Portland banned the use of neonicotinoid insecticides, a wide-ranging classification of chemical pest killers, on city-owned property.

The City Council unanimously approved an emergency ordinance Wednesday, making the insecticide ban effective immediately.

"We're doing another good thing for the people of Portland, Oregon, the United States, maybe the entire world," said Commissioner Amanda Fritz, who introduced the policy.

Few question the efficacy of the insecticides, which have a long shelf life and quickly kill pests. But the chemical sprays persist in the environment, and opponents say they provide a clear and documented harm to bees, birds and butterflies.

Studies indicate the insecticides may be a factor in massive die-offs of bee colonies. In Oregon, state officials blamed the 2013 deaths of tens of thousands of bees on the improper use of the pesticides. Last month state officials banned the products from use on certain trees.

Fritz thanked her staff and parks officials for their work on the ordinance, but lauded the advocacy work of the Xerces Society, Audubon Society of Portland, Center for Biological Diversity and Beyond Toxics group for pushing the idea.

"These toxicants kill bees outright, so this ordinance is critical to protecting Portland's burgeoning local foods movement," Lisa Arkin, executive director of Beyond Toxics, said in a press release.

The ban does not apply to private property, although Fritz said last week the proposal was just a first step.

Lori Ann Burd, environmental health director at the Center for Biological Diversity said the ban would benefit the entire ecosystem. "Neonicotinoids kill the beneficial insects that form the basis of the web of life, like caddisflies and mayflies, which are important food sources for salmon and trout," she said.

Portland's ordinance also urges retailers to label insecticides products or other items that may contain the neonicotinoid chemicals.

The ordinance doesn't immediately apply to two rose gardens where the city will run a "pilot program" to find an alternated insecticide or method to kill-off rose midges, a pest that is more difficult to kill without the insecticides. The city must identify alternative methods by December 2017.

Portland's ban follows similar actions in Spokane, Seattle and Eugene. The U.S. Fish and Wildlife Service also pledged to ban the insecticides last year on more than 150 million acres of public land.

-- Andrew Theen

503-294-4026

@cityhallwatch