Toxicological and environmental issues associated with waterproofing and water repellent formulations

Safer ingredient selection as part of the design of durable water repellants and waterproofing agents in textiles and clothing continues to challenge formulators due to the unique attributes of these formulations. Over the past 15 years, reports of bioaccumulation and long environmental persistence of certain chemicals in water repellant and waterproofing formulations have shone an unkind spotlight on specific chemistries (notably, long-chain fluorochemicals such as PFOA and PFOS, as well as cyclic siloxanes such as D4 and D5). This chapter provides an overview of the primary toxicological and environmental issues associated with water repellants and waterproofing formulations, discusses initiatives intended to reduce and eliminate chemicals of concern in such formulations, and identifies sector-specific initiatives and assessment paradigms focused on the selection of safer and sustainable ingredients used in water repellants and waterproofing formulations. Among the five major classes of ingredients used in water repellents and waterproofing agents, a review of available data indicates that hydrocarbon-based polymers are the most environmentally benign, followed by siloxane-based, and short-chain PFAS-based polymers. While short-chain fluoropolymers may provide better water and stain repellency, their use may not be worth the perceived and actual human health and environmental risks. Better understanding of the existing and emerging alternatives can only be resolved with greater transparency and with publicly available and peer-reviewed hazard profiles.