Certified Endoscope Reprocessor (CER) Exam — Questions and Answers

Question 1: What is the purpose of waterproof tape in endoscope reprocessing?

To prevent water from entering the endoscope during reprocessing
To secure the endoscope during transportation
To permanently seal leaks in the endoscope
To temporarily seal a leaking endoscope and allow it to be disinfected (Correct answer)

Correct answer: To temporarily seal a leaking endoscope and allow it to be disinfected

Explanation: <br> Waterproof tape can be used as a temporary solution to seal a leaking endoscope, ensuring that it can still be disinfected properly. It is not meant for permanent sealing or preventing water from entering the endoscope during reprocessing.

Question 2: Under Joint Commission standards, what must be documented after every endoscope reprocessing cycle?

Scope identifier, reprocessing method, operator, date, and MEC test results (Correct answer)
Operator name and time only
Only the scope serial number and date
Patient name associated with prior use

Correct answer: Scope identifier, reprocessing method, operator, date, and MEC test results

The Joint Commission requires traceability documentation that links each scope to its reprocessing record, including disinfectant concentration testing and the responsible operator.

Question 3: During a QA review, it is found that a technician skipped the pre-cleaning step at the point of care. What is the BEST corrective action?

Issue a verbal warning and continue operations
Notify the patient and repeat the procedure
Immediately terminate the technician
Document the event, retrain the technician, and investigate if any scopes were compromised (Correct answer)

Correct answer: Document the event, retrain the technician, and investigate if any scopes were compromised

A documented corrective action plan including retraining and scope review is the appropriate QA response to a procedural deviation.

Question 4: How should flexible endoscopes be positioned during vertical storage in a drying cabinet?

Laid flat on foam padding
Hanging vertically with all caps removed (Correct answer)
Submerged in alcohol solution
Coiled on a shelf

Correct answer: Hanging vertically with all caps removed

Vertical hanging with caps removed allows residual moisture to drain and air to circulate through all channels.

Question 5: Under FDA regulations, which classification applies to flexible endoscopes used for diagnostic procedures?

Class II medical device (Correct answer)
Class III medical device
Exempt from classification
Class I medical device

Correct answer: Class II medical device

Flexible endoscopes are generally classified as Class II medical devices under FDA regulations, subject to special controls.

Question 6: Which organization publishes the primary national guideline used in the US for endoscope reprocessing, including manual cleaning standards?

The Society for Gastrointestinal Endoscopy (ASGE) alone
SGNA (Society of Gastroenterology Nurses and Associates) and AORN jointly (Correct answer)
The American Medical Association (AMA)
The Environmental Protection Agency (EPA)

Correct answer: SGNA (Society of Gastroenterology Nurses and Associates) and AORN jointly

SGNA and AORN publish widely adopted guidelines for endoscope reprocessing in the US, and adherence to these is considered the standard of care.

Question 7: Which storage method creates the highest risk of endoscope recontamination?

Horizontal coiled storage in an enclosed, unventilated cabinet (Correct answer)
Hanging vertically in filtered air with coiled cord
Vertical hanging in a HEPA-filtered drying cabinet
Vertical hanging in a ventilated open cabinet

Correct answer: Horizontal coiled storage in an enclosed, unventilated cabinet

Horizontal coiled storage traps moisture in the bends, and unventilated conditions promote microbial growth, creating high contamination risk.

Question 8: Which component of an AER is most susceptible to biofilm formation and requires routine preventive maintenance?

Internal water lines, reservoirs, and spray nozzles (Correct answer)
The exterior stainless steel cabinet
The digital control panel
The external door gasket

Correct answer: Internal water lines, reservoirs, and spray nozzles

Internal water lines, reservoirs, and spray nozzles create warm, moist environments ideal for biofilm growth, making them the highest priority for scheduled disinfection and flushing.

Question 9: What is an 'endoscope reprocessing log' and what information must it contain?

A log of how many patients had procedures
A maintenance log for the AER equipment
Only a record of chemical purchases
A record documenting each reprocessing cycle with scope ID, patient ID, technician, chemical details, test results, and date/time (Correct answer)

Correct answer: A record documenting each reprocessing cycle with scope ID, patient ID, technician, chemical details, test results, and date/time

The reprocessing log is the primary documentation of reprocessing events, linking each scope cycle to specific chemical, concentration, personnel, and patient data.

Question 10: When should the detergent solution used for manual cleaning be changed during a reprocessing session?

Never — the enzymatic action self-cleans the solution
Every 10 scopes regardless of appearance
According to manufacturer IFU, or when visibly soiled/turbid (Correct answer)
Only at the end of the shift

Correct answer: According to manufacturer IFU, or when visibly soiled/turbid

Detergent solutions become contaminated with organic matter and lose efficacy; they must be changed per manufacturer instructions or when visibly soiled.

Question 11: A new brand of enzymatic detergent is introduced to the reprocessing suite. What documentation update is REQUIRED before use?

Update the supply order form only
Post the MSDS sheet on the break room bulletin board
Notify the purchasing department
Revise the SOP to reflect the new product's dilution ratios, contact time, and compatibility with scopes (Correct answer)

Correct answer: Revise the SOP to reflect the new product's dilution ratios, contact time, and compatibility with scopes

Any new reprocessing product requires SOP revision to incorporate the manufacturer's specific use instructions before staff can use it.

Question 12: Which organization specifically certifies endoscope reprocessing professionals through the CER credential?

The Joint Commission
APIC (Association for Professionals in Infection Control)
CBSPD (Certification Board for Sterile Processing and Distribution)
IAHCSMM (International Association of Healthcare Central Service Materiel Management) (Correct answer)

Correct answer: IAHCSMM (International Association of Healthcare Central Service Materiel Management)

IAHCSMM administers the Certified Endoscope Reprocessor (CER) certification examination for endoscope reprocessing professionals.

Question 13: Which of the following microorganisms is used as the biological indicator (BI) for validating ETO (ethylene oxide) sterilization?

Geobacillus stearothermophilus
Mycobacterium terrae
Bacillus atrophaeus (subtilis) (Correct answer)
Staphylococcus aureus

Correct answer: Bacillus atrophaeus (subtilis)

Bacillus atrophaeus (formerly B. subtilis) spores are the standard biological indicator for ETO sterilization validation due to their high resistance to this agent.

