Patent ID: 7674440

Claim:
An enclosure for carrying out an operation under sterile conditions, the enclosure comprising: a main chamber; a first apparatus disposed within the main chamber for generating and delivering a sterilant vapour from a supply held within the main chamber to be distributed throughout the main chamber to sterilise the surfaces of the main chamber; a plenum chamber; a filter separating the plenum chamber from the main chamber; a pump for the plenum chamber for delivering air into the plenum chamber and then through the filter to the main chamber to create a filtered flow of air through the main chamber; and means for drawing gas from the enclosure via an outlet from the plenum chamber to create a flow of sterilant vapour from the main chamber through the filter to decontaminate the filter and through the plenum chamber to the outlet to sterilise the plenum chamber before exiting the outlet and to maintain pressure in the main and plenum chambers below atmospheric so that any leak paths result in leakage from the atmosphere into the chambers and do not result in release of sterilant vapour to the atmosphere around the enclosure; wherein the flow of air into the main chamber and the flow of sterilant vapour out of the main chamber pass through the same filter; wherein the means for drawing gas from the enclosure comprises a fan located in a conduit connected to the outlet; and wherein the conduit has means for rendering sterilant flowing through the conduit ineffective to avoid release of sterilant to atmosphere.