Certified Surgical Technologist (CST) Exam
Questions and Answers| Latest Update| Guaranteed Pass
,1. Which of the following is considered the single most important practice for
preventing surgical site infection?
A. Prophylactic antibiotic administration
B. Proper surgical hand scrub and maintenance of sterile technique
C. Shaving the surgical site the night before surgery
D. Use of laminar airflow in the operating room
Answer: B
Rationale: Strict adherence to aseptic and sterile technique, beginning with an
effective surgical hand scrub, is the foundation of surgical site infection prevention.
Antibiotics and environmental controls are adjuncts, not substitutes, for
meticulous sterile technique.
2. During a surgical scrub, the scrubbed hands and arms should be held:
A. Below the waist at all times
B. Above the elbow and below the shoulder
C. Above waist level and below shoulder level, in front of the body
D. At the sides of the body
Answer: C
Rationale: After scrubbing, hands and arms are held above the waist and below
the shoulders, in front of the body, allowing water and contaminants to drip from
the least clean area (elbow) rather than recontaminating the hands, which are
considered the cleanest area.
3. Which item is considered unsterile once a sterile field has been established?
A. The top of a draped table
B. The area 1 inch from the edge of a sterile field
C. Items above the level of the surgeon's waist
D. Instruments on the Mayo stand
Answer: B
Rationale: The outer 1-inch border of a sterile field, table drape, or wrapper is
considered unsterile/contaminated because it is difficult to control and may have
been in contact with unsterile surfaces, a standard principle of aseptic technique.
4. A sterile package that has become wet during storage or handling should be
considered:
, A. Still sterile if dried promptly
B. Contaminated, because moisture allows wicking of microorganisms through
the wrapper
C. Sterile only if resealed
D. Sterile for 24 hours after drying
Answer: B
Rationale: Moisture provides a pathway (wicking) for microorganisms to travel
through a wrapper into the sterile contents, so any wet package is considered
contaminated regardless of how it became wet and must be reprocessed.
5. Which of the following actions by the scrub person violates sterile technique?
A. Keeping hands within the sterile field at or above waist level
B. Turning their back toward the sterile field to reach for an item
C. Facing the sterile field at all times
D. Passing instruments handle-first to the surgeon
Answer: B
Rationale: A scrubbed person must never turn their back to the sterile field, as this
risks inadvertent contamination of the sterile gown from unsterile items or
personnel behind them; sterile personnel must always face the sterile field.
6. What is the recommended method for pouring a sterile solution into a basin
on the sterile field?
A. Pour rapidly from a height of at least 12 inches to avoid splash
B. Pour slowly and close to the basin, avoiding splashing, with the circulator
holding the label to prevent smearing
C. Have the scrub person hold the bottle and pour it themselves
D. Pour directly over instruments to rinse them
Answer: B
Rationale: Sterile solutions should be poured slowly and close to (but not touching)
the sterile receptacle to prevent splash, which can cause strike-through
contamination of the drapes; the circulator reads the label aloud and controls the
pour while the scrub holds the basin at the edge of the table.
7. Which sterilization method is most appropriate for heat- and moisture-
sensitive items such as certain endoscopes?
, A. Steam autoclave sterilization
B. Dry heat sterilization
C. Ethylene oxide (EtO) or low-temperature hydrogen peroxide gas plasma
sterilization
D. Boiling water
Answer: C
Rationale: Ethylene oxide and low-temperature hydrogen peroxide gas plasma
sterilization are used for heat- and moisture-sensitive instruments because they do
not require the high temperatures and moisture of steam autoclaving, which
would damage delicate equipment.
8. Steam sterilization (autoclaving) achieves microbial destruction primarily
through:
A. Oxidation of cell membranes by gas
B. Coagulation and denaturation of microbial proteins under heat and pressure
C. Ultraviolet radiation
D. Ionizing radiation
Answer: B
Rationale: Steam under pressure raises the temperature sufficiently (typically 250-
270°F) to coagulate and denature microbial proteins, achieving sterilization; this
requires direct steam contact, adequate time, temperature, and pressure.
9. A biological indicator used to verify sterilization effectiveness typically
contains spores of which organism for steam sterilization?
A. Staphylococcus aureus
B. Geobacillus stearothermophilus
C. Escherichia coli
D. Clostridium tetani
Answer: B
Rationale: Geobacillus stearothermophilus spores are highly resistant to steam
sterilization and are used as biological indicators; failure to kill these spores
indicates the sterilization cycle was inadequate, prompting reprocessing and
equipment evaluation.