Question 14: Why must all channels of a flexible endoscope be flushed with the cleaning solution during manual reprocessing?

To check for blockages only
To warm the scope before disinfection
Because biofilm and debris accumulate inside channels that are inaccessible by brushing alone (Correct answer)
To measure channel diameter compliance

Correct answer: Because biofilm and debris accumulate inside channels that are inaccessible by brushing alone

Internal lumens harbor organic material that brushes cannot fully reach; flushing ensures detergent contacts all surfaces to loosen and remove contamination.

Question 15: What should be done with single-use cleaning brushes after reprocessing an endoscope?

Discard after each use (Correct answer)
Sterilize and reuse up to 10 times
Soak in enzymatic solution for 30 minutes then reuse
Autoclave between uses

Correct answer: Discard after each use

Single-use cleaning brushes must be discarded after each use to prevent cross-contamination between patients.

Question 16: What is the purpose of rinsing an endoscope thoroughly with sterile or filtered water after HLD?

To lower the surface temperature before storage
To rehydrate the scope's internal channels
To activate antimicrobial properties of the scope materials
To remove residual disinfectant that could harm patients (Correct answer)

Correct answer: To remove residual disinfectant that could harm patients

Residual HLD chemicals can cause mucosal injury in patients, so thorough rinsing with sterile or filtered water after HLD is essential.

Question 17: What action should be taken if the endoscope fails the leak test?

Perform a second leak test only
Proceed with reprocessing and notify the manufacturer after the procedure
Remove the scope from service and send for repair before further use (Correct answer)
Increase the HLD contact time to compensate

Correct answer: Remove the scope from service and send for repair before further use

A scope that fails the leak test must be removed from service immediately and sent for repair to prevent patient harm and further instrument damage.

Question 18: What type of cabinet is considered the gold standard for endoscope drying and storage?

Refrigerated storage cabinet
Forced-air drying cabinet with HEPA filtration (Correct answer)
Standard stainless steel storage cabinet
Negative-pressure isolation cabinet

Correct answer: Forced-air drying cabinet with HEPA filtration

HEPA-filtered, forced-air drying cabinets continuously circulate clean, filtered air to maintain dry conditions and prevent recontamination.

Question 19: During inspection, the endoscope's air/water nozzle is found to be missing. What should the reprocessor do?

Notify the charge nurse but continue reprocessing
Replace the nozzle from a parts bin before reprocessing
Remove the scope from service; a missing nozzle prevents proper lens washing (Correct answer)
Reprocess the scope and return it to service — the nozzle is cosmetic only

Correct answer: Remove the scope from service; a missing nozzle prevents proper lens washing

The air/water nozzle is required for adequate lens washing during procedures; a missing nozzle renders the scope non-functional and it must be removed from service.

Question 20: Which type of brush is recommended for cleaning the instrument channel of a flexible endoscope?

Any stiff-bristle brush available in the department
A brush that is 10% larger than the channel diameter
A brush sized exactly to the channel diameter per manufacturer instructions (Correct answer)
A brush that is 50% smaller than the channel diameter for flexibility

Correct answer: A brush sized exactly to the channel diameter per manufacturer instructions

Brushes must match the channel diameter as specified by the endoscope manufacturer to ensure effective contact with channel walls without causing damage.

Question 21: An endoscope has been stored properly for 5 days. Before patient use, what step is required according to most facility protocols?

High-level disinfection only
Full reprocessing cycle (Correct answer)
Visual inspection only
Leak testing only

Correct answer: Full reprocessing cycle

Most facilities require full reprocessing of stored endoscopes after a defined maximum storage time (commonly 5–7 days) to ensure safety.

Question 22: After reprocessing, a technician performs a final visual inspection and finds water droplets inside the objective lens of a colonoscope. What does this indicate?

Fluid ingress through a breach in the distal optics, indicating scope damage (Correct answer)
Excessive irrigation during the procedure
Normal condensation from temperature differences during drying
Inadequate drying time in storage

Correct answer: Fluid ingress through a breach in the distal optics, indicating scope damage

Moisture inside the objective lens indicates that fluid has breached the optical seal, which is a sign of scope damage requiring removal from service and repair.

Question 23: What is the primary function of an enzymatic detergent during the manual cleaning of a flexible endoscope?

To lubricate the channels, making brush passage easier.
To kill microorganisms on the endoscope's surface.
To break down complex organic materials like blood, fat, and protein. (Correct answer)
To serve as a high-level disinfectant for internal channels.

Correct answer: To break down complex organic materials like blood, fat, and protein.

Enzymatic detergents contain enzymes such as proteases, lipases, and amylases that specifically target and break down organic soils (proteins, fats, carbohydrates) into smaller, water-soluble particles, making them easier to remove during cleaning. They are cleaners, not disinfectants, and while they reduce bioburden, their primary role is not to kill microorganisms but to remove the soil that harbors them.

Question 24: Which of the following is NOT a factor that can reduce the efficacy of a high-level disinfectant?

Organic soil remaining on the scope
Dilution from wet scopes
Elevated temperature beyond recommended range
Using a covered container during soak (Correct answer)

Correct answer: Using a covered container during soak

Using a covered container actually helps maintain concentration and temperature; it does not reduce HLD efficacy.

Question 25: Which component of a flexible endoscope is most frequently identified as a source of reprocessing failures and subsequent patient infections?

The control body buttons
The light guide connector
The outer insertion tube
The elevator mechanism of duodenoscopes (Correct answer)

Correct answer: The elevator mechanism of duodenoscopes

The elevator mechanism (forceps elevator) of duodenoscopes has a complex, difficult-to-clean design that has been linked to multiple outbreaks of carbapenem-resistant organism transmission.

Question 26: What is the correct disposal method for enzymatic cleaning solution after it has been used to clean an endoscope?

Discard after each use as enzymatic solutions are single-use (Correct answer)
Neutralize with bleach then dispose down the drain
Filter and reuse for non-patient-care equipment only
Reuse the solution for up to 24 hours to reduce waste

Correct answer: Discard after each use as enzymatic solutions are single-use

Enzymatic cleaning solutions are single-use and must be discarded after each endoscope cleaning because reused solution becomes saturated with organic material and loses effectiveness.

