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Free CER Practice Questions

10 free, exam-style Certified Endoscope Reprocessor (CER) practice questions with answers and explanations. No signup required. Work through them below, then take the full free CER practice test to study every exam domain.

The CER exam has 150 questions and runs 3 hours.

These 10 free CER questions are organized by exam domain, so you can see how each part of the Certified Endoscope Reprocessor blueprint is tested. Reveal the answer and explanation under each question.

Domain 1: Microbiology and Infection Control 12% of exam

Question 1

A flexible gastroscope contacts intact mucous membranes but does not enter sterile tissue. Under the Spaulding classification, how is it categorized and what is the MINIMUM level of processing required?

  1. Critical device requiring sterilization
  2. Semi-critical device requiring only intermediate-level disinfection
  3. Semi-critical device requiring high-level disinfection
  4. Non-critical device requiring low-level disinfection
Show answer & explanation

Correct answer: C - Semi-critical device requiring high-level disinfection

Domain 2: Endoscope Purpose, Design and Structure 10% of exam

Question 2

Duodenoscopes have been linked to outbreaks of multidrug-resistant organisms even when reprocessing instructions were followed. Which design feature is MOST responsible for this reprocessing difficulty?

  1. The length of the insertion tube
  2. The elevator mechanism at the distal tip
  3. The forward-viewing distal lens
  4. The air/water channel opening
Show answer & explanation

Correct answer: B - The elevator mechanism at the distal tip

Domain 3: Work Area Design 12% of exam

Question 3

To prevent contaminated air from spreading to clean areas, how should the air pressure in the endoscope decontamination (soiled) area be maintained relative to adjacent areas?

  1. Positive pressure
  2. Negative pressure
  3. Equal (balanced) pressure
  4. Pressure is not relevant as long as ten air exchanges per hour occur
Show answer & explanation

Correct answer: B - Negative pressure

Domain 4: Endoscope Processing Steps 32% of exam

Question 4

Immediately after a colonoscopy is completed and the scope is removed from the patient, what is the FIRST action the reprocessing workflow requires?

  1. Wipe the insertion tube and flush the channels at the point of use
  2. Transport the scope to the decontamination room
  3. Perform a leak test before anything else
  4. Submerge the scope in enzymatic detergent for manual cleaning
Show answer & explanation

Correct answer: A - Wipe the insertion tube and flush the channels at the point of use

Question 5

At what point in the reprocessing sequence is a leak test performed?

  1. After manual cleaning but before high-level disinfection
  2. After high-level disinfection, just before drying
  3. Only when visible damage to the scope is already suspected
  4. Before manual cleaning and before the scope is fully submerged
Show answer & explanation

Correct answer: D - Before manual cleaning and before the scope is fully submerged

Question 6

Which step in endoscope reprocessing is considered the MOST important, because no subsequent step can compensate for its failure?

  1. High-level disinfection
  2. Manual cleaning
  3. Forced-air drying
  4. Sterilization with ethylene oxide
Show answer & explanation

Correct answer: B - Manual cleaning

Question 7

Before each use of a reusable 0.55% ortho-phthalaldehyde (OPA) high-level disinfectant solution, a test strip confirms the solution is at or above its minimum effective concentration (MEC). For OPA, that MEC is:

  1. 0.3%
  2. 0.55%
  3. 1.5%
  4. 2.4%
Show answer & explanation

Correct answer: A - 0.3%

Question 8

A facility wants to add one of the FDA's 2015 supplemental measures to enhance duodenoscope reprocessing beyond standard high-level disinfection. Which option is one of those supplemental measures?

  1. Transitioning to a duodenoscope with a disposable distal cap
  2. Extending the air/water channel flush to five minutes
  3. Increasing the manual cleaning detergent concentration
  4. Repeat (double) high-level disinfection
Show answer & explanation

Correct answer: D - Repeat (double) high-level disinfection

Domain 5: Endoscope Handling, Transport and Storage 16% of exam

Question 9

ANSI/AAMI ST91:2021 describes two cabinet types for storing processed flexible endoscopes. What distinguishes a drying cabinet from a conventional storage cabinet?

  1. A drying cabinet circulates filtered air through each endoscope channel; a conventional cabinet does not
  2. A conventional cabinet circulates filtered air through each channel; a drying cabinet only warms the exterior
  3. A drying cabinet uses HEPA-filtered air, whereas a conventional cabinet relies on unfiltered ambient room air
  4. A drying cabinet is held at negative pressure, whereas a conventional cabinet is held at positive pressure
Show answer & explanation

Correct answer: A - A drying cabinet circulates filtered air through each endoscope channel; a conventional cabinet does not

Domain 6: Endoscope Tracking, Repair and System Maintenance 10% of exam

Question 10

A loaner duodenoscope arrives from another facility in sealed packaging labeled as ready for use. Before it is used on a patient at the receiving facility, it should be:

  1. Used directly, since the sending facility already documented reprocessing
  2. Stored for 24 hours and then used without reprocessing
  3. Reprocessed according to the manufacturer's IFU before first use
  4. High-level disinfected only if the packaging seal appears broken
Show answer & explanation

Correct answer: C - Reprocessed according to the manufacturer's IFU before first use

The rest of the CER blueprint

The CER exam also covers these domains. Drill them in the full free practice test:

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