2021 U.S. Scrap TIre Workgroup (USSTWG)

University of Nevada, Reno research on rubberized asphalt and 6PPD/6PPD-quinone • Data gap – Is rubber modified asphalt a source of 6ppd and 6ppd-quinone in the environment? • Research to fill gap – “An on -going study at the University of Nevada, Reno (UNR) has been evaluating the release of 6PPD and 6PPD-quinone from rubberized asphalt mixtures and the impact of rainfall condition and asphalt mixture composition. Based on a synthesized standard of 6PPD-quinone (Agua et al., 2021), a test showed that commercially used rubberized asphalt mixture released 0.009 microgram/L 6PPD-quinone to the solution phase (in a controlled laboratory experiment), when 10 g/L of rubberized asphalt mix in DI water was shaken for 12 days (Lokesh unpublished data). Furthermore, 6PPD-quinone was below 1 nanogram/L (<0.001 microgram/L) using solid phase extraction-HPLC- UV analysis for the runoff water collected from a rainfall simulation (1 mL/min for a duration of 16 hour) with the same rubberized asphalt mixture. The data is under validation with analysis using HPLC- Triple Quadrupole Mass Spectrometry.” • References: Agua A, Stanton R, Pirrung M. Preparation of 2-((4-Methylpentan-2-Yl)amino)-5-(Phenylamino)cyclohexa-2,5- Diene-1,4-Dione (6PPD-Quinone), an Environmental Hazard for Salmon. ChemRxiv. Cambridge: Cambridge Open Engage; 2021; This content is a preprint and has not been peer-reviewed. Lokesh S, Arunthavabalan S, Hajj E. Y., Yang Y. Release of 6PPD-quinone from rubberized asphalt. Unpublished. 8