Review of Bee Health

EPA’s review of the European Food Safety Authority’s conclusions regarding studies involving the neonicotinoid pesticides

For Release: December 20, 2013

On request from the European Commission, the European Food Safety Authority (EFSA) asked its Panel on Plant Protection Products to develop a scientific opinion on the potential for harmful developmental effects on the nervous system (developmental neurotoxicity) of the neonicotinoid insecticides.

This request was based, in part, on a recently published study by Kimura-Kuroda et al. (2012) that used cells to assess potential developmental neurotoxicity of this class of insecticides. The EFSA panel concluded that this study is not appropriate to use to make regulatory decisions, and EPA agrees with that conclusion.  EFSA’s Panel was also asked to review the potential for developmental neurotoxicity because, in Europe, toxicity studies specifically designed to provide data to evaluate this potential risk are not typically required. EPA began requiring developmental neurotoxicity studies for active ingredients meeting certain criteria in 1999.

EFSA Panel’s review and recommendations

The EFSA Panel reviewed information available to European regulatory agencies and EPA concerning two neonicotinoid insecticides – acetamiprid (ACE) and imidacloprid (IMI). For ACE, European agencies did not require developmental neurotoxicity test (DNT) studies, so the Panel reviewed data summaries from the study submitted to EPA in 2003.  In the case of IMI, a DNT study was submitted to EPA in 2001 and a separate study was submitted to the European authorities.

While EPA concluded that the DNT studies for ACE and IMI were reasonably executed and provided information that was acceptable for use in our risk assessments, the EFSA Panel concluded that all three studies, to varying degrees, may have underestimated potential effects, and it was not possible to draw firm conclusions on the doses that cause no effects.  For that reason, the Panel recommended alternative interpretations of the study results that could be used in updated European risk assessments.  The Panel also recommended that new studies be undertaken with an alternative, but similar, DNT test protocol to determine if more sensitive responses could be detected.  Finally, the Panel recommended that EFSA establish a process to determine when to request developmental neurotoxicity studies.

EPA’s review of the Panel’s conclusionsAlthough EPA has only had a short time to review the Panel’s report on the toxicity of ACE and IMI, our initial evaluation does not warrant any change to our current risk assessment conclusions.  Moreover, revisions to incorporate EFSA’s recommendations would not impact the agency’s current regulatory positions on these chemicals.  We maintain that both pesticides are safe for humans when used according to the EPA-approved label. We will continue to review the Panel’s report.

EPA’s Registration Review of the neonicotinoidsThe registration review process allows EPA to act quickly if the data and associated scientific evaluations warrant such action. If the risk posed by a pesticide, supported by the best available, peer-reviewed science, cannot be mitigated or managed through other measures, and the agency determines that the pesticide no longer meets the Federal Insecticide, Fungicide and Rodenticide Act standard for registration, then the agency will move quickly to take appropriate regulatory action.  The neonicotinoid pesticides are currently undergoing registration review and EPA is scheduled to conclude this evaluation in 2018.  The registration review schedule for the neonicotinoids is available at http://www.epa.gov/opp00001/ecosystem/pollinator/risk-mgmt.html