Firefighters and Cancer

The Fire Isn't What's Killing Firefighters Anymore

In 2025, the International Association of Fire Fighters added 311 names to its Fallen Fire Fighter Memorial. 247 of them — 79.4 percent — died of occupational cancer.

Not smoke inhalation. Not collapse. Not the things the job has always been understood to carry. Cancer, contracted at work, years after the calls that caused it.

That number has been climbing for two decades. The IAFF put cancer at 66 percent of career line-of-duty deaths across 2002 to 2019. It is now approaching eight in ten. In Canada, where presumptive coverage is broader and the tracking more complete, occupational cancer accounts for roughly 94 percent of professional firefighter line-of-duty deaths.

The fire service has a line-of-duty death problem that mostly does not happen on the fireground. It happens in oncology wards, quietly, ten and twenty and thirty years after the exposure.

It took until 2022 to say it plainly

In July 2022, the International Agency for Research on Cancer — the World Health Organization body that decides what counts as a carcinogen — reclassified occupational exposure as a firefighter into Group 1: carcinogenic to humans. The same category as asbestos, benzene, and tobacco smoke.

Group 1 is not a warning about a possible risk. It is a finding that the causal link is established. IARC found sufficient evidence in humans for two cancers — mesothelioma and bladder cancer — and limited evidence for five more: colon, prostate, testicular, melanoma of the skin, and non-Hodgkin lymphoma.

The classification covers more than 15 million firefighters worldwide. It did not change the job. It changed what everyone is now obligated to admit about it.

The underlying numbers had been there a while. NIOSH's long-running study of career firefighters found a 9 percent higher rate of cancer diagnosis and a 14 percent higher rate of cancer death compared with the general U.S. population. Some cancers are far worse than that average suggests — testicular cancer at roughly twice the expected rate, mesothelioma at twice, prostate at 1.28 times.

A 9 percent bump sounds survivable. It isn't the whole story. Averages flatten a population where some members have thirty years of interior time and some have three.

Why the modern fire is worse than the old one

A house in 1975 was wood, cotton, wool, and plaster. A house today is polyurethane foam, vinyl, laminates, engineered wood, adhesives, and plastics — petroleum products, effectively a fuel load of solid gasoline.

When that burns, it produces polycyclic aromatic hydrocarbons, volatile organic compounds, hydrogen cyanide, benzene, formaldehyde, heavy metals, and ultrafine particulates. Add the asbestos still sitting in older building stock, the brominated flame retardants in furniture, and the diesel exhaust idling in the bay, and the exposure profile of a routine room-and-contents fire looks nothing like the one the job was built around.

Structures also burn hotter and reach flashover faster than they did a generation ago. More heat, more synthetic fuel, more product of combustion — driven into gear, onto skin, and into the cab on the ride back.

The exposure doesn't end at the fire

This is the part that has reshaped best practice over the last decade. The dangerous window isn't only the working fire. It's everything after it.

Overhaul is when masks come off and the atmosphere still holds carcinogens that no longer announce themselves with visible smoke. Contaminated turnout gear keeps off-gassing in the cab, in the apparatus bay, in the bunk room. Soot on the neck and jaw — thin skin, no hood coverage, elevated body temperature, open pores — absorbs. Gear stored next to living space contaminates living space.

The hazard is cumulative and it follows the crew home.

Turnout gear itself is now part of the conversation. PFAS — the "forever chemicals" used for moisture and thermal barriers in structural PPE and historically in firefighting foam — have been detected in gear and in firefighters' blood, and are the subject of active litigation and ongoing standards work. Research on so-called PFAS-free alternatives is still catching up; at least one recent study warns that some substitutes carry their own chemicals of concern. This one is unresolved, and anyone claiming otherwise is selling something.

What we still don't know

The research base has a hole in it. Most of the foundational cancer studies looked at large career departments in big cities. That leaves out the majority of the American fire service: volunteers, small rural departments, and combination systems. It also badly underrepresents women firefighters, whose reproductive and breast cancer risks are only now getting serious study.

That gap is what the National Firefighter Registry for Cancer exists to close. NIOSH launched it in 2023 to collect work history, exposure, and health data from firefighters across the whole service — paid and volunteer, active and retired, with cancer or without. It passed 50,000 enrollments in 2026, with more than 165 departments reaching "Gold Helmet" status by enrolling at least half their active members.

Fifty thousand is a real milestone and still not enough. Enrolling takes about half an hour. It is, for most firefighters, the single highest-leverage thing they can do for the generation behind them.

What actually reduces the risk

The encouraging part of this research is how much of it points at changes that cost almost nothing.

Wear SCBA through overhaul, not just through knockdown. The IAFF calls it "the single most protective voluntary activity a fire fighter can complete." The air is worst when it looks safest.

Do wet gross decon on scene. NIOSH research led by Kenneth Fent compared methods directly: soap, water, and a brush removed about 85 percent of PAHs from gear. Dry brushing removed 23 percent. A leaf blower removed 0.5 percent. Cleansing wipes cut PAHs on exposed skin by roughly 54 percent — worth doing, not a substitute for a shower.

Exchange the hood when you come out of the IDLH. It's the most contaminated, most skin-adjacent piece of gear on the body.

Shower within an hour of getting back. Not after the report.

Keep contaminated gear out of the cab and out of the living space. Second sets, gear rooms with separate ventilation, and clean-cab policies exist for exactly this reason.

Clean and inspect PPE to standard. NFPA 1850 now governs selection, care, and maintenance of structural turnout gear and SCBA, consolidating what the service knew as 1851. Gear that is never cleaned is a carcinogen reservoir worn against skin.

Stage upwind and uphill, and shut the motors down. Diesel exhaust is a Group 1 carcinogen on its own.

The part that isn't technical

None of this works against a culture that treats a blackened helmet as a résumé.

That culture made sense when the hazard was heat and collapse and the evidence of hard work was soot. It does not survive contact with what we now know. A dirty helmet in 2026 is not a record of courage. It is an exposure you are still carrying.

The generational shift underway in the fire service — clean cabs, hood swaps, decon buckets on the tailboard, guys who shower before they eat — is not softness. It's the same instinct that put the first SCBA on a nozzle firefighter over the objections of everyone who had done it without one.

The job is going into places people are trying to get out of, and then coming back out. Cancer is the part of that job that takes twenty years to come back out of. It deserves the same seriousness we give the first twenty minutes.

Sources: International Agency for Research on Cancer, Monographs Volume 132 (2022); International Association of Fire Fighters, Fire Fighter Cancer Awareness Month materials (2026); CDC/NIOSH National Firefighter Registry for Cancer; Firefighter Cancer Support Network; Fent et al., Journal of Occupational and Environmental Hygiene.