Questions and Answers| Latest Update| Guaranteed Pass
,1. Which of the following is considered the single most important practice for
preventing surgical site infection?
A. Prophylactic antibiotic administration
B. Proper surgical hand scrub and maintenance of sterile technique
C. Shaving the surgical site the night before surgery
D. Use of laminar airflow in the operating room
Answer: B
Rationale: Strict adherence to aseptic and sterile technique, beginning with an
effective surgical hand scrub, is the foundation of surgical site infection prevention.
Antibiotics and environmental controls are adjuncts, not substitutes, for
meticulous sterile technique.
2. During a surgical scrub, the scrubbed hands and arms should be held:
A. Below the waist at all times
B. Above the elbow and below the shoulder
C. Above waist level and below shoulder level, in front of the body
D. At the sides of the body
Answer: C
Rationale: After scrubbing, hands and arms are held above the waist and below
the shoulders, in front of the body, allowing water and contaminants to drip from
the least clean area (elbow) rather than recontaminating the hands, which are
considered the cleanest area.
3. Which item is considered unsterile once a sterile field has been established?
A. The top of a draped table
B. The area 1 inch from the edge of a sterile field
C. Items above the level of the surgeon's waist
D. Instruments on the Mayo stand
Answer: B
Rationale: The outer 1-inch border of a sterile field, table drape, or wrapper is
considered unsterile/contaminated because it is difficult to control and may have
been in contact with unsterile surfaces, a standard principle of aseptic technique.
4. A sterile package that has become wet during storage or handling should be
considered:
, A. Still sterile if dried promptly
B. Contaminated, because moisture allows wicking of microorganisms through
the wrapper
C. Sterile only if resealed
D. Sterile for 24 hours after drying
Answer: B
Rationale: Moisture provides a pathway (wicking) for microorganisms to travel
through a wrapper into the sterile contents, so any wet package is considered
contaminated regardless of how it became wet and must be reprocessed.
5. Which of the following actions by the scrub person violates sterile technique?
A. Keeping hands within the sterile field at or above waist level
B. Turning their back toward the sterile field to reach for an item
C. Facing the sterile field at all times
D. Passing instruments handle-first to the surgeon
Answer: B
Rationale: A scrubbed person must never turn their back to the sterile field, as this
risks inadvertent contamination of the sterile gown from unsterile items or
personnel behind them; sterile personnel must always face the sterile field.
6. What is the recommended method for pouring a sterile solution into a basin
on the sterile field?
A. Pour rapidly from a height of at least 12 inches to avoid splash
B. Pour slowly and close to the basin, avoiding splashing, with the circulator
holding the label to prevent smearing
C. Have the scrub person hold the bottle and pour it themselves
D. Pour directly over instruments to rinse them
Answer: B
Rationale: Sterile solutions should be poured slowly and close to (but not touching)
the sterile receptacle to prevent splash, which can cause strike-through
contamination of the drapes; the circulator reads the label aloud and controls the
pour while the scrub holds the basin at the edge of the table.
7. Which sterilization method is most appropriate for heat- and moisture-
sensitive items such as certain endoscopes?
, A. Steam autoclave sterilization
B. Dry heat sterilization
C. Ethylene oxide (EtO) or low-temperature hydrogen peroxide gas plasma
sterilization
D. Boiling water
Answer: C
Rationale: Ethylene oxide and low-temperature hydrogen peroxide gas plasma
sterilization are used for heat- and moisture-sensitive instruments because they do
not require the high temperatures and moisture of steam autoclaving, which
would damage delicate equipment.
8. Steam sterilization (autoclaving) achieves microbial destruction primarily
through:
A. Oxidation of cell membranes by gas
B. Coagulation and denaturation of microbial proteins under heat and pressure
C. Ultraviolet radiation
D. Ionizing radiation
Answer: B
Rationale: Steam under pressure raises the temperature sufficiently (typically 250-
270°F) to coagulate and denature microbial proteins, achieving sterilization; this
requires direct steam contact, adequate time, temperature, and pressure.
9. A biological indicator used to verify sterilization effectiveness typically
contains spores of which organism for steam sterilization?
A. Staphylococcus aureus
B. Geobacillus stearothermophilus
C. Escherichia coli
D. Clostridium tetani
Answer: B
Rationale: Geobacillus stearothermophilus spores are highly resistant to steam
sterilization and are used as biological indicators; failure to kill these spores
indicates the sterilization cycle was inadequate, prompting reprocessing and
equipment evaluation.
