Patent ID: 7090808

Claim:
An apparatus for testing one or more sterilization indicators by contacting them under controlled sterilization conditions with a flowing antimicrobial gas comprising hydrogen peroxide vapor, the apparatus comprising: (a) antimicrobial gas generating means for providing the flowing antimicrobial gas comprising hydrogen peroxide vapor, the antimicrobial gas generating means comprising: (1) a vaporization plenum having an inner surface; (2) means for breaking a vaporizable liquid comprising hydrogen peroxide into fine particles and for flowing the fine particles in the vaporization plenum, the bulk flow of the fine particles flowing in the vaporization plenum being in a first direction; (3) means for flowing a gas or vapor comprising a first substance in the vaporization plenum and for flowing at least some of the first substance between the inner surface of the vaporization plenum and substantially all of the fine particles to create a curtain of first substance between the inner surface of the vaporization plenum and substantially all of the fine particles, the bulk flow of the first substance in the vaporization plenum flowing in substantially the same direction as the first direction; and (4) means for causing substantially all of the fine particles to vaporize in the flow of the first substance to produce a substantially continuous flow of a gas-phase mixture of the first substance and vaporized hydrogen peroxide of substantially constant hydrogen peroxide concentration as a function of time, the antimicrobial gas comprising the gas-phase mixture; (b) a chamber in which the one or more sterilization indicators can be contacted with the flowing antimicrobial gas; (c) means for rapidly placing the one or more sterilization indicators in the chamber while the flow of the antimicrobial gas in the chamber is substantially continuous and the concentration of hydrogen peroxide in the antimicrobial gas is substantially constant as a function of time; (d) means for continuing to flow the antimicrobial gas in the chamber to contact the one or more sterilization indicators from substantially the moment they are placed in the chamber, the contact being under substantially uniform conditions for the desired contact time, the flow of the antimicrobial gas during the contact being substantially continuous and the concentration of hydrogen peroxide in the antimicrobial gas during the contact being substantially constant as a function of time; and (e) means for rapidly removing the one or more sterilization indicators from the chamber after the desired contact time of the one or more sterilization indicators with the antimicrobial gas has elapsed.