22 Infection Prevention Practice Questions & Answers

1. 1. A technician argues that a tray from a patient with known hepatitis C should be processed differently from routine trays. What is the BEST response under standard precautions?

   • A.The tray requires a longer sterilization exposure time than normal
   • B.The tray should be soaked in a disinfectant before it enters the washer
   • C.The tray should be double-bagged and processed at the end of the shift
   • D.All soiled instruments are already handled as potentially infectious, so the process does not change based on diagnosis✓ Answer

   Standard precautions require treating all blood, body fluids, non-intact skin and mucous membranes as potentially infectious regardless of the patient's diagnosis. Because sterile processing already applies the maximum level of protection to every item, no diagnosis-driven upgrade exists; varying the process by diagnosis would also imply that unlabeled trays are being handled less safely, which is exactly what standard precautions were created to prevent.

   Source: CDC/HICPAC Standard Precautions; HSPA CRCST Content Outline Sec. 2.I.AReport a problem with this question

2. 2. Which action in the decontamination area MOST directly breaks the 'mode of transmission' link in the chain of infection?

   • A.Isolating an infected patient in a private room
   • B.Screening patients for infection before surgery is scheduled
   • C.Cleaning contaminated instruments so they cannot carry organisms to the next patient✓ Answer
   • D.Administering vaccines to surgical patients

   The chain of infection requires an agent, reservoir, portal of exit, mode of transmission, portal of entry and susceptible host, and breaking any single link stops transmission. Reprocessing a contaminated instrument removes the vehicle of indirect contact transmission, which is the link sterile processing controls; vaccination addresses the susceptible host and isolation addresses the reservoir, but neither is a sterile processing intervention.

   Source: HSPA CRCST Content Outline Sec. 2.I.B (chain of infection); CDC Guideline for Disinfection and SterilizationReport a problem with this question

3. 3. A technician's hands are visibly soiled after removing gloves in decontamination. What is the MOST appropriate hand hygiene action?

   • A.Wipe hands on the gown, then apply alcohol-based hand rub
   • B.Put on a fresh pair of gloves and continue working
   • C.Apply a double volume of alcohol-based hand rub and let it dry
   • D.Wash with soap and running water, because alcohol-based rub does not remove visible soil✓ Answer

   Alcohol-based hand rubs are designed for hands that are not visibly soiled; organic material physically blocks alcohol contact and alcohol has no detergent action to remove it. Soap and running water provide the mechanical removal that visible soil requires, and hand hygiene is mandatory immediately after glove removal because gloves can have unrecognized defects.

   Source: CDC Hand Hygiene Guideline; OSHA 29 CFR 1910.1030(d)(2)(vi); HSPA CRCST Sec. 1.II.AReport a problem with this question

4. 4. Why is soap and water, rather than an alcohol-based hand rub, specifically indicated after handling items from a patient with Clostridioides difficile?

   • A.Alcohol does not kill bacterial spores, so mechanical washing is needed to physically remove them✓ Answer
   • B.Alcohol reacts chemically with C. difficile toxin and produces an irritant
   • C.Alcohol rubs are only approved for use in clean areas of the department
   • D.Soap contains an antibiotic that kills C. difficile

   C. difficile forms bacterial spores, which sit near the top of the microbial resistance hierarchy and are not inactivated by alcohol. Washing with soap and running water works by physically dislodging and rinsing the spores off the skin rather than by killing them, which is why the mechanical step cannot be replaced by a rub.

   Source: CDC Guideline for Disinfection and Sterilization (microbial resistance hierarchy); CDC Hand Hygiene GuidelineReport a problem with this question

5. 5. A technician will be manually scrubbing instruments at a sink where splashing is anticipated. Which eye and face protection is adequate?

   • A.A full-length face shield worn alone
   • B.A fluid-resistant surgical mask worn alone
   • C.Personal prescription eyeglasses worn with a fluid-resistant mask
   • D.Goggles or other eye protection worn together with a full-length face shield and a fluid-resistant mask✓ Answer

   PPE is selected for the exposure that is reasonably anticipated, and manual scrubbing generates splash toward the eyes, nose and mouth. Prescription eyeglasses lack side and top protection and are not PPE, a face shield alone does not protect the mucous membranes of the nose and mouth from inhaled aerosol, and a mask alone leaves the eyes exposed, so the combination is required.

   Source: OSHA 29 CFR 1910.1030(d)(3); HSPA CRCST Content Outline Sec. 2.I.FReport a problem with this question

6. 6. What is the correct sequence for REMOVING personal protective equipment after working in decontamination?

   • A.Gloves, gown, face shield or goggles, mask, then hand hygiene✓ Answer
   • B.Gown, gloves, mask, face shield, then hand hygiene
   • C.Face shield, mask, gloves, gown, then hand hygiene
   • D.Mask, gloves, gown, face shield, then hand hygiene

   Doffing follows a most-contaminated-first order so that heavily soiled items are removed while still-protected hands are covered. Gloves and gown carry the greatest bioburden and come off first, the mask is removed last because taking it off requires touching near the face, and hand hygiene immediately follows because the outside of all PPE is assumed contaminated.

   Source: CDC PPE Sequence guidance; HSPA CRCST Content Outline Sec. 2.I.FReport a problem with this question

7. 7. Under the Spaulding classification, a device that enters sterile tissue or the vascular system is classified as which category, and what reprocessing does it require?

