A biological sterilization indicator for evaluating the effectiveness of a sterilization process includes a cap containing a culture medium, a container containing a concentration of microorganism, and a breakable barrier attached to the cap to encapsulate the culture medium therein. The breakable barrier is formed from a multilayer structure including an aluminum layer and a sealing layer. The biological indicator is configured such that the breakable barrier may be broken at a selected time by engaging the cap and the container at an activated position to introduce the culture medium into the container.
