worse.
• Lose weight. For people who are obese, losing weight can help improve symptoms and lung function.

If you are in the United States and you have a job in a high-risk profession, your company has legal responsibilities to help protect you from hazardous chemicals. Under guidelines established by the Occupational Safety and Health Administration (OSHA), your employer is required to do the following:

• Inform you if you'll be working with any hazardous chemicals.
• Train you how to safely handle these chemicals.
• Train you how to respond to an emergency, such as a chemical spill.
• Provide protective gear, such as masks and respirators.
• Offer additional training if a new chemical is introduced to your workplace.

Under OSHA guidelines, your employer is required to keep a material safety data sheet (MSDS) for each hazardous chemical used in your workplace. This is a document that must be submitted by the chemical's manufacturer to your employer. You have a legal right to see and copy such documents. If you suspect you're allergic to a certain substance, show the MSDS to your doctor.

While at work, be alert for unsafe and unhealthy working conditions and report them to your supervisor. If necessary, call OSHA at 800-321-OSHA (800-321-6742) and ask for an on-site inspection. You can do this so that your name won't be revealed to your employer.