Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Not written by a barrister. The name was thought up by a second-year American law student sitting in a coffeehouse in Manhattan. Neither an authoritative statement of the law nor legal advice. Don't rely. Quick work.
Sixth Circuit: Anthony Smith, Jr. v. Joy Technologies, Inc.
Torts
Under state law, in products liability, there is no duty to warn where the danger is known.