Question 27: A reprocessing technician moves a soiled endoscope from the procedure room to the decontamination area. Which transport container is most appropriate?

Any container is acceptable if the technician wears gloves
An open tray carried at arm's length
A standard pillowcase tied at the top
A leak-proof, labeled, closed container (Correct answer)

Correct answer: A leak-proof, labeled, closed container

Soiled endoscopes must be transported in a closed, leak-proof, labeled container to prevent staff exposure and environmental contamination.

Question 28: Which liquid chemical sterilant system uses peracetic acid as its active ingredient to achieve sterilization of flexible endoscopes?

STERRAD NX (ASP)
Metricide 28 (glutaraldehyde)
Cidex OPA (ortho-phthalaldehyde)
STERIS System 1E (Correct answer)

Correct answer: STERIS System 1E

The STERIS System 1E uses peracetic acid as the active sterilant and provides liquid chemical sterilization for heat-sensitive flexible endoscopes at the point of use.

Question 29: Which component of an endoscope requires special attention during leak testing before manual cleaning?

The insertion tube and bending section (Correct answer)
The control body handle grips
The light guide connector
The eyepiece lens

Correct answer: The insertion tube and bending section

The insertion tube and bending section are most vulnerable to perforations and must be carefully inspected during leak testing before immersion.

Question 30: What information is LEAST likely to be required on a standard endoscope reprocessing log?

Disinfectant lot number and expiration date
Scope serial number
Technician ID or initials
Patient name or procedure room number (Correct answer)

Correct answer: Patient name or procedure room number

Reprocessing logs track the scope and chemicals, not patient-identifying information, which is stored in procedure records.

Question 31: When performing channel brushing during manual cleaning, how many passes should the brush make through each channel?

One pass is sufficient if bristles contact all surfaces
Exactly three passes regardless of soiling level
Until the brush exits clean with no visible debris (Correct answer)
Two passes in each direction (four total)

Correct answer: Until the brush exits clean with no visible debris

Brushing should continue until the brush exits visibly clean, as the number of passes needed varies with the degree of soiling.

Question 32: When should the reprocessing area be terminally cleaned and disinfected?

Once per week
Only when visibly soiled
At minimum at the end of each day, with more frequent cleaning of high-touch surfaces between reprocessing sessions (Correct answer)
Only when directed by infection control

Correct answer: At minimum at the end of each day, with more frequent cleaning of high-touch surfaces between reprocessing sessions

Daily terminal cleaning removes accumulated contamination from all surfaces; high-touch surfaces should be disinfected more frequently during active reprocessing.

Question 33: What is the purpose of angulating the endoscope in all four directions during the leak test?

To expose the bending section in different positions, revealing leaks that may only manifest under stress (Correct answer)
To test the flexibility of the angulation wires
To lubricate the angulation mechanism
To verify the scope is not kinked

Correct answer: To expose the bending section in different positions, revealing leaks that may only manifest under stress

Different angulation positions stretch different parts of the bending section, revealing small leaks that may not be visible with the scope in the neutral position.

Question 34: A detergent manufacturer's IFU specifies a dilution ratio of 1:100. If you are preparing 2 liters of solution, how much detergent concentrate is required?

100 mL
10 mL
20 mL (Correct answer)
50 mL

Correct answer: 20 mL

1:100 means 1 part concentrate per 100 parts total solution; 2000 mL ÷ 100 = 20 mL of concentrate.

Question 35: What is the significance of 'biofilm' in endoscope reprocessing?

A protective coating applied during manufacturing
Residue left by enzymatic cleaners
A community of microorganisms encased in a matrix that resists standard disinfection (Correct answer)
Mineral deposits from hard water

Correct answer: A community of microorganisms encased in a matrix that resists standard disinfection

Biofilm is a microbial community that adheres to surfaces and is highly resistant to disinfectants, making thorough mechanical cleaning critical.

Question 36: When performing a leak test on a videoscope, the endoscope must be tested:

Only after high-level disinfection is completed
Submerged with the water-resistant cap removed
After enzymatic soaking to ensure channels are patent
Dry, before any contact with water or cleaning solution (Correct answer)

Correct answer: Dry, before any contact with water or cleaning solution

The leak test must be performed on a dry scope before immersion to detect existing damage before fluids can enter and worsen internal damage.

Question 37: What is the purpose of the drying phase at the end of an AER cycle?

To remove residual moisture and prevent microbial growth during storage (Correct answer)
To sterilize the endoscope using heat
To neutralize chemical disinfectant residue
To cool the endoscope before handling

Correct answer: To remove residual moisture and prevent microbial growth during storage

The drying phase removes residual moisture from channels and surfaces to inhibit microbial growth during storage between uses.

Question 38: In EO sterilization, which factor does NOT directly affect sterilization efficacy?

Relative humidity during the cycle
Color of the packaging material (Correct answer)
Temperature of the sterilization chamber
EO gas concentration

Correct answer: Color of the packaging material

The color of packaging material has no bearing on sterilization efficacy; the critical parameters are EO concentration, humidity, temperature, and exposure time.

Question 39: What risk does inadequate drying of endoscope channels before storage pose?

Degradation of the endoscope's optical fibers
Increased risk of electrical shorts during the next procedure
Accelerated corrosion of the light guide connectors
Proliferation of waterborne microorganisms and biofilm formation (Correct answer)

Correct answer: Proliferation of waterborne microorganisms and biofilm formation

Residual moisture in channels provides a favorable environment for waterborne microorganisms like Pseudomonas aeruginosa to multiply and form biofilm before the next patient use.

Question 40: Which endoscope channel accumulates the greatest organic burden during a procedure and poses the highest reprocessing contamination risk?

Light guide channel
Water jet channel
Working (biopsy/suction) channel (Correct answer)
Air insufflation channel

Correct answer: Working (biopsy/suction) channel

The working channel contacts blood, mucus, tissue, and accessories directly, making it the primary source of organic load and biofilm risk.

Question 41: Which of the following is a key reason why floors in the decontamination area should be seamless or have minimal grout lines?

