As the subject of countless news articles, talk show segments and even a major Mark Ruffalo film, the environmental and health harms of per- and polyfluoroalkyl substances (PFAS) are well-known. PFAS are associated with cancer, liver damage, obesity, infertility, reduced response to vaccines, more severe COVID-19 outcomes and more. Due to their widespread use in everyday products — from nonstick pans to raincoats — they lurk in virtually all of our bodies.
Years of rigorous peer-reviewed research have gone into investigating the risks of PFAS. However, few have questioned their benefits — until now.
Preceding their reputation as toxic “forever chemicals” was their reputation as “wonder chemicals.” They were heralded for making a wide range of products resistant to water, oil and stains. However, we heard from furniture textile manufacturers that the stain repellent finishes on their products don’t perform as promised. So, we decided to scientifically test the assumption that PFAS finishes prevent furniture stains.
Using droplets of coffee and salad dressing, we tested six PFAS-finished and three non-PFAS-finished furniture fabrics. Coffee stains washed out of PFAS-finished and unfinished fabrics alike with no significant staining. For oil-based salad dressing stains, PFAS-finished fabrics performed slightly better, but only under ideal conditions when there is a fresh coating of PFAS and when the stain was wiped up immediately. Departing from this ideal scenario — when the fabric has been worn with abrasion or the stain sits in the fabric for longer — we found that staining was worse than unfinished fabrics.
In all cases, fabric choice had a much larger influence on stain prevention. As textile manufacturers know, choosing darker textiles with visual texture helps mask stains. To have even a small benefit for some stain types, PFAS treatments need to be reapplied on the fabric over and over like lipstick or car wax. Each reapplication means increased costs, more exposure and contributes to already disastrous levels of contamination in the environment.
This isn’t the first instance of the advertised benefits of harmful chemicals coming up short. For decades, organohalogen flame retardants were added to all the nation’s furniture foam to meet a California flammability standard. This continued even when there was robust evidence of links between these chemicals and lowered IQ in children, cancer, hormone disruption and other health problems. It was simply assumed that the benefits outweighed the risks.
However, when the Green Science Policy Institute reviewed the fire-safety claims scientifically, they were nothing but hot air. Furniture with and without flame retardants burns similarly. In light of this and other evidence, the flammability standard was revised, and organohalogen flame retardants are no longer used in the majority of North American furniture. That means we are exposed to less of these chemicals, so our furniture is even safer than before.
In the case of PFAS finishes for furniture, there is limited to no benefit, certainly not enough to outweigh the risks. Continued use of PFAS on textiles creates exposure risks during manufacture, use and disposal, leading to health risks for workers, consumers and communities living near production sites as well as environmental harm.
The U.S. Environmental Protection Agency (EPA) has determined that even extremely low levels of PFAS in drinking water are unsafe and utilities across the country will soon be incurring the cost of upgrading their water treatment facilities. But, drinking water is only one source of exposure, so we should really be addressing the root cause and preventing PFAS from entering the environment in the first place.
The good news is that California, Colorado, Maine, Washington and other U.S. states have legislation passed or in progress to phase out PFAS in many textile applications, including furniture. Due to the size of California’s market alone, this should eventually make the whole country’s furniture PFAS-free.
However, our study should make scientists, manufacturers and lawmakers alike wonder what other uses of PFAS could be easily eliminated from products without any noticeable change in performance. Stopping non-essential uses of PFAS is crucial to reducing further exposure and health risk.
We don’t blindly accept chemical manufacturers’ claims about the safety of their products, so we shouldn’t blindly accept claims about their benefits, either. While we can sometimes achieve “better living through chemistry,” both the risks and the benefits of chemicals deserve scientific scrutiny.
Jonas LaPier is a Ph.D. candidate in Civil and Environmental Engineering at Stanford University.
Carol Kwiatkowski is a scientist at the Green Science Policy Institute.
They are the authors of the recent study, “Evaluating the Performance of Per- and Polyfluoroalkyl Substance Finishes on Upholstery Fabrics.”