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STERILE PROCESSING / SURGICAL TECHNOLOGY
(STR) Exam 2026-2027 BANK QUESTIONS WITH
DETAILED VERIFIED ANSWERS EXAM QUESTIONS
WILL COME FROM HERE (100% Latest Already Graded
A+
1. The process that destroys all microorganisms including spores is
termed:
A. Sanitization
B. Disinfection
C. Sterilization
D. Antisepsis
Answer: C. Sterilization
Explanation: Sterilization is the complete elimination or destruction of
all forms of microbial life, including bacterial spores. Sanitization
reduces microbial count to safe levels, disinfection eliminates vegetative
pathogens but not necessarily spores, and antisepsis refers to the
application of antimicrobial agents to living tissue.
2. The recommended temperature for steam sterilization under
pressure is:
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A. 121°C (250°F)
B. 132°C (270°F)
C. 145°C (293°F)
D. 160°C (320°F)
Answer: B. 132°C (270°F)
Explanation: While 121°C at 15 psi is traditional for gravity
displacement sterilizers, the recommended standard temperature for
steam sterilization is 132°C to 135°C (270°F to 275°F) for dynamic air
removal sterilizers. The higher temperature ensures more efficient
sterilization with shorter exposure times.
3. Which of the following is NOT a recommended method for biological
monitoring of sterilizers?
A. Geobacillus stearothermophilus for steam
B. Bacillus atrophaeus for ethylene oxide
C. Escherichia coli for dry heat
D. Geobacillus stearothermophilus for hydrogen peroxide gas plasma
Answer: C. Escherichia coli for dry heat
Explanation: E. coli is not used as a biological indicator for any
sterilization process. For dry heat sterilization, Bacillus atrophaeus
(formerly Bacillus subtilis) is the appropriate biological indicator
organism. Geobacillus stearothermophilus is used for steam, hydrogen
peroxide gas plasma, and liquid chemical sterilization processes.
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4. The Bowie-Dick test is performed to:
A. Test biological lethality
B. Assess steam penetration in dynamic air removal sterilizers
C. Evaluate chemical indicator performance
D. Measure sterilizer chamber temperature
Answer: B. Assess steam penetration in dynamic air removal sterilizers
Explanation: The Bowie-Dick test is a diagnostic test performed daily on
dynamic-air-removal (prevacuum) steam sterilizers to evaluate air
removal and steam penetration. It is not a biological test and does not
verify sterilization; rather, it detects air leaks and inadequate air
removal that could compromise sterilization.
5. Which solution is considered a high-level disinfectant when used at
appropriate concentrations and contact times?
A. 70% isopropyl alcohol
B. 2% glutaraldehyde
C. 10% povidone-iodine
D. 3% hydrogen peroxide
Answer: B. 2% glutaraldehyde
Explanation: Glutaraldehyde at 2% concentration is classified as a high-
level disinfectant capable of killing all microorganisms except large
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numbers of bacterial spores when used with proper contact time. It is
commonly used for heat-sensitive semi-critical devices. Isopropyl alcohol
is an intermediate-level disinfectant, povidone-iodine is an antiseptic,
and hydrogen peroxide has varying efficacy depending on
concentration.
6. The primary purpose of using a biological indicator in a sterilization
process is to:
A. Monitor temperature fluctuations
B. Confirm the presence of viable organisms after the cycle
C. Provide direct evidence of sterility
D. Test the mechanical function of the sterilizer
Answer: B. Confirm the presence of viable organisms after the cycle
Explanation: Biological indicators provide direct evidence that the
sterilization process has killed the most resistant organisms. A negative
result after incubation indicates that the spores have been killed,
demonstrating that the sterilizer delivered a lethal challenge. Biological
monitoring is considered the highest standard for verifying sterilization
efficacy.
