An environmental group that has a growing beef with 3M about its sustainability practices picked the All-Star Game on Tuesday to lodge its latest grievance against the company.

California-based Forest­Ethics hired an aviation firm to fly an airplane over Target Field and downtown Minneapolis with a banner that read "3M do the right thing for forests" as part of a protest against 3M's supply relationships with companies that allegedly harm forests.

ForestEthics spokesman Jim Ace told the Star Tribune that 3M buys its paper pulp and other paper products from logging companies that strip forests in the United States, Canada, Brazil and Indonesia. The group also complained that 3M uses the Sustainable Forest Initiative (SFI) certification, which Ace said is weak because it is backed by a logging association made up of companies that hurt forests.

"What we want 3M to do is to adopt policies that make sure that its supply chain is free of products from endangered or controversial forests," Ace said.

ForestEthics has asked Maplewood-based 3M to stop using the SFI certification and to revamp its paper purchasing policies. The two groups used to work together until talks broke off late last year.

3M spokeswoman Sarah Williams said she sees the two entities collaborating again.

"We absolutely do support forestry certification, but we also have a fundamental difference of opinion from ForestEthics," Williams said. "They believe in one certification and we, like others, believe that there are other certifications that are equally as valid. We use several."

ForestEthics flew the banner over Target Field between 3:30 and 5:30 Tuesday afternoon. FAA regulations required the plane to be at least three miles away by 6 p.m., so it was not clear how many baseball fans saw the banner.

Despite ForestEthics' protest, Williams said she expects the two groups to work together again. "Business has a responsibility to operate in a sustainable manner and that includes responsible forestry. And I know that is a deep interest of ForestEthics."

It's the latest high-profile finger-wag from ForestEthics, a group that recently held protests in front of 3M's annual meeting in Texas in costume to protest 3M's paper sourcing choices for the Post-it notes and sandpaper it makes.

Dee DePass • 612-673-7725