Corks

Corks are commonly used in laboratories as a material to stop test tubes and flasks because of their impermeability and general absence of toxic elements. Cork, also known as a stopper or bung, is partially inserted inside a container to form a seal. Cork stoppers are generally safe for packaging or food processing and are best suited for solid specimens and materials. Corks should be rolled on a clean surface to soften their lower half before use, allowing the cork to expand and form a tight seal when pressed into a flask or vial. These products are available in many different sizes.