Bowie Dick test

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A possible test arrangement for the Bowie-Dick test (the test card is placed in a stack of tightly compressed absorbent paper)

The Bowie-Dick test is a procedure for testing the performance of medical steam sterilizers with a fractional prevacuum. It simulates the difficult steam penetration of a tightly pressed package of 7 kg of textiles. According to the EN 867-3 standard for packaged items to be sterilized and porous loads, such proof is required. It also serves as proof of conformity with the EN 285 standard and should be carried out as a routine test in accordance with EN 554 once a day to check the function of the fore-vacuum.

Indicators for checking the sterilization effect show by a color change whether the prescribed sterilization conditions prevailed in their environment, i.e. whether the sterilization was carried out successfully. Since the indicators are usually in the form of adhesive strips or markings on the packaging on the outside of the items to be sterilized, the complete penetration of cavities and porous material with steam, which is essential for the sterilization effect, is not recorded. In order to achieve this safely, in modern autoclaves the air is pumped out before the steam is introduced ( evacuation ).

In the Bowie-Dick test, a chemical indicator is sterilized in a gas-permeable container. If the air in the sterilizer is not sufficiently pumped out before the steam is introduced, the steam saturation in the test container does not reach the necessary concentration, whereby the defective function of the sterilizer becomes visible.

For larger sterilizers, such as those often found in hospitals, devices for the Bowie-Dick test are available, which simulate the difficulty of steam penetration of a package of 7 kg of textiles. In hospitals standardized sterilization containers with the dimensions 30 × 30 × 60 cm are used, which hold approximately this amount.

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