CRCST Sterilization Methods 2

Question 1

What is the primary mechanism by which ethylene oxide (EtO) achieves sterilization?

Accepted Answer

Alkylating DNA and proteins

Answer

EtO sterilizes by alkylating the DNA and proteins of microorganisms, preventing reproduction and causing cell death.

Question 2

Which parameter is NOT part of the EtO sterilization cycle?

Accepted Answer

UV exposure

Answer

UV exposure is not a parameter in EtO sterilization; the key parameters are gas concentration, humidity, temperature, and exposure time.

Question 3

Hydrogen peroxide gas plasma sterilization is contraindicated for items made of which material?

Accepted Answer

Cellulose-based materials

Answer

Cellulose-based materials (paper, linen, cotton) absorb hydrogen peroxide and are incompatible with H2O2 gas plasma sterilization.

Question 4

What does the term 'D-value' represent in sterilization science?

Accepted Answer

The time needed to reduce a microbial population by 90%

Answer

The D-value (decimal reduction time) is the time required to reduce a microbial population by one log (90%) at a given set of conditions.

Question 5

Which biological indicator organism is the standard for validating steam sterilization cycles?

Accepted Answer

Geobacillus stearothermophilus

Answer

Geobacillus stearothermophilus spores are the standard biological indicator for steam sterilization because of their high heat resistance.

(CRCST) Certified Registered Central Service Technician Exam Practice Test