Polypropylene caps are autoclavable unless they have a non-autoclavable lining. Black Phenolic Cap with 14B White Rubber Liners are autoclavable. The rubber liner is compliant with FDA 21 CFR 177.2600 Rubber Articles Intended for Repeated Use. Unlined polypropylene caps can also be autoclaved, as can polypropylene hole caps (without their septa).
