Design teams want their buildings to look their best and to continue looking that way for years to come. So they choose materials that are durable and resist dirt, stains, and weathering. And that synthetic, shiny surface that sheds dirt doesn’t have to be replaced as often, saving energy, time, and resources. Sounds like a great low-carbon sustainability story. It also sounds a little unnatural … a little too good to be true. Maybe that’s because it is.
For the past half century, many of our colorful, shiny, dirt-, oil-, and stain-shedding materials have contained per- and polyfluoroalkyl substances (PFAS). We now know that many of these “forever chemicals” are persistent in the environment and have a number of potential negative health and environmental impacts.
PFAS can be found in gases, liquids, and as solid polymers. They are used in everything from food wrappers to high-temperature industrial systems. In our buildings, they have been used in carpet and textile stain treatments, coatings, sealants, other building products, and even refrigerants. Some of these products have been discontinued or are being reformulated to be PFAS-free, but the extensive and continued use of PFAS in building products, consumer industrial goods, and other applications over the past half century means that traces of PFAS have spread throughout the environment and are now found on every continent.
All of us would likely test positive for PFAS in our blood. They are one of the biggest health and environmental challenges ever faced by consumers and the building industry. But what exactly are PFAS, why are they such a problem, how can we avoid them in materials and products, and what are the tradeoffs for doing so?