October 06, 2015
Image of Sulfoxaflor 3D Image of Sulfoxaflor

Sulfoxaflor is a pesticide that kills insects by attacking their central nervous system. It is a member of the sulfoximine family of insecticides. In 2013, the US Environmental Protection Agency (EPA) approved this Dow AgroSciences product for use in the United States. It is also registered in some Central American and east Asian countries.

The EPA registered sulfoxaflor despite its potential toxicity to honeybees. It recommended that the insecticide not be used when flowering crops are attracting bees.

A consortium of beekeeping trade groups sued the EPA shortly after registration, believing that sulfoxaflor would exacerbate the declining bee population. In September 2015, a federal appeals court overturned the registration by ruling that the supporting studies were insufficient to demonstrate that sulfoxaflor does not cause environmental harm. Dow says it will perform additional studies and may appeal the court’s decision.

MOTW update: July 22, 2019

Sulfoxaflor is a central nervous system insecticide that is toxic to honeybees. In 2015, a federal appeals court overturned its US Environmental Protection Agency registration. But earlier this month, in a controversial move, EPA reauthorized its use on several crops. Will more legal action follow?

MOTW update: January 16, 2023

Sulfoxaflor1 is an insecticide that the US Environmental Protection Agency approved for use in 2013. In 2015, EPA banned its use because of its toxicity to honeybees; but, controversially, in 2019, under the Trump administration, the agency reauthorized its use on several crops. This past December, the US Court of Appeals for the 9th Circuit ruled that the EPA broke the law by reauthorizing sulfoxaflor because it failed to assess endangered species risks and did not give the public a chance to comment on its decision.

1. CAS Reg. No. 946578-00-3.

MOTW update: November 12, 2015

The October 5, 2015, MOTW noted that a federal appeals court had overturned the registration of the insecticide sulfoxaflor because of its toxicity to honeybees. As a result of this court order, on November 12, 2015, the US Environmental Protection Agency stopped the sale of this chemical in the United States. The manufacturer, Dow AgroSciences, intends to work with EPA to return sulfoxaflor to the market.

Chemical Abstract Service - a division of ACS

Learn more about this molecule from CAS, the most authoritative and comprehensive source for chemical information.

Molecule of the Week needs your suggestions!

If your favorite molecule is not in our archive, please send us a message. The molecule can be notable for its current or historical importance or for any quirky reason. Thank you!

Stay Ahead of the Chemistry Curve

Learn how ACS can help you stay ahead in the world of chemistry.