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Study Raises Concerns Over Flame Retardant Chemicals In Cars

Written By: Jerry Reynolds | May 14, 2024 10:39:36 AM

Well, here’s one more thing to worry about with your car:  Exposure to flame retardant chemicals in your seats, especially when it gets warm inside.  According to a new peer-reviewed study released last week in the journal Environmental Science & Technology, "vehicles are likely important sources of human exposure to potentially harmful flame retardants”.  These chemicals are added by car manufacturers to seat foam and other materials to meet a federal flammability standard set more than 50 years ago, in 1971.

In the study, 100 vehicle owners placed silicone bands in their cars for a week to measure the chemical levels inside. The study found that the concentration of those chemicals was two to five times higher in the summer compared to the winter.  The study did not look at specific makes and models of cars.

“Our research found that interior materials release harmful chemicals into the cabin air of our cars,” said lead author Rebecca Hoehn, a scientist at Duke University. “Considering the average driver spends about an hour in the car every day, this is a significant public health issue. It’s particularly concerning for drivers with longer commutes as well as child passengers, who breathe more air pound for pound than adults.”

tcip-flame-retardant-graphicCredit: Environmental Science & Technology , 2024.

From the study:

"Participants were invited to the study via an advertisement in the Green Science Policy Institute newsletter. Inclusion criteria included living in the United States and owning a vehicle of model year 2015 or newer. Interested participants submitted information about their vehicle model year, engine type, and zip code. Participants were selected to target a wide geographic distribution of vehicle locations as well as different engine types: ∼50% internal combustion engines (n = 49), 25% electric (n= 26), and 25% hybrid (n = 26). This study was reviewed by the Duke University Institutional Review Board and determined to be “exempt human subjects research” because it focused on the vehicles as subjects rather than human participants.

Samples were collected in both the winter and summer months to assess the effect of temperature on levels of FRs in cabin air. The first set of sampling kits was sent to 101 participants in February and March of 2022 for deployment from February to May, and a subset of participants (n = 54) were sent a second kit in July or August of 2022 for deployment between July and September. Each participant indicated the zip code where their vehicle was stored during the deployment of the silicone sampler and the date and time at which the sampler was deployed and removed. Deployment dates were used to extract average daily temperatures from the National Oceanic and Atmospheric Administration (NOAA) online Climate Database. (31) Daily temperatures were averaged over the 7-day course of sampler deployment to obtain an average ambient temperature experienced by each vehicle.

Vehicles in this study were primarily manufactured between 2015 and 2022, reflecting our interest in understanding FRs in recently manufactured vehicles. Vehicles were from locations across 30 different states, with the largest number located in California. Because of this wide geographic distribution and the sampling of a subset of vehicles in both winter and summer, we were able to study vehicles exposed to average ambient temperatures ranging from approximately −5 to 30 °C."

Consumer Reports Issues Statement and Launches Petition

Following the report, Consumer Reports issued a statement calling on the National Highway Traffic Safety Administration (NHTSA) to update its current flammability standard for vehicle interiors.  CR has also launched a petition to "Get cancer-causing chemicals out of cars". You can read the petition and sign it here.

“You may be able to reduce your exposure to flame retardants in your car by opening your windows and parking in the shade,” said co-author Lydia Jahl, a senior scientist at the Green Science Policy Institute. “But what’s really needed is reducing the amount of flame retardants being added to cars in the first place. Commuting to work shouldn’t come with a cancer risk, and children shouldn’t breathe in chemicals that can harm their brains on their way to school.”

Special thanks to the Green Science Policy Institute for bringing this issue to light.  I am sure much more will be learned in the days ahead.

Photo Credit: DimaBerlin/