It’s everywhere, taking over like the weeds it’s meant to kill. Now glyphosate, the bestselling weedbuster of all time, has become a pest.

“Everybody in this room has glyphosate and other components in Roundup in their body,” said Dave Schubert, a researcher at Salk Institute who spoke in favor of a ban last week that supervisors have proposed for the unincorporated county.

Around the country, tens of thousands of lawsuits target glyphosate-based herbicides which homeowners, groundskeepers and others say caused their cancer. Heavy use of the chemical in agriculture has promoted superweeds, and is suspected of harming pollinators like honeybees.