The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated octylated diphenylamine [68411‐46‐1] to derive a maximum concentration at the workplace (MAK value), considering all toxicity endpoints. Available unpublished study reports and publications are described in detail. The critical effect of octylated diphenylamine is hepatotoxicity after repeated gavage administration to rats. Octylated diphenylamine is a UVCB‐substance, a substance of unknown or variable composition, complex reaction products or biological materials. A representative composition is not known. Thus, a MAK value could not be derived and the substance is classified in Section II b of the List of MAK and BAT Values. The substance is not genotoxic. Carcinogenicity studies and data on the potential of contact sensitization in humans are not available. The substance is not a contact sensitizer in guinea pigs. Skin contact is not expected to contribute significantly to systemic toxicity.