Reporting Highlights

  • Invisible Danger: Formaldehyde, a colorless pungent gas, can cause cancer, breathing problems and reproductive harms.
  • Greatest Threat: Most of us face the highest risks in our homes, where formaldehyde is released by some types of furniture, gas stoves and other everyday products.
  • Our Testing: We found concerning levels of formaldehyde in furniture stores, inside a nail salon, in cars and at a dinner party.

These highlights were written by the reporters and editors who worked on this story.

The air was packed with savory and sweet aromas when I walked into my colleague’s Brooklyn apartment for dinner. The sizzle and pop of rice and green beans cooking on the gas stove blended with soft jazz coming from the TV. Candle flames danced and flickered.

But we weren’t gathering just to enjoy a late-summer meal. We were trying to expose an uninvited yet ever-present guest — formaldehyde.

The invisible chemical can be harmless in small amounts, but in larger concentrations, it can cause headaches, dizziness, respiratory illness and asthma. It is also responsible for more cancer than any other toxic air pollutant.

Because of its importance to many industries, formaldehyde has proven difficult to regulate. This year, President Joe Biden’s administration finally appeared to make some progress, though it was modest. If the past is any guide, however, even those limited efforts are likely to hit a dead end after Donald Trump is inaugurated. Knowing our risks is essential to protecting ourselves, experts say. Last week, ProPublica published a tool to show how much formaldehyde is in the outside air.

But our biggest exposure happens indoors, so my colleagues and I set out to do our own testing.

We read thousands of pages of scientific studies and Environmental Protection Agency documents on the dangers of formaldehyde, and we learned the toxic chemical is nearly impossible to escape. Formaldehyde is in furniture and flooring. It is in the adhesives used in wallpaper and carpets. It’s given off by candles, fireplaces and gas stoves. And it’s in hair products and cosmetics.

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EPA scientists recently examined how low formaldehyde levels should be to ensure the chemical doesn’t trigger an allergic reaction, breathing problems or asthma symptoms, and the concentrations found inside the average home were far above that. Over a lifetime of exposure to the formaldehyde in an average home, a person’s risk of developing cancer is more than 250 times the risk level that the Clean Air Act sets as a goal. Even that number vastly underestimates the risk from cancer because the EPA did not factor in the chance of developing myeloid leukemia, the most common cancer caused by the chemical.

“It is everywhere, it is in everything,” University of California, Los Angeles researcher Nicholas Shapiro told me. Shapiro, who has spent years studying formaldehyde exposure, is working on a book, “Homesick,” that explores how formaldehyde, among other toxic chemicals in our homes, poses a danger to our health. “It is holding together our built environment and also chemically corroding us at the same time. It’s part of the fundamental paradox of the world that we’ve built, where this chemical is holding together our homes. We have built our society around it.”

My colleague Sharon Lerner and I traveled around New York City and New Jersey for weeks with equipment to measure the chemical’s presence.

The results proved concerning.

Out on the Town

Reporter Sharon Lerner fits a backpack with a pump that will allow for testing airborne formaldehyde levels before she heads outside. Credit: Topher Sanders/ProPublica

Sharon and I took a moment to wipe the July sweat from our brows as we got our testing equipment ready in a sprawling shopping center in Brooklyn. I placed a pump about the size of a large tape measure into Sharon’s backpack. The pump pulled in air through a two-foot rubber hose that extended out of the backpack’s main compartment.

I turned on the pump, which made a soft pneumatic sound. We were ready to ride the escalator up to an Ashley Furniture showroom in the Industry City mall.

“Can I help you guys find something?” a friendly salesperson asked.

“We’re just looking, thanks,” I replied.

We hoped the hose sticking out of Sharon’s backpack and the sound of the pump wouldn’t lead to more questions. For the next 20 minutes, we perused the showroom, opening cabinets, dressers and nightstands.

The store offers a wide range of budget furniture that can be made with foams, adhesives and wood composites that contain formaldehyde. These products go through a process called off-gassing, where chemicals they contain are released into the air over time. New furniture right out of the box has been shown to off-gas more than pieces that have been sitting out of their packaging for a while.