Seams and grout harbor microorganisms and make effective cleaning difficult (Correct answer)
Seamless floors are required by OSHA for slip-resistance certification
Seamless floors reduce noise levels during high-volume reprocessing
Grout lines interfere with the drainage requirements of AER machines

Correct answer: Seams and grout harbor microorganisms and make effective cleaning difficult

Seams and porous grout lines can harbor pathogens and biofilm that are difficult to remove with standard disinfection methods.

Question 42: What minimum records must be documented for each sterilization cycle per regulatory and accreditation standards?

Chemical indicator result and sterilizer model number only
Biological indicator result only
Cycle number, date, load contents, operator identification, and monitoring results (Correct answer)
Patient name and procedure type associated with sterilized items

Correct answer: Cycle number, date, load contents, operator identification, and monitoring results

Complete cycle documentation enables traceability for recalls and must include cycle number, date and time, load contents, operator ID, and results of all monitoring (chemical and biological).

Question 43: What is the function of the air/water channel in a flexible endoscope?

To aspirate fluid and tissue samples from the patient
To deliver medications to the patient
To insufflate air into the lumen and flush the lens with water for visualization (Correct answer)
To circulate coolant to the light source

Correct answer: To insufflate air into the lumen and flush the lens with water for visualization

The air/water channel delivers air to distend the lumen for visualization and water to clean the lens at the distal tip.

Question 44: When using a pressure manometer during leak testing, the pressure gauge should be read after:

Activating the leak tester but before attaching to the scope
Pressurizing to the specified range and stabilizing for 30 seconds, then submerging (Correct answer)
Completing submersion and waiting 10 minutes
Immediately pressurizing the scope before submerging

Correct answer: Pressurizing to the specified range and stabilizing for 30 seconds, then submerging

Pressure must be allowed to stabilize before submerging so the baseline is established, then any subsequent drop indicates a leak.

Question 45: What does 'scope tracking' software primarily help endoscope reprocessing departments accomplish?

Schedule patient procedure appointments
Train new reprocessing technicians on procedures
Link each scope to its reprocessing cycle history, use history, and storage location in real time (Correct answer)
Calculate departmental supply budgets

Correct answer: Link each scope to its reprocessing cycle history, use history, and storage location in real time

Scope tracking software creates an auditable record tying each device to its full cycle of use, reprocessing, and storage for traceability.

Question 46: Which type of hepatitis virus is classified as MOST resistant to chemical inactivation?

Hepatitis C
Hepatitis D
Hepatitis A
Hepatitis B (Correct answer)

Correct answer: Hepatitis B

Hepatitis B virus is notably more resistant to chemical disinfectants than Hepatitis A, C, or D, requiring high-level disinfection for reliable inactivation.

Question 47: Which of the following best describes a 'corrective action plan' in the context of endoscope reprocessing QA?

A list of approved chemical disinfectants
A training program for new reprocessing technicians
A schedule for replacing aging endoscopes
A documented response to a reprocessing failure that identifies root cause and prevents recurrence (Correct answer)

Correct answer: A documented response to a reprocessing failure that identifies root cause and prevents recurrence

A corrective action plan formally documents the root cause of a reprocessing failure and the steps taken to prevent it from recurring.

Question 48: A technician notices that the minimum effective concentration (MEC) test strip result is below the required threshold for the glutaraldehyde solution in use. What is the correct action?

Continue using the solution until the expiration date
Add more glutaraldehyde concentrate to raise concentration
Extend immersion time to compensate
Discard the solution and prepare a fresh batch (Correct answer)

Correct answer: Discard the solution and prepare a fresh batch

When MEC testing shows the disinfectant is below effective concentration, it must be discarded immediately and replaced with fresh solution — there is no approved remediation.

Question 49: What is the purpose of flushing all channels with enzymatic solution during manual cleaning?

To remove residual lubricant from the previous procedure
To sterilize the internal lumens
To test for leaks before high-level disinfection
To ensure enzymatic solution contacts all internal surfaces for effective soil removal (Correct answer)

Correct answer: To ensure enzymatic solution contacts all internal surfaces for effective soil removal

Flushing channels with enzymatic solution ensures the cleaning agent reaches all internal surfaces to break down organic soil prior to brushing.

Question 50: According to ANSI/AAMI ST91, what is the recommended practice for endoscopes that have been processed using a liquid chemical sterilization (LCS) system but are not intended for immediate use?

They must be dried with 70% isopropyl alcohol and then packaged in a sterile container.
They can be stored with a claim of being sterile for up to 7 days.
They should be used immediately, as storage is not recommended for liquid chemically sterilized items.
They can be stored in the same manner as endoscopes that have undergone high-level disinfection. (Correct answer)

Correct answer: They can be stored in the same manner as endoscopes that have undergone high-level disinfection.

ANSI/AAMI ST91 states that liquid chemically sterilized endoscopes intended for critical procedures should be used immediately. If not for immediate use, they can be stored in the same way as endoscopes that have undergone high-level disinfection (HLD), which involves thorough drying and storage in a clean, dedicated cabinet. They should not be stored with a claim of being patient-ready sterile.

Question 51: What is the difference between a chemical indicator (CI) and a biological indicator (BI)?

CIs confirm sterility; BIs only monitor temperature
CIs test for chemical concentration; BIs test temperature only
BIs are cheaper and used more frequently than CIs
CIs change color in response to sterilization parameters (time/temperature/chemical); BIs use live spores to confirm lethality (Correct answer)

Correct answer: CIs change color in response to sterilization parameters (time/temperature/chemical); BIs use live spores to confirm lethality

Chemical indicators respond to physical/chemical sterilization parameters while biological indicators directly challenge lethality using resistant organisms.

Question 52: A facility's automated endoscope reprocessor (AER) completes a high-level disinfection cycle. Which of the following is the most critical next step to prevent recontamination of the endoscope before storage?

A final rinse with unfiltered tap water.
Thorough rinsing with sterile or filtered water, followed by an alcohol flush and forced air drying. (Correct answer)
Wiping the exterior with a sterile gauze.
Immediate placement in a non-ventilated cabinet.

Correct answer: Thorough rinsing with sterile or filtered water, followed by an alcohol flush and forced air drying.

