IAHCSMM CRCST Certification Practice Exam 2025/2026
Questions and Answers
QUESTION 1
QUESTION: Which part of the Central Service (CS) workflow is primarily responsible for breaking
down bioburden on instruments?
A. Sterile storage
B. Decontamination area
C. Preparation & packaging area
D. Distribution
CORRECT ANSWER: B.
RATIONALE: Bioburden removal occurs during decontamination, where instruments are cleaned
and disinfected before inspection and packaging.
QUESTION 2
QUESTION: Enzymatic detergents are designed to:
A. Sterilize instruments
B. Break down organic soils such as blood and tissue
C. Neutralize alkaline residues
D. Remove rust stains
CORRECT ANSWER: B.
RATIONALE: Enzymes catalyze breakdown of proteins, fats, and carbohydrates, improving
cleaning effectiveness prior to sterilization.
QUESTION 3
QUESTION: Which factor does not affect the efficacy of cleaning solutions?
A. Water quality
B. Contact time
C. Concentration
D. Instrument labeling
CORRECT ANSWER: D.
,RATIONALE: Labeling has no effect on detergent function; temperature, concentration, and
water condition do.
QUESTION 4
QUESTION: What is the safe order of workflow in a Central Service Department?
A. Sterile → Soiled → Clean
B. Soiled → Clean → Sterile
C. Clean → Soiled → Sterile
D. Soiled → Sterile → Clean
CORRECT ANSWER: B.
RATIONALE: Design maintains one-way movement to prevent cross-contamination.
QUESTION 5
QUESTION: Hard water in decontamination can cause:
A. Reduced detergent efficiency and mineral deposits
B. Excess foam in ultrasonic cleaners
C. Rapid instrument corrosion protection
D. Automatic neutral pH control
CORRECT ANSWER: A.
RATIONALE: Calcium and magnesium ions bind with detergents and leave scale on instruments.
QUESTION 6
QUESTION: The main purpose of ultrasonic cleaning is to:
A. Kill microorganisms
B. Remove soil using cavitation
C. Apply lubricant
D. Rinse during sterilization
CORRECT ANSWER: B.
RATIONALE: Microscopic bubbles formed by cavitation dislodge debris from hard-to-reach
instrument areas.
,QUESTION 7
QUESTION: PPE in the decontamination area must include:
A. Lab coat and hair cover only
B. Fluid-resistant gown, gloves, face shield, and mask
C. Non-sterile gloves only
D. Apron and cap only
CORRECT ANSWER: B.
RATIONALE: Protection prevents exposure to biological and chemical contaminants.
QUESTION 8
QUESTION: Which step is performed immediately after cleaning but before inspection?
A. Instrument count
B. Rinsing and drying
C. Lubrication
D. Assembly
CORRECT ANSWER: B.
RATIONALE: Drying prevents corrosion and allows proper inspection for cleanliness.
QUESTION 9
QUESTION: Instruments hinged or with box locks should be:
A. Closed tightly for sterilization
B. Fully open during cleaning and sterilization
C. Partially open in storage
D. Sent out sealed
CORRECT ANSWER: B.
RATIONALE: Open positioning ensures steam or gas contact and thorough cleaning.
QUESTION 10
, QUESTION: The most critical parameter for steam sterilization effectiveness is:
A. Temperature
B. Chamber size
C. Air pressure
D. Wrapped load material
CORRECT ANSWER: A.
RATIONALE: Moist heat requires correct temperature (121–132°C) plus time and pressure to
achieve sterilization.
QUESTION 11
QUESTION: Which test verifies proper air removal and steam penetration in pre-vacuum
sterilizers?
A. Bowie-Dick test
B. Biological indicator
C. Chemical indicator
D. Leak test
CORRECT ANSWER: A.
RATIONALE: Bowie-Dick assesses vacuum efficiency, ensuring even steam penetration.
QUESTION 12
QUESTION: What biological indicator organism is used to monitor steam sterilization?
A. Bacillus atrophaeus
B. Geobacillus stearothermophilus
C. Clostridium botulinum
D. Staphylococcus aureus
CORRECT ANSWER: B.
RATIONALE: G. stearothermophilus spores resist moist heat—ideal for verifying sterilizer
lethality.
