CST - CERTIFIED SURGICAL TECHNOLOGIST | VERIFIED
EXAM QUESTIONS AND ANSWERS - LATEST VERSION
2026/2027
CST - Certified Surgical Technologist
1. Which method is the most widely used in healthcare facilities to
sterilize heat- and moisture-stable surgical instruments?
A. Glutaraldehyde immersion
B. Dry heat oven
C. Saturated steam under pressure
D. Ethylene oxide gas
C. Saturated steam under pressure – Steam under pressure is rapid,
reliable, nontoxic, and inexpensive, so it is the method of choice for
compatible items.
2. What is the minimum exposure time for a wrapped instrument set
in a gravity-displacement steam sterilizer at 250°F (121°C)?
A. 3 minutes
B. 10 minutes
C. 60 minutes
D. 30 minutes
D. 30 minutes – Air is removed passively in a gravity cycle, so wrapped
sets need a longer exposure of 30 minutes.
CST Practice Examination | Page 1
,3. What is the usual exposure time for a wrapped instrument set in a
prevacuum steam sterilizer at 270°F (132°C)?
A. 4 minutes
B. 30 minutes
C. 1 minute
D. 15 minutes
A. 4 minutes – Mechanical air removal lets steam penetrate quickly, so a
4-minute exposure is sufficient.
4. Which organism is used in the biological indicator that monitors
steam sterilization?
A. Staphylococcus aureus
B. Geobacillus stearothermophilus
C. Clostridium tetani
D. Bacillus atrophaeus
B. Geobacillus stearothermophilus – Its spores resist moist heat, so
their death confirms that the cycle was effective.
5. Which spore is used to monitor ethylene oxide sterilization?
A. Bacillus atrophaeus
B. Escherichia coli
C. Clostridium botulinum
D. Geobacillus stearothermophilus
A. Bacillus atrophaeus – Bacillus atrophaeus is the resistant test
organism for ethylene oxide and dry heat.
6. What is the purpose of the Bowie-Dick test?
A. To confirm that an instrument tray is free of bioburden
B. To test the temperature of a dry heat oven
C. To verify air removal and steam penetration in a prevacuum
sterilizer
D. To measure the pH of an enzymatic cleaner
C. To verify air removal and steam penetration in a prevacuum
sterilizer – It is run in an empty prevacuum chamber to detect air leaks
or a failing vacuum system.
CST Practice Examination | Page 2
,7. Where should an internal chemical indicator be placed in an
instrument set?
A. Beneath the sterilizer shelf
B. Inside the package, in the area least accessible to steam
C. Only on the outside of the wrapper
D. On the sterilizer door
B. Inside the package, in the area least accessible to steam – An internal
indicator confirms that the sterilant reached the hardest area of the
pack to penetrate.
8. Which part of a sterile surgical gown is considered sterile?
A. Only the cuffs and gloves
B. The entire gown, including the back, shoulders, and axillae
C. The front of the gown below the waist only
D. The front from chest level to the level of the sterile field, and the
sleeves from 2 inches above the elbow to the cuff
D. The front from chest level to the level of the sterile field, and the
sleeves from 2 inches above the elbow to the cuff – These areas remain
in view and are least likely to touch non-sterile surfaces.
9. A sterile package is removed from the sterilizer and a moisture spot
is found on the wrapper. What should be done?
A. Use it if the spot is small
B. Dry it with a sterile towel and use it
C. Re-wrap it and use it as sterile
D. Consider it contaminated and do not use it
D. Consider it contaminated and do not use it – Moisture wicks
microorganisms through the wrapper, so a wet package is contaminated.
CST Practice Examination | Page 3
, 10. Event-related sterility means that the shelf life of a sterile package
depends on:
A. The color of the wrapper
B. The size of the package
C. A fixed expiration date only
D. Handling, storage conditions, and package integrity
D. Handling, storage conditions, and package integrity – Sterility lasts
until an event such as a tear, moisture, or compression compromises the
package.
11. Which surgical hand antiseptic provides persistent (residual)
antimicrobial activity?
A. Isopropyl alcohol alone
B. Plain soap
C. Chlorhexidine gluconate
D. Hydrogen peroxide
C. Chlorhexidine gluconate – Chlorhexidine binds to the skin and
continues to suppress microbes for hours.
12. Standard precautions should be applied to:
A. Only patients with bloodborne disease
B. All patients regardless of diagnosis
C. Only immunocompromised patients
D. Only patients with known infections
B. All patients regardless of diagnosis – Blood and body fluids of every
patient are treated as potentially infectious.
13. Which precaution is required for a patient with suspected active
pulmonary tuberculosis?
A. Standard precautions only
B. Contact precautions only
C. Airborne precautions with an N95 respirator
D. Droplet precautions with a surgical mask only
C. Airborne precautions with an N95 respirator – TB spreads on small
airborne particles and requires negative-pressure isolation and N95-
level protection.
