Moving Past PFAS—Other Technologies in Use
As our testing shows, PFAS are a common way for companies to achieve water and stain resistance on garments and home furnishings, but alternatives to PFAS are also in wide use.
Water-Repellent Membranes And Finishes
As described earlier, waterproofing is typically achieved using a microporous membrane, a water-repellent finish, or both. While PFAS-based membranes and PFAS-containing finishes are now in common use, PFAS-free waterproofing has a long history and is also widely available. Back in the 1930s, tightly woven cotton fabric, forming a microporous structure, was developed for use by the British Air Force. Today, polyurethane is commonly used to create a microporous membrane, such as in Marmot’s MemBrain laminated fabrics and Jack Wolfskin’s Texapore. Sympatex® manufactures a membrane using polyester for use in apparel. To our knowledge, these alternatives have not been independently assessed for hazard.
Several kinds of PFAS-free water-repellent finishes are in common use. These include hydrocarbons, silicone, melamine, and highly branched molecules called dendrimers. Hydrocarbons and waxes are available and have increasingly been adopted by outdoor brands. Schoeller’s ecorepel® is a paraffin wax treatment used by Mammut, and Green Theme Technologies manufactures a hydrocarbon-based treatment, known as Empel™, now used by Black Diamond. Rudolf Group’s Bionic Finish® Eco, used by companies including H&M, is an example of a dendrimer-based treatment. Melamine is used in conjunction with stearic acid, reacted with formaldehyde, as a surface treatment. Melamine compounds were recently detected in a high proportion of infant clothing items tested with the highest levels in outerwear. Silicone treatments have been introduced by major companies such as Dow.
While the composition of these treatments is generally guarded by producers as proprietary, researchers conducted a general hazard assessment of durable water repellents that included PFAS, hydrocarbons, and silicone. This assessment scored paraffin wax, representing hydrocarbon treatments, as GreenScreen Benchmark 3, or recommended for use. In contrast, the assessment of chemicals likely found in silicone-based treatments identified hazards including repeated-dose toxicity, aquatic toxicity, persistence, and bioaccumulation.
Many companies successfully produce products that are easily cleanable without the use of PFAS-containing surface treatments. For home furnishings such as tablecloths and napkins, this may be as simple as machine washability. For larger items such as furniture and carpet, this may involve the use of more specialized cleaners, which can be selected from items designated safer under the USEPA’s Safer Choice program.