Guidance on Light-Dependent Peroxidizing Herbicides: Use of the Molar Threshold Value for Adjusting Fish Chronic Endpoints to Account for Ultraviolet Light-enhanced Toxicity
EPA has developed the following guidance for light-dependent peroxidizing herbicides (LDPHs) and other chemicals that may act via a light dependent peroxidizing (LDP) mode of action.
The purpose of this guidance is to assist risk assessors in: (1) identifying herbicides and other pesticides that may act through a LDP mode of action; and (2) applying a molar threshold to fish chronic toxicity test endpoints in the absence of chemical-specific data to account for ultraviolet (uV) light-enhanced toxicity.