Why firefighters are at risk

In 2022 IARC evaluated occupational exposure as a firefighter and classified it in Group 1, carcinogenic to humans. Contaminants from smoke settle on skin and kit and can be absorbed or breathed in long after a fire is out. Heavy protective clothing, heat and sudden maximal effort put enormous strain on the heart.

Repeated exposure to distressing incidents adds psychological risk. Many fire services now treat contamination control, fitness and mental health as part of operational safety.

01Cancer-causing contaminants

Smoke contains many toxic and carcinogenic substances. Exposure continues during overhaul, through contaminated gear, and in vehicles and stations if kit is not cleaned. Reducing exposure at every stage is the aim, not only during firefighting.

What helps

  • Wear breathing apparatus throughout firefighting and overhaul, not only in heavy smoke.
  • Do gross decontamination of kit at the scene and bag contaminated gear for transport.
  • Wash exposed skin as soon as possible and shower soon after the incident.
  • Keep contaminated kit out of cabs, living quarters and homes.

02Heart strain and heat

Sudden heavy exertion in heat and protective clothing raises heart rate and body temperature sharply. The NHS lists chest pain, breathlessness and pain spreading to the arm, jaw or back as heart attack warning signs. Heat exhaustion can progress to heat stroke.

What helps

  • Keep up regular aerobic fitness and strength training.
  • Have regular medical checks including blood pressure and cholesterol.
  • Rotate crews, rehydrate and cool down in rehab areas at prolonged incidents.
  • Report chest pain, unusual breathlessness or dizziness immediately, never work through it.

03Trauma and PTSD

The NHS explains that post-traumatic stress disorder can develop after frightening or distressing events, with flashbacks, nightmares, avoidance and feeling on edge. Repeated exposure, rather than a single incident, often builds up.

What helps

  • Use structured defusing and peer support after difficult incidents.
  • Talk to occupational health early if sleep, mood or temper change.
  • Keep up connections and activities away from the service.
  • Use trauma-focused therapies if offered; they are effective.

Weekly checklist for firefighters

  • Clean and inspect kit after every incident.
  • Shower and change soon after every fire.
  • Train for aerobic fitness and strength at least three times a week.
  • Drink water steadily on shift, more after incidents.
  • Check in with a colleague after a difficult call.
  • Keep your annual medical up to date.

When to see a professional

  • Any chest pain, palpitations, fainting or unusual breathlessness.
  • A persistent cough, unexplained weight loss or a new lump.
  • Flashbacks, nightmares, irritability or numbness lasting more than a month.
  • Skin changes or sores that do not heal.

Call emergency services for chest pain, especially with sweating, breathlessness or pain spreading to the arm, jaw or back.

Where ONU fits

ONU brings your sleep, activity and recovery trends together, so you can see how night calls and heavy incidents affect your sleep and recovery. It does not assess cardiac risk, contamination or PTSD, and it does not replace service medicals or occupational health.

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Common questions

Is firefighting classified as causing cancer?

Yes. In 2022 the International Agency for Research on Cancer classified occupational exposure as a firefighter as carcinogenic to humans (Group 1).

Why is decontamination after fires so important?

Contaminants stay on kit and skin after the fire and can continue to be absorbed or inhaled. Cleaning skin and kit quickly reduces total exposure.

Why do firefighters have heart attacks on duty?

Sudden maximal exertion, heat and heavy gear put extreme strain on the heart, which can trigger events in people with underlying heart disease. Fitness and regular checks reduce the risk.

Sources and further reading

Educational information drawn from the public-health sources listed on this page. It is not a diagnosis, a treatment plan or a guarantee that you will avoid an illness or injury. ONU does not diagnose, treat or prevent disease. Speak to a qualified professional about anything that concerns you, and follow the rules of your employer, sport or local health service.