According to Appendix VI of Regulation (EC) No 1272/2008 (CLP Regulation), the salts and esters of MCPA (ISO) are to be classified at least as Acute Tox. 4 (H332, H312, H302). If the user has data according to which the substance is to be classified as Acute Tox. 3 or higher, the substance must be assigned to an appropriate collective entry of Class 6.1. In addition, it must then be marked as "environmentally hazardous".