Notes: CPPD-Q is a p-phenylenediamine quinone (PPD-Q) and an oxidized derivative of the antiozonant CPPD.{72316} It is toxic to the aquatic bacterium V. fischeri (EC50 = 6.98 mg/L). It induces intestinal production of reactive oxygen species (ROS) in C. elegans when used at concentrations of 1 or 10 µg/ml.{68731} CPPD-Q has been found in fine particulate matter 2.5 (PM2.5) samples collected at the roadside in China.{72313}