LowEmissionAsphalt-136pg-WhitePaper-May2023

P a g e | 99 Forever Chemicals A lso found in tire-wear debris are these so- called “forever chemicals.” Present in many household products are these highly toxic fluorinated chemicals categorized generally in the family of perfluoroalkyl and polyfluoroalkyl substances often referred to as “PFAS” . They end up in our air and water and build-up in wildlife and human organs. They never naturally break down in the environment. PFAS is linked to reproductive problems, auto immune deficiency diseases, and various forms of cancer. No product containing PFAS or a PFAS precursor releases more of this in the environment than on-road tire wear. 214 In tires, a processed chemical known as 6PPD 215 is universally used as a preservative film or buffer against oxidation. It is very effective at improving tire life as it aggressively interacts with ground-level ozone, thus protecting the tires. But when this film additive itself oxidizes, it transforms into the PFAS 6PPD-quinone or 6PPD-Q. 216 6PPD-Q is similar to a polycyclic aromatic hydrocarbon (PAH). 6PPD-Q is water soluble, so it is easily transferred from the road as stormwater into sewers, creeks, and rivers, and similar to MPPs, end-up in large bodies of water where they are very harmful to ecology and wildlife. 6PPD-Q is lethal to various aquatic species at concentrations as low as 0.5 ug/L or the equivalent of 0.5 parts per billion. 217 218 With regulations on the horizon, particularly in communities near major estuaries, rivers and direct access to lakes and the ocean, agency stormwater managers will be looking for answers for certain types of PFAS contaminations emanating from roadways. 214 EPA; Centers for Disease Control and Prevention (CDC); Michigan Department of the Environment; U.S. EPA Great Lakes National Program Office; Washington State University; Great Lakes Now , January 2022. 215 N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine. 216 CAS# 2754428-18-5. 217 Brinkmann M, et al., Acute Toxicity of the Tire Rubber-Derived Chemical 6PPD-quinone to Four Fishes of Commercial, Cultural, and Ecological Importance, Environmental Science & Technology Letters , March 2022. 218 EPA: Archives of Environmental Contamination and Toxicity - Johannessen C, et al., The Tire Wear Compounds 6PPD-Quinone and 1,3-Diphenyguanidine in Urban Watershed, August 2021. When a tire additive known as 6PPD and ozone mix, major stormwater runoff concerns emerge.