Gas sterilization process challenge device

A sterilization challenge device for verifying an efficacy of a gas sterilization process, comprising:

• an outer container including an outer container wall, an outer container open end, an outer container closed end, an outer container chamber defined therein, and at least one outer container hole defined through a thickness of the outer container wall proximate the outer container open end, the outer container having an external thread proximate the open end;
• an inner container including an inner container wall, an inner container open end, an inner container closed end, and an inner container chamber defined therein;
• a chemical indicator arranged in the inner container chamber;
• and
• a cap configured to engage with the outer container to close the outer container open end, the cap including an internal thread arranged along an inner surface of the outer wall and configured to engage the outer container external thread,
• wherein the outer chamber is configured to contain the inner container and the chemical indicator arranged therein, wherein the at least one outer container hole is configured to provide a flow path for a gaseous sterilant into the outer container chamber,
• wherein the at least one outer container hole is disposed between the thread and the open end, and
• wherein the inner container includes an inner container hole defined through a thickness of the inner container wall, and the cap includes a sealing member, wherein the sterilization challenge device is configured such that the inner container open end is covered by the sealing member and pressed against the sealing member when the outer container is engaged with the cap.