CBET Sterilization and Infection Control Equipment 5

Question 1

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

Accepted Answer

Air cannot be fully displaced from enclosed spaces by gravity alone

Answer

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

Question 2

What does the D-value represent in sterilization science?

Accepted Answer

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

Answer

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

Question 3

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

Accepted Answer

Class 6 (emulating indicators)

Answer

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

Question 4

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

Accepted Answer

Residual moisture in the chamber or on devices

Answer

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

Question 5

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

Accepted Answer

99.97%

Answer

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.

CBET - Certified Biomedical Equipment Technician Practice Test