[Formaldehyde] is holding together our built environment and also chemically corroding us at the same time. It’s part of the fundamental paradox of the world that we’ve built, where this chemical is holding together our homes. We have built our society around it.”

—Nicholas Shapiro, a researcher at University of California, Los Angeles

Inside Ashley, it was hard to ignore the pungent fresh-furniture scent that wafted out of an opened cabinet or dresser. Sure, the furniture smelled, but we had no idea how much, if any, formaldehyde was present. The pump in Sharon’s backpack was collecting the air and any formaldehyde into a glass tube. As soon as we walked out, we placed the tube in a small cooler so we could send it to a lab for testing later.

We had other ideas about where to test. Sharon and another ProPublica colleague found a nail salon near New York City’s famed Canal Street. Some nail hardeners and polishes contain formaldehyde that may be listed on the product label as formalin or methylene glycol, according to the Food and Drug Administration. Also some nail polishes contain a toluenesulfonamide-formaldehyde resin that’s used to make the polish more resilient and adhere better to fingernails.

Standing on the busy sidewalk outside the salon with tourists buzzing by, I helped prepare the testing equipment. Once Sharon was inside, an employee soaked her hands and nails, then slathered them with goos, gels and paints. The air was acrid. The employee wore a disposable face mask, but other workers were unmasked as they clipped, sanded and shellacked customers’ nails.

A week or so later, I visited a Raymour & Flanigan furniture store in northern New Jersey. The sales folks didn’t pay much attention to me, so I didn’t have to worry about having an awkward conversation about the sound of the pump in my backpack. I walked around for more than 20 minutes, opening nightstand and dresser drawer.

Sharon and I stopped by a mall store that sells luxury soaps and lotions. We visited a cosmetics shop, a carpet store and a candle specialist. We packed up the air samples we collected and sent them to a certified industrial hygiene lab in Syracuse, New York, and waited.

The curly-haired woman examines a tall wall of carpeting. She’s using one hand to hold the end of the tube coming out of her backpack so it’s pointing straight out.
The air pump in Sharon’s backpack collects a sample as she browses a New Jersey carpet store. Credit: Topher Sanders/ProPublica

The EPA has determined that continuous daily exposure to concentrations of formaldehyde above 7 micrograms per cubic meter of air may cause decreased lung function, trigger allergic reactions and worsen asthma symptoms. Children and older people with asthma can be especially sensitive. It can be hard for doctors to identify formaldehyde as the reason for these kinds of reactions because it doesn’t linger in our bodies and there isn’t a medical or laboratory test that can accurately measure the amount of formaldehyde you may have been exposed to.

The chemical’s impact on our bodies can intensify dramatically the longer we are exposed. For instance, the EPA found that exposure to any amount of formaldehyde above a tiny concentration (0.09 micrograms per cubic meter) elevates people’s lifetime cancer risk beyond the goal the agency set. If the agency included the risk of developing myeloid leukemia in that calculation, that tiny concentration would be even smaller (0.023 micrograms).

When the lab emailed me the results, it revealed that our air sample from Ashley contained the highest levels of formaldehyde in our testing — 13 times the amount the EPA says is low enough to prevent issues like asthma, decreased lung function and respiratory irritation. Other results were also concerning. The nail salon had a concentration more than 6 times the level the EPA says would prevent breathing problems. Raymour & Flanigan’s concentration was more than 7 times the safe level. Federal regulators have set limits on how much formaldehyde some composite woods can release. But those limits are still well above the level EPA scientists established to prevent allergic reactions and other health problems.

A person’s risk depends not just on the chemical’s concentration but on how long they’re exposed. At the places we went, Sharon and I had been exposed to those concentrations for a matter of minutes, but the stores’ employees spend hours every workday breathing in the chemical.

In response to questions from ProPublica, Ashley Furniture spokespeople said the company follows all laws and regulations for furniture manufacturing.

