The organophosphate insecticide tetrachlorvinphos (TCVP) used in pet products to control fleas and ticks may pose a health risk to small children, according to a draft assessment released by EPA late last month. Specifically, the potential risk is for toddlers aged one to two years who come into contact with pets treated with the chemical in dust form. EPA conducted the assessment in response to a lawsuit by the environmental group Natural Resources Defense Council, which wants the agency to ban all pet products containing TCVP. The group claims that the pesticide is neurotoxic and poses unacceptable risks to children’s developing brains and nervous systems. In 2014, EPA denied a petition from the group seeking a ban, saying TCVP pet products pose no risk to human health. NRDC then challenged that decision last year. As part of that litigation, EPA agreed to release a revised health risk assessment for the chemical by the end of 2016. The draft assessment considers new data about residue on pet fur and about liquid and dust formulations with TCVP.