Top is recessed to allow stacking. Jars of 125mL and 250mL sizes have standard mason jar threads. Ideal for museum jars — formaldehyde loss only about 2% per year. Remove closure before autoclaving, or set closure on top of jar at an angle without engaging the threads.
Suitable for food and beverage use. Meets requirements of CFR21, Part 177.1520 section of Food Additives Amendment of Federal Food and Drug Act.
Polypropylene white screw closures are linerless, noncontaminating, and autoclavable.