After HLD, endoscopes must be thoroughly rinsed with sterile or bacteria-free water (e.g., passed through a 0.2-micron filter) to remove toxic disinfectant residue. This is followed by flushing channels with 70% alcohol to aid in drying and then purging all channels with forced, filtered air until visibly dry. Inadequate rinsing can cause patient injury, and inadequate drying can allow remaining waterborne microorganisms to proliferate.

Question 53: An endoscope used for a bronchoscopy procedure is classified under the Spaulding system as:

Critical, requiring sterilization only
Semi-critical, requiring at minimum high-level disinfection (Correct answer)
Non-critical, requiring low-level disinfection
Non-critical, requiring intermediate-level disinfection

Correct answer: Semi-critical, requiring at minimum high-level disinfection

Bronchoscopes contact mucous membranes and are classified as semi-critical devices requiring a minimum of high-level disinfection between patient uses.

Question 54: What is the maximum water temperature recommended during manual cleaning of flexible endoscopes to prevent protein coagulation?

Hot water (up to 60°C)
Warm water (up to 45°C)
Cold water only (below 10°C)
Lukewarm water (up to 35°C) (Correct answer)

Correct answer: Lukewarm water (up to 35°C)

Lukewarm water up to 35°C is recommended because hot water can coagulate proteins, making bioburden harder to remove.

Question 55: What does the term 'biofilm' refer to in the context of endoscope reprocessing?

A protective coating applied to endoscope surfaces during manufacturing
A community of microorganisms embedded in a self-produced matrix that adheres to surfaces (Correct answer)
A sterile barrier membrane used during high-level disinfection
The thin film of detergent left after inadequate rinsing

Correct answer: A community of microorganisms embedded in a self-produced matrix that adheres to surfaces

Biofilm is a complex community of bacteria encased in a polysaccharide matrix that adheres to channel walls and is highly resistant to disinfectants, making thorough manual cleaning essential to disrupt it.

Question 56: What is the primary purpose of conducting routine microbiological surveillance testing on reprocessed endoscopes and automated endoscope reprocessors (AERs)?

To verify the sterility of every endoscope before patient use.
To identify the specific brand of cleaning detergent that works best.
To act as a quality control measure to verify the overall effectiveness of the reprocessing protocol. (Correct answer)
To determine the endoscope's remaining useful life before it needs replacement.

Correct answer: To act as a quality control measure to verify the overall effectiveness of the reprocessing protocol.

Microbiological surveillance is a quality control tool used to periodically verify that reprocessing procedures (both manual and automated) are consistently effective at producing a safe, patient-ready endoscope. It is not intended to clear each scope for use but rather to detect potential process failures, equipment issues, or lapses in practice over time.

Question 57: After sterilization using the STERIS System 1E, endoscopes must be:

Rinsed with tap water before use
Used immediately or stored in sterile packaging (Correct answer)
Stored dry in a sealed container for up to 30 days
Re-packaged and resterilized if not used within 24 hours

Correct answer: Used immediately or stored in sterile packaging

Because the STERIS System 1E provides point-of-use sterilization without a sterile packaging system, items must be used immediately after processing.

Question 58: What is the correct sequence of manual cleaning steps for a flexible endoscope?

Wipe exterior → enzymatic soak → brush → rinse → leak test
Point-of-use pre-cleaning → leak test → enzymatic soak/brushing → thorough rinse (Correct answer)
Pre-cleaning → HLD → rinse → enzymatic soak → brush
Leak test → rinse → brush → enzymatic soak → final rinse

Correct answer: Point-of-use pre-cleaning → leak test → enzymatic soak/brushing → thorough rinse

The correct sequence begins with point-of-use pre-cleaning, followed by leak testing, then enzymatic soaking and brushing, and finally thorough rinsing before high-level disinfection.

Question 59: A facility conducts an unannounced audit and finds reprocessing logs missing for 12 scopes processed the previous day. This MOST likely indicates:

An IT system error that will self-correct
A minor clerical oversight with no patient safety implications
That the log printer was broken
A potential patient safety incident requiring scope quarantine and notification of infection control (Correct answer)

Correct answer: A potential patient safety incident requiring scope quarantine and notification of infection control

Missing logs for processed scopes mean reprocessing cannot be verified, requiring quarantine and infection control investigation as a patient safety matter.

Question 60: Which organization sets national guidelines specifically addressing endoscope reprocessing and HLD in the United States?

The FDA, through 510(k) clearance of scopes
OSHA, through the Bloodborne Pathogens Standard only
The Joint Commission, through accreditation surveys only
CDC and AAMI, through guidelines such as ST91 (Correct answer)

Correct answer: CDC and AAMI, through guidelines such as ST91

The CDC and AAMI (through standard ST91) provide the primary national guidelines for endoscope reprocessing, including HLD procedures, in the United States.

Question 61: Which ANSI/AAMI standard provides requirements for steam sterilization used on endoscope components that are heat-stable?

ANSI/AAMI TIR34
ANSI/AAMI ST79 (Correct answer)
ANSI/AAMI ST41
ANSI/AAMI ST58

Correct answer: ANSI/AAMI ST79

ANSI/AAMI ST79 is the comprehensive guide to steam sterilization and sterility assurance in health care facilities, applicable to heat-stable endoscope accessories.

Question 62: A biological indicator (BI) test of an AER shows growth after the cycle. What does this indicate?

The AER cycle may have failed to achieve adequate disinfection (Correct answer)
The endoscope channel was too narrow for the cycle
The BI was improperly stored and is a false positive
The chemical disinfectant is at an acceptable concentration

Correct answer: The AER cycle may have failed to achieve adequate disinfection

Growth in a BI after an AER cycle indicates the process may not have achieved the required level of microbial kill, necessitating investigation and remediation.

Question 63: A reprocessing department supervisor is preparing for an annual audit. To comply with quality assurance standards like AAMI ST91, what must each technician's competency assessment file include?

A copy of the technician's professional resume.
Documented evidence of initial orientation, direct observation of tasks, and annual performance reviews. (Correct answer)
A list of all endoscope models the technician has ever processed.
A record of the technician's attendance at general hospital staff meetings.

