What Are PFAS in School Bags? The Forever Chemicals Explained By Chester Takau · July 2026 Short answer: PFAS ("forever chemicals") are the family of fluorinated compounds used to make school bags water- and stain-resistant, usually applied as a durable water repellent (DWR) coating on the outer fabric or zipper tape. A 2023 lab test of 19 kids' backpacks found 68% carried a detectable PFAS marker. The main exposure risk isn't touching a finished bag day to day — it's manufacturing and disposal — but 2026 has brought a run of new research linking early-life PFAS exposure to intestinal inflammation, lower bone density, and possibly childhood leukemia, which is why states are moving to restrict them in kids' products faster than ever. What exactly are PFAS, and why would they be in a backpack? PFAS stands for per- and polyfluoroalkyl substances — a family of thousands of manufactured chemicals built around a carbon-fluorine bond so strong it barely...