What does OEKO-TEX STANDARD 100 mean on a liner?

It's a certification indicating the textile or material has been tested for certain harmful substances. Several picks here (LiBa, Barossa, ALYVIA SPRING, N&Y HOME, NTBAY) carry the claim, which matters to buyers worried about chemical smell from new plastic liners, though it is a manufacturer-supplied certification rather than an independent test result we could verify.