Correct answer: Documented evidence of initial orientation, direct observation of tasks, and annual performance reviews.

Quality assurance standards, such as AAMI ST91, require a formal process to ensure staff are competent to perform their duties. This includes documenting initial training, verifying skills through direct observation of critical tasks (like leak testing and manual cleaning), and conducting regular (at least annual) competency assessments to ensure skills are maintained.

Question 64: What is 'traceability' in the context of endoscope reprocessing quality assurance?

Tracking the location of endoscope storage cabinets
The ability to link each scope used on a patient to the complete reprocessing record for that cycle, including personnel, chemicals, and outcomes (Correct answer)
Recording the purchase history of endoscopes
Only relevant in outbreak situations

Correct answer: The ability to link each scope used on a patient to the complete reprocessing record for that cycle, including personnel, chemicals, and outcomes

Traceability is the documented connection between each patient procedure, the scope used, and every reprocessing event — enabling rapid investigation if infection occurs.

Question 65: What is the required minimum soak time for glutaraldehyde 2.4% to achieve high-level disinfection at 25°C (77°F)?

60 minutes
45 minutes (Correct answer)
10 minutes
20 minutes

Correct answer: 45 minutes

At 25°C, glutaraldehyde 2.4% requires a minimum 45-minute soak to achieve HLD per most manufacturer instructions for use.

Question 66: When performing leak testing on a flexible endoscope, a continuous stream of bubbles from the insertion tube indicates:

Normal air purging from the water channel
Successful pressure equalization
A breach in the external sheath requiring repair before reprocessing continues (Correct answer)
Over-inflation of the air supply tube

Correct answer: A breach in the external sheath requiring repair before reprocessing continues

Continuous bubbling from the insertion tube signals a perforation or defect in the sheath that would allow fluid ingress and damage internal components.

Question 67: Which of the following BEST represents a proactive QA approach to endoscope reprocessing?

Updating SOPs only when a new scope is purchased
Conducting scheduled mock audits, competency reviews, and trending quality indicators before problems arise (Correct answer)
Investigating failures only after a patient infection is reported
Relying solely on AER alarms to flag reprocessing failures

Correct answer: Conducting scheduled mock audits, competency reviews, and trending quality indicators before problems arise

Proactive QA uses scheduled audits, trending, and competency checks to identify and correct vulnerabilities before patient harm occurs.

Question 68: Which class of chemical indicator is considered the most comprehensive, responding to all critical sterilization parameters for a specific cycle type?

Class 6 — emulating indicators (Correct answer)
Class 5 — integrating indicators
Class 1 — process indicators (exposure indicators)
Class 3 — single-variable indicators

Correct answer: Class 6 — emulating indicators

Class 6 emulating indicators are cycle-specific and react to all critical parameters (time, temperature, sterilant concentration) calibrated to a specific sterilization cycle.

Question 69: Which of the following materials is most appropriate for work surfaces in the decontamination area due to chemical and moisture resistance?

Stainless steel or solid-surface non-porous material (Correct answer)
Untreated wood laminate
Porous concrete
Standard painted drywall

Correct answer: Stainless steel or solid-surface non-porous material

Stainless steel and solid-surface non-porous materials resist the corrosive disinfectants used in decontamination and are easy to clean and disinfect.

Question 70: In a video endoscope, where is the image sensor (CCD or CMOS chip) located?

At the distal tip of the insertion tube (Correct answer)
Inside the universal cord connector
Inside the external video processor
Inside the control body housing

Correct answer: At the distal tip of the insertion tube

The image sensor is embedded in the distal tip to capture high-resolution images directly at the procedure site and transmit signals proximally.

Question 71: What is the purpose of bending the insertion tube in all four directions during the functional inspection?

To clear debris from angulation wires
To confirm light transmission through the fiber bundle
To check the water-jet channel for blockages
To verify angulation wire and control wheel integrity (Correct answer)

Correct answer: To verify angulation wire and control wheel integrity

Flexing in all directions tests the angulation wires, control wheels, and bending section for damage that may restrict full tip deflection.

Question 72: Which component of the endoscope reprocessing environment presents the greatest ongoing biofilm contamination risk if not properly controlled?

Storage cabinet shelving
Automated endoscope reprocessor (AER) interior (Correct answer)
Transport container lids
Personal protective equipment

Correct answer: Automated endoscope reprocessor (AER) interior

The interior chambers and tubing of AERs can harbor biofilm if not regularly cleaned, tested, and maintained, potentially recontaminating processed endoscopes.

Question 73: What is the primary function of O-rings located at endoscope channel port openings?

To stabilize angulation wire tension
To create a watertight seal preventing fluid ingress during immersion (Correct answer)
To attach the universal cord to the control body
To anchor the light guide fiber bundle

Correct answer: To create a watertight seal preventing fluid ingress during immersion

O-rings form a watertight seal at channel openings to prevent disinfectant or cleaning fluid from entering internal components during reprocessing.

Question 74: Why must reusable cleaning brushes be reprocessed between patients?

To maintain bristle stiffness
Because regulatory agencies require daily brush sterilization
To remove enzymatic cleaner residue that damages bristles
To prevent cross-contamination of microorganisms between patients (Correct answer)

Correct answer: To prevent cross-contamination of microorganisms between patients

Reusable brushes can harbor pathogens and must be thoroughly cleaned and reprocessed between each patient use to prevent cross-contamination.

Question 75: Which sterilization method uses peracetic acid as the active sterilant for heat-sensitive endoscopes?

STERIS System 1E (Correct answer)
STERRAD system
Ethylene oxide (EO)
Vaporized hydrogen peroxide (VHP)

Correct answer: STERIS System 1E

The STERIS System 1E uses liquid peracetic acid at approximately 50°C to sterilize heat-sensitive endoscopes.

Question 76: Which statement about enzymatic detergents used in endoscope cleaning is TRUE?

They are typically single-use and must be discarded after each scope or per manufacturer instructions (Correct answer)
A higher concentration always produces better cleaning results
They should be mixed with hot water to activate the enzymes more quickly
They can be reused throughout the day if they remain clear

Correct answer: They are typically single-use and must be discarded after each scope or per manufacturer instructions

Enzymatic detergent solutions are generally intended for single use or per manufacturer guidance because enzymes denature and lose activity after exposure to soil and time.