7. In the sterile processing department, the term "IFU" refers to:
A. Integrated Function Unit
B. Instructions for Use
C. Instrument Fixation Unit
STERILE PROCESSING / SURGICAL TECHNOLOGY
(STR) Exam 2026-2027 BANK QUESTIONS WITH
DETAILED VERIFIED ANSWERS EXAM QUESTIONS
WILL COME FROM HERE (100% Latest Already Graded
A+
1. The process that destroys all microorganisms including spores is
termed:
A. Sanitization
B. Disinfection
C. Sterilization
D. Antisepsis
Answer: C. Sterilization
Explanation: Sterilization is the complete elimination or destruction of
all forms of microbial life, including bacterial spores. Sanitization
reduces microbial count to safe levels, disinfection eliminates vegetative
pathogens but not necessarily spores, and antisepsis refers to the
application of antimicrobial agents to living tissue.
2. The recommended temperature for steam sterilization under
pressure is:
,2|Page
A. 121°C (250°F)
B. 132°C (270°F)
C. 145°C (293°F)
D. 160°C (320°F)
Answer: B. 132°C (270°F)
Explanation: While 121°C at 15 psi is traditional for gravity
displacement sterilizers, the recommended standard temperature for
steam sterilization is 132°C to 135°C (270°F to 275°F) for dynamic air
removal sterilizers. The higher temperature ensures more efficient
sterilization with shorter exposure times.
3. Which of the following is NOT a recommended method for biological
monitoring of sterilizers?
A. Geobacillus stearothermophilus for steam
B. Bacillus atrophaeus for ethylene oxide
C. Escherichia coli for dry heat
D. Geobacillus stearothermophilus for hydrogen peroxide gas plasma
Answer: C. Escherichia coli for dry heat
Explanation: E. coli is not used as a biological indicator for any
sterilization process. For dry heat sterilization, Bacillus atrophaeus
(formerly Bacillus subtilis) is the appropriate biological indicator
organism. Geobacillus stearothermophilus is used for steam, hydrogen
peroxide gas plasma, and liquid chemical sterilization processes.
,3|Page
4. The Bowie-Dick test is performed to:
A. Test biological lethality
B. Assess steam penetration in dynamic air removal sterilizers
C. Evaluate chemical indicator performance
D. Measure sterilizer chamber temperature
Answer: B. Assess steam penetration in dynamic air removal sterilizers
Explanation: The Bowie-Dick test is a diagnostic test performed daily on
dynamic-air-removal (prevacuum) steam sterilizers to evaluate air
removal and steam penetration. It is not a biological test and does not
verify sterilization; rather, it detects air leaks and inadequate air
removal that could compromise sterilization.
5. Which solution is considered a high-level disinfectant when used at
appropriate concentrations and contact times?
A. 70% isopropyl alcohol
B. 2% glutaraldehyde
C. 10% povidone-iodine
D. 3% hydrogen peroxide
Answer: B. 2% glutaraldehyde
Explanation: Glutaraldehyde at 2% concentration is classified as a high-
level disinfectant capable of killing all microorganisms except large
, 4|Page
numbers of bacterial spores when used with proper contact time. It is
commonly used for heat-sensitive semi-critical devices. Isopropyl alcohol
is an intermediate-level disinfectant, povidone-iodine is an antiseptic,
and hydrogen peroxide has varying efficacy depending on
concentration.
6. The primary purpose of using a biological indicator in a sterilization
process is to:
A. Monitor temperature fluctuations
B. Confirm the presence of viable organisms after the cycle
C. Provide direct evidence of sterility
D. Test the mechanical function of the sterilizer
Answer: B. Confirm the presence of viable organisms after the cycle
Explanation: Biological indicators provide direct evidence that the
sterilization process has killed the most resistant organisms. A negative
result after incubation indicates that the spores have been killed,
demonstrating that the sterilizer delivered a lethal challenge. Biological
monitoring is considered the highest standard for verifying sterilization
efficacy.
7. In the sterile processing department, the term "IFU" refers to:
A. Integrated Function Unit
B. Instructions for Use
C. Instrument Fixation Unit
