By derogation from subsection 3.2.3.1, Column (16) and Chapter 9.3 of the Regulations annexed to ADN, tank vessels, whose substance list includes substances assigned to explosion group römisch zwei B but which are equipped with flame arresters for explosion group römisch zwei B3, may continue to be equipped with flame arresters for explosion group römisch zwei B3 for the carriage of those dangerous goods of their substance list that are assigned to explosion group römisch zwei B, until the renewal of the Certificate of Approval after 31 December 2018.