“Given the many factors that contribute to air quality and the presence of formaldehyde, it would be impossible to say whether the furniture located in the store you visited contributed to your findings,” one wrote to ProPublica. The company also claimed that a 2011 survey of New York City found concentrations of formaldehyde in the surrounding neighborhood that were even higher than we had found in the store. But the survey actually found formaldehyde levels of only 1.5 micrograms per cubic meter in the area, a tiny fraction of the 91 micrograms ProPublica found in the furniture store.

Formaldehyde doesn’t linger in our bodies and there isn’t a medical or laboratory test that can accurately measure the amount you may have been exposed to.

Raymour & Flanigan did not respond to questions.

One of the more disturbing results was from the dinner party at the Brooklyn apartment of my ProPublica colleague. The lab tests showed the concentration of formaldehyde was nearly 12 times the level the EPA set to protect against breathing problems and other health issues. Formaldehyde is a byproduct of combustion, and we suspected that the gas stove and candles were largely to blame for the high levels of the chemical that evening.

Like anyone, I couldn’t help but wonder how much formaldehyde might be present in my own home.

Inside the House

About two months before we started the testing, my wife and I purchased a kid-sized work desk for our 10-year-old daughter’s bedroom to give her a place to do homework, create art and make those annoyingly messy Rainbow Loom bracelets.

When I opened the box for the desk, I was hit with the familiar smell of budget furniture. I had no idea I was inhaling a chemical mixture that may have included formaldehyde.

It took me longer than it should have to assemble the desk, but when I finished I got a huge hug from my daughter. She loves it.

Now I was curious about how much, if any, formaldehyde was lingering in her room, which she shares with her 5-year-old sister.

According to the Department of Housing and Urban Development’s American Healthy Homes Survey, the average level of formaldehyde inside an American home is 23.2 micrograms for every cubic meter of air. The survey found that about 10% of homes have levels above 41 micrograms, which is almost 6 times the concentration the EPA set to protect against respiratory problems.

Americans spend most of their time inside, and for decades we’ve worked hard to engineer ways to insulate and seal off our homes from the outdoor heat and cold. But that insulation works to trap formaldehyde in our homes, and older insulation might itself contain the chemical.

I placed a formaldehyde testing badge in my daughters’ room. The badges don’t draw air into them like the pump Sharon and I used at Ashley Furniture. They are intended to be worn by a worker or to rest in an area so that they collect samples from the air that simply passes by them. I put another badge in our kitchen, where we have a gas stove.

The lab results showed that my daughters’ room contained formaldehyde at 19 micrograms per cubic meter, one of our lower results, but still nearly 3 times the threshold the EPA set to prevent respiratory problems. I couldn’t help but wonder what the measurements would have been had we tested the room right after I assembled her cute new desk, instead of months afterwards. Our home’s kitchen recorded a level of 25 micrograms per cubic meter, also well above the EPA’s threshold.

Our testing hardly meets the rigor of scientific research. But plenty of scholarly studies have confirmed formaldehyde’s presence in our everyday lives and mirror our findings. Researchers have found unhealthy concentrations of the chemical in child care centers, funeral homes and even bakeries. A 2016 study in Atlanta found portable and traditional classrooms had levels more than 3 times the EPA’s target. And research dating back decades has frequently found high concentrations in people’s homes, with sources including wooden toys, baby cribs, arts and crafts supplies, and air fresheners.

ProPublica reporter Topher Sanders wears a backpack fitted with a formaldehyde monitor through a retail store. Reporters also placed formaldehyde testing badges in cars and in Topher’s daughter’s bedroom. Credit: First image: Topher Sanders/ProPublica; second image: Sharon Lerner/ProPublica; third image: Topher Sanders/ProPublica

Two flashpoints over the last 20 years have generated intense scrutiny of the dangers of formaldehyde. In the first, researchers found in 2007 that Federal Emergency Management Agency trailers that served as emergency shelters for many displaced by hurricanes Katrina and Rita reeked of formaldehyde. Some of the trailers in Mississippi and Louisiana had as much as 635 micrograms per cubic meter — more than 5 times the amount of formaldehyde we found in the Ashley Furniture store. Residents complained of breathing problems, nosebleeds and headaches.

