Mixtures Equation Pilot Program to Reduce Animal Use in US EPA Pesticide Testing

On December 20, 2016 the US EPA Office of Pesticide Programs (OPP) announced the start of a voluntary pilot program to evaluate the use of a mathematical tool in predicting the acute toxicity of pesticide formulations. Known as the Globally Harmonized System (GHS) Mixtures Equation, this tool can be used as an alternative to new animal testing. For the pilot program, OPP is asking pesticide companies to submit acute oral and acute inhalation toxicity study data paired with calculations derived from the GHS Mixtures Equation in order to evaluate the equation’s ability to predict end product oral and inhalation toxicity.

Under current OPP data requirements, companies seeking to register new pesticide end products must perform acute oral and inhalation toxicity studies on animals to determine hazard classification and package labeling even though toxicities for the individual ingredients are likely already known. By using the GHS Mixtures Equation, end product toxicity can be estimated by “adding” together the individual ingredient toxicities without conducting new animal tests. OPP anticipates that the pilot will run for approximately six months; however, it will begin its analysis earlier if sufficient data are received before this time. The submissions will be used to evaluate the performance of the mixtures equation as an alternative to oral and inhalation toxicity studies for pesticide formulations. Registrants may submit data as part of an incoming application for product registration/amendment or may submit existing data not related to a current registration action.

Since OPP receives 200-300 applications for new formulations annually, applying the equation could save 5,000 or more animals each year, in addition to saving companies considerable time and money on future registrations. Instructions on performing the calculation and where to submit data are given on a US EPA webpage devoted to the pilot.