EAST PROVIDENCE, R.I. (AP) -- Every time he rushed out on a fire call, East Providence Lt. Thomas Votta knew he put himself at risk for cancer. There are potential carcinogens in the smoke billowing out of a house fire, but also risks from wearing his chemically-treated gear.

Last month, the Rhode Island fire department became the nation's first to give the 11-year veteran and all his 124 fellow firefighters new gear free of PFAS, or perfluoroalkyl and polyfluoroalkyl substances.

Known as forever chemicals because of how long they remain in the environment, PFAS have been linked to a host of health problems, including increased risk of certain cancers, cardiovascular disease and babies born with low birth weights.

"We are exposed to so many chemicals when we go to fires," Votta said. "Having it inside our gear, touching or very close to our skin was very, very concerning. Knowing that's gone now, it gives us a little bit of relief. We're not getting it from every angle."

The PFAS in the multilayered coats and pants -- primarily meant to repel water and contaminants like oil and prevent moisture-related burns -- have been a growing concern among firefighters for several years.

Cancer has replaced heart disease as the biggest cause of line-of-duty deaths, according to the International Association of Fire Fighters, the union that represents firefighters and EMS workers. Firefighters are at higher risk than the general population of getting skin, kidney and other types of cancer, according to a study led by the American Cancer Society.

Firefighters are exposed to smoke from faster and hotter blazes in buildings and wildfires, many containing toxic chemicals like arsenic and asbestos. In addition to the PFAS in their gear, the IAFF is also concerned about firefighting foam that contains the chemical and is being phased out in many places.

"The question that is obvious to us is that why would we have carcinogens intentionally infused into our personal protective equipment?" IAFF General President Edward Kelly, who was elected in 2021 in part on a campaign to address PFAS dangers, said at a news conference this month.

It can be difficult to determine the cause of a firefighter's cancer since the disease can take years to develop and genetics, diet and other lifestyle factors can play a role, experts say. Where a firefighter works -- cities, suburbs or rural areas -- also can impact the level of exposure to toxins.

"That's good they're shining a light on the health of their workers," said Dr. Lecia Sequist, program director at the Cancer Early Detection and Diagnostics Clinic at Mass General Hospital.

"But I don't think the data is mature enough that we have a clear understanding of what the unique causes of cancer in firefighters might be that's different from the general population."

Still, health concerns among firefighters have sparked a flurry of lawsuits against makers of gear and PFAS chemicals. Seven states, including Massachusetts and Rhode Island, have passed laws banning PFAS in gear and two others introduced bills calling for bans, according to the IAFF.

The union has also targeted the agency that sets voluntary standards for firefighting gear and other safety requirements. In a 2023 lawsuit, the union accused the National Fire Protection Association, or NFPA, of setting standards that can only be met with PFAS-treated material and working with several gear makers to maintain that requirement -- something the association denied.

Last year, the agency announced new standards restricting use of 24 classes of chemicals including PFAS in gear -- though it is considering delaying the law until March to give companies more time to comply.

"The development of this new standard marks the most significant and complex shift in how firefighter protective gear is made in a generation," said NFPA spokesperson Tom Lyons.

Amid the state bans and legal fights, some of the largest gear makers are shifting away from PFAS. Smaller companies have also emerged marketing what they claim is PFAS-free gear. Hydrocarbon wax or silicone-based finish often replaces PFAS in the outer shell and removes it from the middle, moisture barrier.

The changing gear landscape is giving fire departments an opportunity to make the switch to safer alternatives.

Vancouver, Canada, purchased PFAS-free gear last year while Manchester, New Hampshire, bought new gear in March. Gilroy, California, and Belmont, Massachusetts, are in the process of making the switch, the IAFF said.

"We're trying to take every step possible to limit their exposure to the chemicals," said Manchester Assistant Chief Matt Lamothe.

But switching to PFAS alternatives hasn't been easy.

Since companies often don't list chemicals in gear, fire departments are often in the dark as to whether it's actually safer while also complying with heat stress, moisture and durability requirements. And PFAS-treated gear is still on the market, supported by the American Chemical Council, which argues these materials are the "only viable options" to "meet vital performance properties."

San Francisco was considering getting PFAS-free gear from one company until tests showed the chemical was present. The company addressed the problem and the fire department bought its first 50 of 700 sets this month.

"The biggest challenge has been trust -- or more accurately, the lack of it," said Matthew Alba, a San Francisco department battalion chief who is being treated for a brain tumor he blames on fighting wildfires.

In Quincy, Massachusetts, the department bought what it thought were 30 sets of PFAS-free gear, but independent tests revealed the chemical's presence.

"These last few months dealing with this issue has been frustrating, angry and truthfully sad seeing what these companies continue to pull," Tom Bowes, president of the IAFF local, told a news conference attended by dozens of Quincy firefighters this month.

Researchers at Duke and North Carolina State universities argue concerns over the new gear suggest the transition away from PFAS has been rushed -- potentially exposing firefighters to new chemicals and giving them gear that hasn't been proven safe.

"I've talked to fire chiefs, fire departments across the country, across the world, they're all dealing with it," said Bryan Ormond, a professor at North Carolina State and director of its Milliken Textile Protection and Comfort Center. "They're all trying to figure out ... how to move forward safely and protect our people because we don't necessarily know what the new gear is going to do."

But Graham Peaslee, an emeritus professor at the University of Notre Dame who tested gear for San Francisco and Quincy and is working with five other departments, said concerns about PFAS-free gear were a "scare tactic" from the chemical companies that want to keep selling their products.

In East Providence, testing showed the fire department's first attempt to buy PFAS-free gear contained flame retardants that pose increased cancer risk and didn't adequately protect from heat. A new supplier provided PFAS-free materials that offered the heat protection.

"It's a home run," Fire Chief Michael Carey said of the gear, which cost $658,000 and was paid for by pandemic funds.

"It takes a sizable weight off of my shoulders," he said. "I don't have to worry about them being in that gear and being exposed to a known carcinogen."