Pressure sensitive closure pouch with insertable sterilization indicator

In a sterilization pouch comprising first and second opposing webs which are sealed together except for a region defining an open mouth and comprising sealing means for closing the mouth of said pouch and including a strip of adhesive on at least one of said webs adjacent to said open mouth, the improvement comprising:

• a peelable release strip superposed upon said adhesive strip, said release strip having an outer and an inner surface with said inner surface arranged in face-to-face contact with said adhesive strip and adhering thereto for masking said adhesive strip from external contact before said pouch is closed and sealed, said release strip including an indicator substance for indicating exposure to a predetermined sterilization condition, said indicator substance being present at least at said release strip inner surface and masked by an overlying thickness of said release strip and by said release strip outer surface, said indicator substance having an initial appearance color signifying that the indicator substance has not been subjected to said predetermined sterilization condition and said indicator substance further being adapted to change to a final appearance color upon exposure to said predetermined sterilization condition for indicating such exposure, said release strip being easily peelable from said adhesive strip whereby, when said release strip is removed from said adhesive strip and placed in said pouch and when said pouch is sealed and sterilized, said indicator substance changes from said initial appearance color to said final appearance color to indicate the attainment of said predetermined sterilization condition within said pouch.