INDICATING PACKAGE

摘要

A package of oxygen sensitive product (10) has a body (5) a lid (15). The lid (15) includes a membrane (17), which incorporates ink (16), adapted to react to the presence or absence of a particular gas or mixture of gases in the headspace (25) of the package. The ink (16) is protected from the external environment by a barrier material (50, 51, 52), but is in fluid communication with the headspace (25). The barrier material (50, 51, 52) is chosen such that a user of the package may detect the reaction of the ink (16) through the barrier material.