Instant, self-sealing sterilization pouches eliminate the need for heat sealing and separate sealing tapes. Protective strip removes from fold-over adhesive end to provide complete hermetic seal. Seal will not open up in steam autoclaves and is unaffected by gas. Pouches are tamper-proof, producing visible evidence of seal tampering, and have the same sterile storage time as all pouches. Penetration of sterilants into pack is monitored by preprinted indicators on both inside and outside for steam and EO gas. In steam, yellow indicators change to gray-black; red indicators do not change. In gas, red indicators change to green; yellow indicators do not change.