QUESTION 13
Questions and Answers
QUESTION 1
QUESTION: Which part of the Central Service (CS) workflow is primarily responsible for breaking
down bioburden on instruments?
A. Sterile storage
B. Decontamination area
C. Preparation & packaging area
D. Distribution
CORRECT ANSWER: B.
RATIONALE: Bioburden removal occurs during decontamination, where instruments are cleaned
and disinfected before inspection and packaging.
QUESTION 2
QUESTION: Enzymatic detergents are designed to:
A. Sterilize instruments
B. Break down organic soils such as blood and tissue
C. Neutralize alkaline residues
D. Remove rust stains
CORRECT ANSWER: B.
RATIONALE: Enzymes catalyze breakdown of proteins, fats, and carbohydrates, improving
cleaning effectiveness prior to sterilization.
QUESTION 3
QUESTION: Which factor does not affect the efficacy of cleaning solutions?
A. Water quality
B. Contact time
C. Concentration
D. Instrument labeling
CORRECT ANSWER: D.
,RATIONALE: Labeling has no effect on detergent function; temperature, concentration, and
water condition do.
QUESTION 4
QUESTION: What is the safe order of workflow in a Central Service Department?
A. Sterile → Soiled → Clean
B. Soiled → Clean → Sterile
C. Clean → Soiled → Sterile
D. Soiled → Sterile → Clean
CORRECT ANSWER: B.
RATIONALE: Design maintains one-way movement to prevent cross-contamination.
QUESTION 5
QUESTION: Hard water in decontamination can cause:
A. Reduced detergent efficiency and mineral deposits
B. Excess foam in ultrasonic cleaners
C. Rapid instrument corrosion protection
D. Automatic neutral pH control
CORRECT ANSWER: A.
RATIONALE: Calcium and magnesium ions bind with detergents and leave scale on instruments.
QUESTION 6
QUESTION: The main purpose of ultrasonic cleaning is to:
A. Kill microorganisms
B. Remove soil using cavitation
C. Apply lubricant
D. Rinse during sterilization
CORRECT ANSWER: B.
RATIONALE: Microscopic bubbles formed by cavitation dislodge debris from hard-to-reach
instrument areas.
,QUESTION 7
QUESTION: PPE in the decontamination area must include:
A. Lab coat and hair cover only
B. Fluid-resistant gown, gloves, face shield, and mask
C. Non-sterile gloves only
D. Apron and cap only
CORRECT ANSWER: B.
RATIONALE: Protection prevents exposure to biological and chemical contaminants.
QUESTION 8
QUESTION: Which step is performed immediately after cleaning but before inspection?
A. Instrument count
B. Rinsing and drying
C. Lubrication
D. Assembly
CORRECT ANSWER: B.
RATIONALE: Drying prevents corrosion and allows proper inspection for cleanliness.
QUESTION 9
QUESTION: Instruments hinged or with box locks should be:
A. Closed tightly for sterilization
B. Fully open during cleaning and sterilization
C. Partially open in storage
D. Sent out sealed
CORRECT ANSWER: B.
RATIONALE: Open positioning ensures steam or gas contact and thorough cleaning.
QUESTION 10
, QUESTION: The most critical parameter for steam sterilization effectiveness is:
A. Temperature
B. Chamber size
C. Air pressure
D. Wrapped load material
CORRECT ANSWER: A.
RATIONALE: Moist heat requires correct temperature (121–132°C) plus time and pressure to
achieve sterilization.
QUESTION 11
QUESTION: Which test verifies proper air removal and steam penetration in pre-vacuum
sterilizers?
A. Bowie-Dick test
B. Biological indicator
C. Chemical indicator
D. Leak test
CORRECT ANSWER: A.
RATIONALE: Bowie-Dick assesses vacuum efficiency, ensuring even steam penetration.
QUESTION 12
QUESTION: What biological indicator organism is used to monitor steam sterilization?
A. Bacillus atrophaeus
B. Geobacillus stearothermophilus
C. Clostridium botulinum
D. Staphylococcus aureus
CORRECT ANSWER: B.
RATIONALE: G. stearothermophilus spores resist moist heat—ideal for verifying sterilizer
lethality.
QUESTION 13
