Welcome to Law.com Class Actions: Critical Mass, a weekly briefing for class action and mass tort attorneys.

This week: 3M is close to settling thousands of lawsuits over “forever chemicals” in aqueous film-forming foam, used by firefighters, for potentially $10 billion. As a rare trial begins over Johnson & Johnson’s baby powder, a controversial plaintiffs’ expert in talc cases remains a target. Find out who represents Nike in a class action over the labeling of its “sustainable” clothing line.