Question 77: Which of the following correctly describes a critical-use endoscope classification under the Spaulding classification scheme?

All flexible endoscopes regardless of site of use
Endoscopes that enter sterile tissue or the vascular system and require sterilization (Correct answer)
Endoscopes that contact intact mucous membranes and require high-level disinfection
Endoscopes used only on the skin surface requiring intermediate-level disinfection

Correct answer: Endoscopes that enter sterile tissue or the vascular system and require sterilization

Under Spaulding's classification, critical items contact sterile tissue or the bloodstream and must be sterilized; semi-critical items (most flexible endoscopes) contact mucous membranes and require minimum high-level disinfection.

Question 78: What must be done to an endoscope that has been stored beyond the facility's established hang time?

Soak in 70% isopropyl alcohol for 5 minutes
Wipe the exterior with alcohol and use immediately
Reprocess fully before use (Correct answer)
Perform only a distal-tip inspection before use

Correct answer: Reprocess fully before use

An endoscope that has exceeded its storage hang time must undergo full reprocessing before patient use.

Question 79: When should endoscopes stored on open pegs or hooks without a cabinet be considered for reprocessing?

Never — open storage maintains sterility better than cabinets
Per facility policy, but typically within 24–48 hours for unsupported open storage (Correct answer)
After 30 days
After 7 days regardless of conditions

Correct answer: Per facility policy, but typically within 24–48 hours for unsupported open storage

Open storage without filtered airflow or contamination protection requires shorter hang times, typically 24–48 hours, before reprocessing.

Question 80: When transporting a reprocessed endoscope to a storage area, which action best prevents recontamination?

Carrying the scope by hand in a sterile gloved hand
Using a dedicated clean transport container or cart separate from dirty transport (Correct answer)
Wrapping the scope in a sterile drape
Using the same cart used to bring the dirty scope from the procedure room

Correct answer: Using a dedicated clean transport container or cart separate from dirty transport

Reprocessed endoscopes must be transported on clean, dedicated equipment separated from dirty transport pathways to prevent recontamination.

Question 81: Which regulatory body has the authority to issue a 483 Observation or Warning Letter to an endoscope reprocessing facility?

CMS
FDA (Correct answer)
The Joint Commission
OSHA

Correct answer: FDA

FDA Form 483 Observations and Warning Letters are issued by the FDA following inspections that identify deviations from current Good Manufacturing Practices or device regulations.

Question 82: What does 'bioburden' refer to in the context of endoscope decontamination?

The total number of viable microorganisms on the endoscope before reprocessing (Correct answer)
The weight of biological tissue collected during a procedure
The degree of wear on the endoscope's insertion tube
The chemical load left by cleaning agents

Correct answer: The total number of viable microorganisms on the endoscope before reprocessing

Bioburden is the quantitative measure of viable microorganisms present on or in the endoscope that must be reduced through proper cleaning and disinfection.

Question 83: Which water temperature is generally recommended for mixing enzymatic cleaning solutions for endoscopes?

Lukewarm water per manufacturer specifications, typically 20–35°C (Correct answer)
Cold water below 15°C to prevent protein coagulation
Boiling water to activate enzymes faster
Distilled water at exactly 40°C regardless of manufacturer guidance

Correct answer: Lukewarm water per manufacturer specifications, typically 20–35°C

Lukewarm water within the manufacturer's specified temperature range optimizes enzymatic activity without denaturing the enzymes.

Question 84: A gastroscope used on a patient with active tuberculosis requires which level of reprocessing?

Immediate disposal as single-use equipment
High-level disinfection following standard reprocessing protocol (Correct answer)
Low-level disinfection with 70% alcohol
Standard precaution cleaning only

Correct answer: High-level disinfection following standard reprocessing protocol

Mycobacterium tuberculosis is susceptible to high-level disinfectants, so standard HLD reprocessing protocol is appropriate and sufficient for this organism.

Question 85: When should a flexible endoscope undergo preventive maintenance by a qualified repair technician?

Once every five years regardless of use frequency
According to the manufacturer's recommended schedule and after any suspected damage (Correct answer)
Only after a documented patient complaint is received
Only when a visible defect is apparent to the user

Correct answer: According to the manufacturer's recommended schedule and after any suspected damage

Scheduled preventive maintenance and post-incident inspections ensure optimal performance and early detection of defects before patient harm occurs.

Question 86: During manual cleaning in the decontamination area, why should the endoscope be submerged below the waterline when flushing channels?

It keeps the enzymatic solution warmer and more active during cleaning
Submersion is optional and only done for scopes with visible blood contamination
Submersion prevents aerosol and splatter generation that could contaminate the environment and staff (Correct answer)
Regulatory standards require submersion only for bronchoscopes, not GI scopes

Correct answer: Submersion prevents aerosol and splatter generation that could contaminate the environment and staff

Cleaning channels while the scope is submerged prevents the generation of aerosols containing potentially infectious material, protecting reprocessing staff and the environment.

Question 87: A storage cabinet for high-level disinfected endoscopes must NOT be located near which of the following?

The scheduling desk for endoscopy appointments
The supply room where sterile single-use accessories are stored
The nursing station medication room
Soiled utility rooms, reprocessing sinks, or areas where dirty items are handled (Correct answer)

Correct answer: Soiled utility rooms, reprocessing sinks, or areas where dirty items are handled

Proximity to soiled utility areas or reprocessing sinks creates risk of aerosolization and cross-contamination of reprocessed scopes from dirty items.

Question 88: During manual cleaning, how should elevator channels found on duodenoscopes be treated?

Elevator channels should be bypassed and cleaned via automated reprocessors only
They do not require brushing as they are self-cleaning
They should be cleaned using standard biopsy channel brushes only
They require special brushes and detailed cleaning per manufacturer IFU due to their complex design (Correct answer)

Correct answer: They require special brushes and detailed cleaning per manufacturer IFU due to their complex design

Duodenoscope elevator mechanisms have complex recessed areas that harbor bioburden and require specific cleaning tools and detailed manual cleaning steps per manufacturer IFU.

