Sterilisable packets with chromatic treatment indicators - between laminated plastics films, to prevent contamination of misleading exposure variations

摘要

Bags or envelopes for items requiring sterilisation have at least one face made of laminated film between the layers of which is included one or more patches of reagent which will change colour when subjected to the sterilisation treatment. Used esp. for packaging surgical instruments etc. to be subjected to chemical sterilisation by treatment with e.g. ethylene oxide. Entrapment of the indicator reagents between layers of film chosen to be impermeable to the reagents but not to the sterilising medium (gas; heat; steam; radiation) prevents possible contamination by the reagents of the pack contents or of those who handle the pack. Pref. the reagents are enclosed between a layer of poly-propylene film and a layer of polyester film, the polypropylene being the closer to the pack contents. The other face of the envelope may be of paper or other material relatively permeable to the sterilising reagent, which has also to permeate the polypropylene layer to reach the indicator reagents, thus ensuring that the pack contents must receive at least as much exposure to the sterilising agents as the indicators.