Students attend the first day of school at Howard Elementary School in Oakland in 2021. A class of chemicals known to be harmful is found in many of the textiles in children's clothing, especially items that are stain-resistant or water-repellent.

Most parents take extra precautions to protect their children from toxic chemicals — from locking cabinets of cleaning supplies to scrutinizing ingredient labels. But some toxic chemicals are near impossible to limit their exposure to.

Perfluoroalkyl and polyfluoroalkyl substances, known as PFAS, are a class of over 9,000 industrial compounds that are added to everyday products to repel stains, water or oil. They might be in your favorite rain jacket, the nonstick pan you flip pancakes in or your waterproof mascara. Commonly referred to as “forever chemicals,” they do not break down in the environment — ever. And eventually, they end up in our food and drinking water. According to the nonprofit Environmental Working Group, these chemicals may be contaminating the drinking water of up to 200 million Americans. But because of their ubiquity in products and the environment, most of us inadvertently drink, eat, absorb and breathe them every day.

Given that there are thousands of these substances, this class of chemicals is not easy to study. But the research that has been done so far is concerning. These chemicals have been associated with myriad health harms, including cancer, obesity, developmental delays and reduced vaccine response in children. They’ve also recently been linked to more severe COVID-19 outcomes. Additionally, some of these chemicals first claimed to be safe were determined later to be harmful to our health, which is why leading scientists agree that the thousands of PFAS on the market should be regulated as a class rather than one by one.

For families with kids, figuring out how to limit their children’s exposure to this class of chemicals is a daunting task. Fortunately, California lawmakers are moving to add protections against the substances in one industry that would have a significant impact on all Californians and most importantly, our kids: textiles.

AB1817, which passed the state Legislature, would ban the manufacturing, distributing and selling of any new textile in California that contains regulated PFAS by 2025. Why textiles? Because it’s an industry whose products are in near constant contact with our skin — and many of those products contain the substances.

In a 2022 report from the nonprofit Toxic-Free Future, researchers tested 60 products for PFAS from 10 major retailers, including Walmart, Target and REI. Products tested included a range of types, many within the textile category — from outdoor apparel to napkins to bedding. Of the 47 products marketed as stain or water repellant, 72% contained the substances. When narrowing the focus to children, the findings are even more concerning.

In a newly published study in the journal Environmental Science & Technology, researchers from Indiana University, Notre Dame, the University of Toronto and our organization, the Green Science Policy Institute, analyzed 72 children’s textile products marketed as stain resistant, with an emphasis on school uniforms. Overall, our study found PFAS in 65% of the items tested. But among the school uniform items, which came from nine popular brands used in public, private and parochial schools across the country, the substances were present in all of them. Based on discussions with manufacturers, we believe that any uniform labeled “stain resistant” will very likely contain PFAS, regardless of brand. This presence in uniforms is particularly concerning as they are worn directly on the skin for up to eight hours a day by a quarter of children in the U.S.

AB1817 is awaiting final approval from Gov. Gavin Newsom. If made into law, not only will it end one of the major pathways for human exposure to PFAS in California, it will also lower the level of exposure from textiles around the country — as manufacturers adjust their manufacturing processes to comply with our state’s laws.

Codifying AB1817 into law will assert California’s leadership in solving the nation’s PFAS crisis. Although currently, there is rightfully a lot of focus on cleanup and remediation, none of that progress will matter if the supply chain continues to feed products with the substances into the market. AB1817 ensures that at least in one critical industry that is a continuous source of harmful chemicals is stopped.

While California awaits Newsom’s signature, parents can do their best to limit exposure to their kids by avoiding products advertised as “stain resistant” or “waterproof.” For already-purchased clothing and other textile products, multiple washes should reduce exposure.

Most importantly, parents can let their government leaders and favorite brands know that they value their children’s health far more than they hate stains.

Rebecca Fuoco is the science communications officer at the Green Science Policy Institute. Arlene Blum is the founder and executive director of the Green Science Policy Institute and a research associate in the Cell and Molecular Biology Department at UC Berkeley.