Sterilization and Infection Control Equipment Flashcards

A gravity displacement autoclave is unable to sterilize items with long narrow lumens because:

Answer: Air cannot be fully displaced from enclosed spaces by gravity alone

Gravity displacement relies on steam displacing air downward, but trapped air in lumens prevents steam contact with internal surfaces.

What does the D-value represent in sterilization science?

Answer: The time or dose needed to reduce the microbial population by 90%

The D-value (decimal reduction value) is the time or radiation dose required to reduce a microbial population by one log (90%).

Which class of chemical indicators provides the most information about sterilization cycle conditions?

Answer: Class 6 (emulating indicators)

Class 6 emulating indicators react to all critical parameters of a specific sterilization cycle and are the most informative chemical indicators.

During vaporized hydrogen peroxide (VHP) sterilization, which condition causes cycle failure?

Answer: Residual moisture in the chamber or on devices

Residual moisture reacts with and depletes hydrogen peroxide vapor, reducing sterilant concentration below effective levels.

A HEPA filter used in a biological safety cabinet must retain what minimum percentage of particles at 0.3 microns?

Answer: 99.97%

HEPA filters are defined by their ability to capture at least 99.97% of particles at the most penetrating particle size of 0.3 microns.

Which sterilization method is most appropriate for heat-sensitive fiber optic endoscopes that cannot be immersed?

Answer: Ethylene oxide gas sterilization

EtO sterilization operates at low temperatures and can process complex heat-sensitive devices including non-immersible optics.

The sterility assurance level (SAL) required for critical medical devices classified by the Spaulding system is:

Answer: 10⁻⁶

A SAL of 10⁻⁶ is the regulatory standard for critical devices, meaning a one-in-a-million probability of a viable organism remaining.