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Asthma is a respiratory condition that causes a narrowing of the airways in your lungs and trouble breathing. Occupational asthma happens when you inhale asthma triggers in your workplace — it’s also referred to as work-related asthma.

Breathing in fumes, gases, dust, or other harmful substances can all contribute to the development of occupational asthma. Symptoms are similar to other forms of asthma and include wheezing, shortness of breath, and chest tightness. In these cases, symptoms usually improve once you move away from the irritant at your workplace.

Keep reading to learn why occupational asthma develops, who’s at risk, and what can be done to prevent it.

Asthma is a chronic condition that causes inflammation in your airways. Asthma can have many underlying causes. For example, seasonal allergic asthma is caused by allergens like pollen or mold spores.

Occupational asthma is the most common work-related lung disease. It’s a specific type of asthma caused by breathing in irritants found where you work. It’s thought to make up as much as 15 percent of asthma cases in the United States.

Breathing in irritants can cause a sudden worsening of asthma symptoms called an asthma attack. Asthma attacks are caused by:

  • muscle spasms
  • mucus buildup
  • inflammation in your airways

Occupational asthma can be further classified into several categories.

Sensitizer-induced occupational asthma

Sensitizer-induced occupational asthma occurs when a specific substance triggers an allergic response that leads to asthma symptoms. It’s most often caused by repeated exposure to a trigger over months or years as opposed to an immediate reaction.

Sensitizer-induced occupational asthma makes up more than 90 percent of cases of occupational asthma.

Irritant-induced asthma

Irritant-induced asthma is directly caused by exposure to an irritating substance. It can develop in three ways:

  • within 24 hours after exposure to a high level of an irritant
  • after multiple exposures to medium or high levels of an irritant
  • after chronic exposure to low or medium levels of an irritant


Byssinosis, or brown lung, is a type of occupational asthma caused by inhaling hemp, flax, or cotton particles. It causes similar symptoms as other types of asthma.

In the United States, byssinosis typically develops only in people working with unprocessed cotton.

Occupational asthma causes the same symptoms as other forms of asthma.

Common symptoms include:

  • shortness of breath
  • chest tightness
  • wheezing
  • coughing, especially during exercise, laughing, and at night
  • fatigue
  • anxiousness
  • trouble talking

Less common symptoms that should prompt immediate medical attention include:

  • rapid breathing
  • lack of relief from your rescue inhaler
  • inability to fully breathe in or out
  • inability to speak coherently
  • confusion or agitation
  • blue tint to your face, fingernails, or lips

Occupational asthma is caused by inhaling:

  • gases
  • fumes
  • gases
  • dust
  • other irritants

More than 400 specific substances have been identified as potential triggers of occupational asthma, including:

  • wood dust
  • pesticides
  • cleaning agents
  • dusts
  • sprays
  • latex
  • cereal or flour
  • phenol-formaldehyde resin
  • chlorine
  • hydrochloric acid
  • ammonia
  • diesel exhaust
  • paint fumes
  • smoke
  • aluminum iodide

Some people are more likely to develop occupational asthma than others. Risk factors include:

  • having a relative with asthma or allergies
  • having allergies
  • smoking or regular exposure to secondhand smoke
  • having overweight
  • working a job that regularly exposes you to known irritants

The Centers for Disease Control and Prevention (CDC) recommends two important treatments for work-related asthma: avoiding triggers and controlling symptoms.

Continuing to breathe in irritants can cause your symptoms to get worse over time. If you develop a sensitivity to a particular substance, even breathing in small amounts may cause asthma symptoms.

Medical treatments

Medications to treat asthma can be broken into short-term and long-term treatments.

For short-term relief of an asthma attack, you may need to use:

  • short-acting beta-agonists
  • corticosteroids
  • anticholinergic agents

Medications for long-term control include:

  • inhaled corticosteroids
  • leukotriene modifiers
  • long-acting inhaled beta-2-agonists

Home remedies

For mild asthma, you may be able to treat your symptoms with home remedies. But keep in mind that none of these treatments should be used in case of an asthma attack.

  • Breathing exercises. A 2014 study in the journal Breathe found that breathing training may improve asthma symptoms and lower the need for rescue medication.
  • Dietary measures. Eating a nutritious diet can help you maintain your weight and reduce your risk of symptoms.
  • Exercising regularly. Exercise can help you strengthen your lungs and manage your weight. It’s important to have your asthma under control before starting a new exercise program.
  • Quit smoking. Smoking can make some asthma medications less effective and worsen your symptoms.

Some occupations can put you at an elevated risk of developing occupational asthma. Check out the list below for some common occupations that can increase your risk of asthma.

Keep in mind that this list doesn’t cover every occupation or irritant that may cause occupational asthma.

grain handlers
grain dust
mushroom cultivatorsmushroom spores
dental workers
healthcare workersglutaraldehyde
certain medications
sterilizing agents
service cleaners
pine products
acetic acid
cement workers potassium dichromate
timber millers
sawmill workers
wood finishers
wood machinists
western red cedar
cedar of Lebanon
California redwood
African zebrawood
African maple

Workers and employers can both take steps to reduce the development of occupational asthma.

Workers can try to reduce occupational asthma by doing one or more of the following:

  • quitting smoking (if you smoke)
  • getting the flu and COVID-19 vaccines
  • avoiding nonsteroidal anti-inflammatory drugs (NSAIDs) and medications that can make symptoms worse
  • managing your weight
  • removing yourself from exposure to irritants as soon as possible
  • treating asthma attacks early
  • taking medication as prescribed
  • letting your doctor know if you’ve been using your quick-relief inhaler more often than usual

Here’s what employers can do to help prevent occupational asthma for their employees:

  • minimizing workers’ exposure to chemicals and substances known to trigger asthma
  • using less harmful substances when possible
  • following Occupational Safety and Health Administration (OSHA) guidelines for acceptable exposure levels
  • providing proper protective and safety equipment for workers
  • educating workers on proper handling and safety

Occupational asthma is asthma caused by irritants in the workplace. Hundreds of types of irritants are known to trigger occupational asthma.

Occupational asthma symptoms often improve when you’re no longer exposed to the irritant. If it’s impossible to avoid the irritant, you may need to talk with your employer about changing locations at your worksite or consider finding another occupation to reduce your risk.