Notes: 7-PPD-Q is an oxidized derivative of the tire antiozonant and a substituted p-phenylenediamine 7-PPD.{72316} It is toxic to the bacterium V. fischeri (EC50 = 14.9 mg/L). It has been found in fine particulate matter 2.5 (PM2.5) samples collected at the roadside in China.{72313}