One of the more disturbing results was from the dinner party at the Brooklyn apartment of my ProPublica colleague. The lab tests showed the concentration of formaldehyde was nearly 12 times the level the EPA set to protect against breathing problems and other health issues.

The second flashpoint came in 2015 when a “60 Minutes” investigation revealed that laminated flooring products from the popular company Lumber Liquidators were off-gassing significant concentrations of formaldehyde. Those revelations led to years of lawsuits, new EPA rules and a $33 million criminal penalty assessed by the Department of Justice after the company lied to investors in official filings about there being formaldehyde in its products.

Other studies have confirmed that the poor are disproportionately exposed to high concentrations of the chemical. Shapiro, the UCLA researcher, spent two years talking to more than 200 people who were connected to or lived in FEMA trailers. He said the well-to-do can afford to live in homes with enough ventilation, space and technology to reduce their exposure to formaldehyde.

The chemical’s presence in our lives and the way it is regulated, he said, ensures it “is going to continue to disproportionately make lower-income people sick.”

So sure, formaldehyde is in our homes. But when you walk out the door and drive away, you get a reprieve, right? Unfortunately, I learned through this reporting that no, you might not. When you get in your car, formaldehyde may be along for the ride.

On a Drive

In cars, formaldehyde adhesives can be found in the dashboards, seat coverings, flooring materials, carpeting, door trim, window sealant and armrests. And just like furniture, the highest levels of formaldehyde are found when cars are fresh off the assembly line.

Last year, the European Union set limits on the amount of formaldehyde new cars and other consumer products are allowed to release. New vehicles must not emit more than 62 micrograms per cubic meter, a level that’s 8 times the concentration the EPA says is safe to avoid breathing problems and other harmful effects. In coming up with the standard, the European Commission said it tried to protect the public’s health while also “limiting the socio-economic burden and need for technological changes for a wide range of industries and sectors.” The U.S. has no limit for new cars.

Sharon and I took our testing equipment on the road. The employees at a Tesla dealership we visited in north New Jersey were kind and welcoming. They let us take the Model S for a 30-minute test drive. We played around with the car’s gadgets while running the air conditioning and letting our formaldehyde pump collect samples.

The vehicle was one of five we test drove. None would have violated the EU limit, but all of them registered formaldehyde readings above the EPA’s threshold for preventing respiratory problems.

The Tesla had the most formaldehyde, at 38 micrograms per cubic meter — 5 times the level EPA’s scientists set to avoid causing respiratory problems. A Honda Odyssey, one of the bestselling minivans in the country, had 34 micrograms. A Toyota Corolla, the popular compact sedan known for its reliability, contained 29 micrograms.

A spokesperson for Honda said the company is an industry leader in reducing volatile organic compounds like formaldehyde inside car cabins.

The Odyssey is “compliant with all applicable international regulatory values for vehicle interior VOC’s,” the spokesperson wrote, referring to volatile organic compounds.

Tesla and Toyota did not respond to ProPublica’s questions.

Even older cars can still emit formaldehyde. My family’s 4-year-old sedan registered 39 micrograms per cubic meter on a sunny July day that reached 93 degrees. That’s higher than any of the new cars we tested.

We were able to get results from 19 places where we tested the air. In all of them, formaldehyde concentrations were higher than the level the EPA set to protect people from experiencing asthma symptoms, allergic reactions and other breathing problems. Those venues included a high-end store selling personal care products, a well-known candle shop and a big-box building supplies retailer.

Karen Dannemiller, an environmental health scientist and associate professor at Ohio State University, studies the effects of chemicals on the indoor environment. She has also researched how smartphones could be used to help measure indoor formaldehyde levels. She said learning about the impact and prevalence of formaldehyde can be eye-opening.

“I think it can be overwhelming to hear all this information because obviously we all want to protect our families,” she said. The most important thing, Dannemiller said, is to consider how our purchases and choices impact our homes “and just do the best that we can to improve the health of our indoor spaces.”