Notes: 77PD-Q is a p-phenylenediamine quinone (PPD-Q) and an oxidized derivative of the antiozonant 77PD.{72316} It is toxic to the aquatic bacterium V. fischeri (EC50 = 13.6 mg/L). It has been found in fine particulate matter 2.5 (PM2.5) samples collected at the roadside in China.{72313}