EPA Approved Pesticide that Harmed Honeybees

Published Feb 2, 2015

What happened: The EPA approved the insecticide sulfoxaflor despite insufficient data documenting its environmental safety and ignoring the EPA’s own ecological assessment that showed that it is harmful to bee populations.

Why it matters: By failing to obtain sufficient ecological data and ignoring the agency’s assessment of the pesticide’s high toxicity to bees, the EPA approved a pesticide that was not based on the best available science and was out of step with the requirements in the Federal Insecticide Fungicide and Rodenticide Act.


In 2013, the EPA granted approval to the insecticide sulfoxaflor based on insufficient data submitted by Dow AgroSciences and also failed to fully consider the EPA’s ecological assessment showing that the pesticide is highly toxic to honey bee populations. The EPA’s study, known as the Honey Bee Risk Assessment, found that sulfoxaflor can induce high mortality in honey bee populations from zero to three days after application, with a morality rate that was on average as high as seven to twenty times that of controls. The pesticide was also observed to cause declines in flight intensity to bee populations. Sulfoxaflor has also been documented to cause harm to other organisms, including saltwater invertebrates, mammals, and birds.

According to a letter submitted to the EPA from eight environmental and public health non-profit organizations, there also appeared to be substantial data gaps on real-world scenarios in the industry data submitted to the EPA. In particular, there were data gaps on the effects of the pesticide on bee populations within the ranges of potential application; the industry studies examining these effects contained limitations and flaws in their methodologies.

In 2015, the US Court of Appeals for the Ninth Circuit came to the same conclusion, finding that the EPA relied on “flawed and limited data” to approve the unconditional registration of sulfoxaflor, and that approval was not supported by “substantial evidence.” The court also found that the EPA approved use of sulfoxaflor without restrictions, even though Dow failed to carry out the studies previously requested by the EPA to examine the effects of the pesticide on various species, including bees.

Under the Federal Insecticide Fungicide and Rodenticide Act, the EPA is charged with assessing new pesticide products for potential registration, but the applicant has to show that use of the pesticide “will not generally cause unreasonable adverse effects on the environment.” For sulfoxaflor, Dow AgroSciences failed to provide the EPA with sufficient evidence of the ecological effects and the EPA ignored its own assessment that showed serious adverse effects on honeybee populations. The approval of pesticides is contingent upon evidence that shows it does not cause substantial harm to the environment and, by approving use of sulfoxaflor, the EPA failed to incorporate the agency’s own analysis into decisionmaking that suggested potentially devastating harms on honeybees and other organisms.