Question 89: Which factor MOST directly determines whether an organism is classified as a 'high-level disinfection-resistant' pathogen?

Its gram-negative cell wall composition
The presence of a lipid envelope protecting the cell membrane
Its ability to produce exotoxins that inactivate disinfectants
Its ability to form spores or highly resistant cellular structures (Correct answer)

Correct answer: Its ability to form spores or highly resistant cellular structures

Spore formation (e.g., bacterial endospores) confers extreme resistance to chemical disinfectants, placing spore-formers beyond the kill range of HLD agents.

Question 90: Which of the following is a method used to biochemically verify the adequacy of the manual cleaning process by detecting residual organic material before high-level disinfection?

Dry leak testing.
Adenosine Triphosphate (ATP) testing. (Correct answer)
Microbiological culturing.
Borescope visual inspection.

Correct answer: Adenosine Triphosphate (ATP) testing.

Adenosine Triphosphate (ATP) testing is a rapid method used to verify cleaning effectiveness. ATP is a molecule found in all living cells and organic matter; its presence indicates that residual bioburden may be present after cleaning. While borescopes provide enhanced visual inspection and cultures check for live microbes, ATP tests provide a quick, biochemical measure of overall organic soil removal.

Question 91: Which action must be taken immediately after a flexible endoscope is removed from a patient?

Cap all channels and send to sterile processing
Wipe the insertion tube and flush channels with detergent water at point of use (Correct answer)
Soak in glutaraldehyde for 20 minutes
Place directly in the AER

Correct answer: Wipe the insertion tube and flush channels with detergent water at point of use

Point-of-use pre-cleaning prevents soil from drying in channels, making subsequent cleaning more effective.

Question 92: How many times should a channel brush be passed through an endoscope channel during manual cleaning?

Once in each direction
Until the brush emerges visibly clean (Correct answer)
Exactly three times regardless of soil level
Ten times minimum per SGNA guidelines

Correct answer: Until the brush emerges visibly clean

Brushing should continue until the brush emerges free of visible soil, ensuring thorough removal of debris from the channel.

Question 93: A facility's QA data shows a repeated spike in ATP test failures on Monday mornings. The MOST likely explanation is:

Monday staff are less experienced
ATP strips expire on weekends
Endoscopes stored over the weekend may have biofilm accumulation or reprocessing was rushed before Monday cases (Correct answer)
ATP machines malfunction in cold storage rooms

Correct answer: Endoscopes stored over the weekend may have biofilm accumulation or reprocessing was rushed before Monday cases

Scopes stored over the weekend can develop biofilm, and post-storage reprocessing may be incomplete, explaining Monday morning ATP failures.

Question 94: Which area of the body is a gastroscope designed to view?

Brain
Lungs
Stomach (Correct answer)
Intestines

Correct answer: Stomach

Explanation: <br> A gastroscope is a flexible endoscope specifically designed to view the interior of the stomach. It is used for diagnostic and therapeutic procedures to examine the lining of the stomach for abnormalities, such as ulcers, tumors, or inflammation.

Question 95: What does a 'four-way angulation' tip deflection capability mean for an endoscope?

There are four separate bending sections in the insertion tube
The tip can be deflected in up, down, left, and right directions (Correct answer)
The tip can only move up and down
The scope has four angulation knobs

Correct answer: The tip can be deflected in up, down, left, and right directions

Four-way angulation means the distal tip can be deflected in all four directions (up/down and left/right), providing full maneuverability within body cavities.

Question 96: According to the Spaulding Classification, flexible gastrointestinal endoscopes that contact mucous membranes are classified as:

Critical devices requiring high-level disinfection only
Semi-critical devices requiring at minimum high-level disinfection (Correct answer)
Non-critical devices requiring low-level disinfection
Critical devices requiring sterilization

Correct answer: Semi-critical devices requiring at minimum high-level disinfection

Flexible endoscopes are semi-critical devices per the Spaulding Classification because they contact intact mucous membranes and require at minimum high-level disinfection.

Question 97: What is the primary purpose of an Automated Endoscope Reprocessor (AER)?

To store cleaned endoscopes in a sterile environment
To automate the high-level disinfection and rinsing cycle for endoscopes (Correct answer)
To sterilize endoscopes using ethylene oxide gas
To perform manual brushing of endoscope channels

Correct answer: To automate the high-level disinfection and rinsing cycle for endoscopes

AERs automate the high-level disinfection and rinsing process, reducing manual steps and human error in endoscope reprocessing.

Question 98: What is the recommended practice for handling personal items (phones, food, drinks) in the decontamination area?

Personal items are allowed only during breaks when reprocessing is paused
Personal items are strictly prohibited in the decontamination area (Correct answer)
Food is prohibited but personal electronics are acceptable with a cover
Personal items are allowed if kept in a sealed bag

Correct answer: Personal items are strictly prohibited in the decontamination area

Personal items in the decontamination area risk becoming vectors for pathogen transmission to staff and outside environments and are strictly prohibited.

Question 99: Which property of hydrogen peroxide plasma sterilization makes it unsuitable for endoscopes with long, narrow lumens?

Inability to penetrate deep lumens due to diffusion limits (Correct answer)
Excessive temperature
Activation of residual organic material
Corrosive effect on stainless steel

Correct answer: Inability to penetrate deep lumens due to diffusion limits

Hydrogen peroxide plasma has diffusion limitations that prevent adequate penetration of long, narrow lumens common in flexible endoscopes.

Question 100: What is the required negative pressure differential for the soiled/decontamination zone of an endoscope reprocessing area?

Positive pressure — to push contaminants away from the area
Negative pressure relative to adjacent areas — to contain airborne contaminants within the decontamination zone (Correct answer)
Pressure depends on the number of procedures performed daily
Equal pressure to adjacent areas

Correct answer: Negative pressure relative to adjacent areas — to contain airborne contaminants within the decontamination zone

Negative pressure in the decontamination zone prevents airborne contaminants from migrating to adjacent clean areas.

Certified Endoscope Reprocessor (CER) Exam

The CER exam certifies professionals in the safe and effective reprocessing of flexible endoscopes, covering cleaning, disinfection, sterilization, and quality assurance procedures.

100

Questions

120 min

Time Limit

70%

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