CRCST practice test: Cleaning, Decontamination and Disinfection

10 questions · about 12 minutes. Pick an answer to see whether you’re right and why.

1. Question 1 of 10Which step must always come before disinfection or sterilization?

   A.PackagingB.CleaningC.Biological monitoringD.Aeration
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   Answer: B. Cleaning

   CDC’s guideline says meticulous cleaning must precede disinfection and sterilization: organic material and salts left on an item can shield microorganisms and reduce the effectiveness of the process.

2. Question 2 of 10Why are soiled instruments kept moist and free of gross soil at the point of use?

   A.Dried soil is much harder to remove and can lead to biofilm formationB.Moisture sterilizes the instruments during transportC.Dry instruments cannot be counted accuratelyD.It allows instruments to skip manual cleaning
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   Answer: A. Dried soil is much harder to remove and can lead to biofilm formation

   Point-of-use treatment (wiping gross soil, keeping items moist with water or a product made for it) stops blood and tissue from drying on, which makes cleaning harder and can protect microorganisms.

3. Question 3 of 10Why should the initial rinse of instruments soiled with blood not use hot water?

   A.Hot water damages the instrument’s stainless steelB.Hot water deactivates the sterilizerC.Hot water is only used after sterilizationD.Heat coagulates protein, making the soil stick to the instrument
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   Answer: D. Heat coagulates protein, making the soil stick to the instrument

   Protein such as blood coagulates in hot water and bonds to the surface. Cool or lukewarm water, or the temperature the detergent’s IFU specifies, keeps soil removable.

4. Question 4 of 10During manual cleaning, how does a technician reduce the creation of aerosols?

   A.Brush instruments above the sink so the spray can be seenB.Use the highest-pressure water gun availableC.Brush instruments below the surface of the cleaning solutionD.Shake instruments dry after rinsing
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   Answer: C. Brush instruments below the surface of the cleaning solution

   Keeping items submerged while brushing contains splashes and aerosols. HSPA’s outline lists prevention of aerosols under the manual cleaning process.

5. Question 5 of 10How does an ultrasonic cleaner remove soil?

   A.High-pressure steam jets aimed at the instrumentsB.Cavitation: sound waves create tiny bubbles that implode and dislodge soil from crevicesC.Ultraviolet light that destroys soilD.Heat that bakes soil off the surface
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   Answer: B. Cavitation: sound waves create tiny bubbles that implode and dislodge soil from crevices

   Ultrasonic cleaners use cavitation to clean hard-to-reach areas such as box locks and serrations. Gross soil is removed first, and the cleaner’s efficacy is tested on a schedule.

6. Question 6 of 10What PPE should a technician wear when manually cleaning instruments in decontamination?

   A.Fluid-resistant gown, gloves, face protection (mask with goggles or a face shield), and head and shoe coversB.Gloves onlyC.A surgical mask onlyD.A cloth lab coat and safety glasses
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   Answer: A. Fluid-resistant gown, gloves, face protection (mask with goggles or a face shield), and head and shoe covers

   Decontamination involves splashes of blood and body fluids, so full barrier PPE is needed. OSHA’s Bloodborne Pathogens Standard requires appropriate PPE for exposure tasks.

7. Question 7 of 10A reusable high-level disinfectant solution is checked with a test strip before use. What is being verified?

   A.That the solution is sterileB.That the solution has a neutral pHC.That the solution is at room temperatureD.That the solution is at or above its minimum effective concentration (MEC)
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   Answer: D. That the solution is at or above its minimum effective concentration (MEC)

   Reusable high-level disinfectants are diluted by use and lose strength. Testing the MEC, and documenting the result, confirms the solution is still effective. HSPA’s outline lists MEC under disinfection.

8. Question 8 of 10Under the Spaulding classification, an item that contacts intact skin only needs at least which process?

   A.SterilizationB.High-level disinfectionC.Low-level disinfectionD.No cleaning at all
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   Answer: C. Low-level disinfection

   Noncritical items (blood pressure cuffs, bed rails) touch only intact skin and need cleaning and low-level disinfection. Semicritical items need high-level disinfection; critical items need sterilization (CDC).

9. Question 9 of 10Toxic anterior segment syndrome (TASS) is linked to residues on which instruments?

   A.Orthopedic power drillsB.Ophthalmic (eye surgery) instrumentsC.Laparoscopic graspersD.Blood pressure cuffs
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   Answer: B. Ophthalmic (eye surgery) instruments

   TASS is an acute inflammation after anterior-segment eye surgery that can be caused by residues such as detergents on intraocular instruments. Follow the IFU’s cleaning and rinsing steps exactly. HSPA’s outline names TASS.

10. Question 10 of 10Why are washer-disinfectors and ultrasonic cleaners tested with cleaning verification tests?

    A.To confirm the equipment is actually removing soil before items move onB.To replace the need for visual inspectionC.To measure the sterilizer’s temperatureD.To check the water hardness for billing
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    Answer: A. To confirm the equipment is actually removing soil before items move on

    Efficacy tests show whether a cycle can remove a known soil challenge. HSPA’s outline lists efficacy testing of washers, ultrasonic cleaners, AERs and cart washers, with documented results.