CST Practice Examination | Page 4
EXAM QUESTIONS AND ANSWERS - LATEST VERSION
2026/2027
CST - Certified Surgical Technologist
1. Which method is the most widely used in healthcare facilities to
sterilize heat- and moisture-stable surgical instruments?
A. Glutaraldehyde immersion
B. Dry heat oven
C. Saturated steam under pressure
D. Ethylene oxide gas
C. Saturated steam under pressure – Steam under pressure is rapid,
reliable, nontoxic, and inexpensive, so it is the method of choice for
compatible items.
2. What is the minimum exposure time for a wrapped instrument set
in a gravity-displacement steam sterilizer at 250°F (121°C)?
A. 3 minutes
B. 10 minutes
C. 60 minutes
D. 30 minutes
D. 30 minutes – Air is removed passively in a gravity cycle, so wrapped
sets need a longer exposure of 30 minutes.
CST Practice Examination | Page 1
,3. What is the usual exposure time for a wrapped instrument set in a
prevacuum steam sterilizer at 270°F (132°C)?
A. 4 minutes
B. 30 minutes
C. 1 minute
D. 15 minutes
A. 4 minutes – Mechanical air removal lets steam penetrate quickly, so a
4-minute exposure is sufficient.
4. Which organism is used in the biological indicator that monitors
steam sterilization?
A. Staphylococcus aureus
B. Geobacillus stearothermophilus
C. Clostridium tetani
D. Bacillus atrophaeus
B. Geobacillus stearothermophilus – Its spores resist moist heat, so
their death confirms that the cycle was effective.
5. Which spore is used to monitor ethylene oxide sterilization?
A. Bacillus atrophaeus
B. Escherichia coli
C. Clostridium botulinum
D. Geobacillus stearothermophilus
A. Bacillus atrophaeus – Bacillus atrophaeus is the resistant test
organism for ethylene oxide and dry heat.
6. What is the purpose of the Bowie-Dick test?
A. To confirm that an instrument tray is free of bioburden
B. To test the temperature of a dry heat oven
C. To verify air removal and steam penetration in a prevacuum
sterilizer
D. To measure the pH of an enzymatic cleaner
C. To verify air removal and steam penetration in a prevacuum
sterilizer – It is run in an empty prevacuum chamber to detect air leaks
or a failing vacuum system.
CST Practice Examination | Page 2
,7. Where should an internal chemical indicator be placed in an
instrument set?
A. Beneath the sterilizer shelf
B. Inside the package, in the area least accessible to steam
C. Only on the outside of the wrapper
D. On the sterilizer door
B. Inside the package, in the area least accessible to steam – An internal
indicator confirms that the sterilant reached the hardest area of the
pack to penetrate.
8. Which part of a sterile surgical gown is considered sterile?
A. Only the cuffs and gloves
B. The entire gown, including the back, shoulders, and axillae
C. The front of the gown below the waist only
D. The front from chest level to the level of the sterile field, and the
sleeves from 2 inches above the elbow to the cuff
D. The front from chest level to the level of the sterile field, and the
sleeves from 2 inches above the elbow to the cuff – These areas remain
in view and are least likely to touch non-sterile surfaces.
9. A sterile package is removed from the sterilizer and a moisture spot
is found on the wrapper. What should be done?
A. Use it if the spot is small
B. Dry it with a sterile towel and use it
C. Re-wrap it and use it as sterile
D. Consider it contaminated and do not use it
D. Consider it contaminated and do not use it – Moisture wicks
microorganisms through the wrapper, so a wet package is contaminated.
CST Practice Examination | Page 3
, 10. Event-related sterility means that the shelf life of a sterile package
depends on:
A. The color of the wrapper
B. The size of the package
C. A fixed expiration date only
D. Handling, storage conditions, and package integrity
D. Handling, storage conditions, and package integrity – Sterility lasts
until an event such as a tear, moisture, or compression compromises the
package.
11. Which surgical hand antiseptic provides persistent (residual)
antimicrobial activity?
A. Isopropyl alcohol alone
B. Plain soap
C. Chlorhexidine gluconate
D. Hydrogen peroxide
C. Chlorhexidine gluconate – Chlorhexidine binds to the skin and
continues to suppress microbes for hours.
12. Standard precautions should be applied to:
A. Only patients with bloodborne disease
B. All patients regardless of diagnosis
C. Only immunocompromised patients
D. Only patients with known infections
B. All patients regardless of diagnosis – Blood and body fluids of every
patient are treated as potentially infectious.
13. Which precaution is required for a patient with suspected active
pulmonary tuberculosis?
A. Standard precautions only
B. Contact precautions only
C. Airborne precautions with an N95 respirator
D. Droplet precautions with a surgical mask only
C. Airborne precautions with an N95 respirator – TB spreads on small
airborne particles and requires negative-pressure isolation and N95-
level protection.
CST Practice Examination | Page 4
