7-PPD-Q is an oxidized derivative of the tire antiozonant and a substituted p-phenylenediamine 7-PPD.[1] 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.[2]
References:
[1].Wang, W., Chen, Y., Fang, J., et al.Toxicity of substituted p-phenylenediamine antioxidants and their derived novel quinones on aquatic bacterium: Acute effects and mechanistic insightsJ. Hazard. Mater.469:133900(2024).
[2].Wang, W., Cao, G., Zhang, J., et al.Beyond substituted p-phenylenediamine antioxidants: Prevalence of their quinone derivatives in PM[2].5Environ. Sci. Technol.56(15)10629-10637(2022).