Green group sues EPA over new weed killer approval

The Natural Resources Defense Council (NRDC) has sued federal regulators to reverse the approval of a powerful new pesticide.

The NRDC said Dow Chemical Co.’s Enlist Duo weed killer would destroy monarch butterfly populations and pose a risk to human health.

The Environmental Protection Agency (EPA) approved the herbicide for use with genetically modified corn and soybeans — also sold by Dow — earlier Wednesday for six states.

“This weed killer is more bad news for monarch butterflies, whose migrating population has dropped by more than 90 percent in recent years because glyphosate has wiped out the milkweed they need to survive,” Sylvia Fallon, a senior scientist at the NRDC, said in a statement.

Glyphosate, sold under the brand name Roundup, is one of the ingredients in Enlist Duo, along with 2,4-D, another existing herbicide.

“EPA completely ignored the impact on monarchs when it granted this new approval, and seriously underestimated the toxicity for people,” Fallon said.

The NRDC filed its lawsuit Wednesday in the Court of Appeals for the District of Columbia Circuit.

The group was not alone among green groups in sharply criticizing the EPA’s decision.

Earthjustice accused the agency of ignoring potential harm to humans and wildlife from the herbicide, and said it would evaluate legal options to challenge the decision.

The Organic Consumers Association and Just Label It said they were disappointed.

For its part, the EPA said it thoroughly studied possible harms to all age groups, wildlife, the environment and agricultural workers, among other factors, before granting approval. Enlist Duo passed all the tests, it said.

Dow said it plans to start selling the product next year.