   • A.Semicritical — intermediate-level disinfection is sufficient
   • B.Critical — it must be sterilized✓ Answer
   • C.Noncritical — intermediate-level disinfection is sufficient
   • D.Semicritical — high-level disinfection is sufficient

   Spaulding classifies devices by the infection risk of the tissue they contact. Critical devices bypass the body's natural barriers and enter normally sterile tissue or the bloodstream, so any surviving microorganism can be introduced directly into a sterile site, which is why sterilization rather than disinfection is required.

   Source: CDC Guideline for Disinfection and Sterilization (Spaulding classification)Report a problem with this question

8. 8. A flexible endoscope contacts intact mucous membranes but does not enter sterile tissue. What is the MINIMUM level of reprocessing required by the Spaulding classification?

   • A.Cleaning followed by intermediate-level disinfection
   • B.A detergent wipe-down only
   • C.Cleaning followed by high-level disinfection✓ Answer
   • D.Cleaning followed by low-level disinfection

   Devices that touch mucous membranes or non-intact skin are semicritical and require at minimum high-level disinfection, which kills all microorganisms except large numbers of bacterial spores. Intact mucous membranes are generally resistant to spores but not to vegetative bacteria, mycobacteria or viruses, and cleaning must always precede disinfection because residual soil shields organisms from the chemical.

   Source: CDC Guideline for Disinfection and Sterilization (Spaulding: semicritical devices); ANSI/AAMI ST91Report a problem with this question

9. 9. A technician finishes in decontamination and needs to help in the assembly area. What must occur before entering the clean area?

   • A.Keep the gown on but remove gloves so the hands are clean
   • B.Remove PPE in decontamination, perform hand hygiene, and change into clean attire as required by policy✓ Answer
   • C.Spray the PPE with disinfectant and continue wearing it
   • D.Walk directly through, since the technician is only passing through the room

   Sterile processing workflow is unidirectional from soiled to clean to sterile, and the barrier is enforced by attire as well as by walls and doors. PPE worn in decontamination is assumed contaminated on its outer surface, so carrying it into the clean workroom would transport bioburden onto processed devices and defeat the physical separation the layout is designed to create.

   Source: HSPA CRCST Content Outline Sec. 1.II.B (traffic control and workflow); ANSI/AAMI ST79 facility designReport a problem with this question

10. 10. What is the correct air pressure relationship between the decontamination area and the adjacent clean assembly area, and why?

    • A.Decontamination is positive and assembly is negative, so aerosols are pushed out of decontamination quickly
    • B.Decontamination is negative and assembly is positive, so airborne contaminants flow toward the dirtier area and not toward clean devices✓ Answer
    • C.Both areas are neutral so that air does not move between them at all
    • D.Both areas are positive so that outside air cannot enter either one

    Air always moves from higher pressure to lower pressure, so making decontamination negative relative to adjacent spaces pulls air inward and keeps aerosols generated by scrubbing, spraying and ultrasonic cleaning from drifting into the clean workroom. Positive pressure in assembly and sterile storage pushes air outward, which is the same principle stated as 'air flows from clean toward less clean.'

    Source: ANSI/AAMI ST79 (HVAC and physical facility requirements); ANSI/ASHRAE/ASHE 170Report a problem with this question

11. 11. Why is the air exhausted from the decontamination area not recirculated back into the sterile processing department?

    • A.Recirculation would raise the humidity above what sterilizers can tolerate
    • B.Recirculated air would make the clean workroom too warm for staff comfort
    • C.It may carry aerosolized contaminants from soiled devices that could be redeposited on clean or sterile items✓ Answer
    • D.Exhaust air is required for the sterilizer steam supply

    Cleaning activities aerosolize bioburden, so decontamination air is treated as contaminated and exhausted directly to the outside rather than returned by room recirculating units. Recirculating it would defeat the entire clean-to-dirty airflow design by carrying organisms back over packaged or sterilized devices.

    Source: ANSI/AAMI ST79 (decontamination area ventilation, no recirculation); ANSI/ASHRAE/ASHE 170Report a problem with this question

12. 12. A department finds that the humidity in the clean workroom has been outside the specified range for two days. What is the MOST appropriate FIRST action?

    • A.Continue as normal, since humidity does not affect packaged sterile items
    • B.Immediately discard all packages processed during the two-day period
    • C.Recall and reprocess every item currently in sterile storage
    • D.Document the excursion, notify leadership and facilities, and conduct a multidisciplinary risk assessment on affected inventory✓ Answer

    An out-of-range environmental reading is a non-conformance, not automatic evidence that products are unsafe, because package integrity and sterility depend on multiple factors. Standards direct the facility to document, notify and convene a risk assessment involving sterile processing leadership, facilities engineering, infection prevention and risk management so the decision about affected inventory is evidence-based rather than reflexive.

    Source: ANSI/AAMI ST79 (environmental monitoring and risk assessment for out-of-range conditions)Report a problem with this question

13. 13. Under the OSHA Bloodborne Pathogens Standard, how often must the written Exposure Control Plan be reviewed and updated?

    • A.Every five years, or after an accreditation survey
    • B.Only when a new employee is hired
    • C.Only after a documented exposure incident occurs
    • D.At least annually, and whenever new or modified tasks or procedures affect occupational exposure✓ Answer

    The standard requires an annual review plus an update whenever tasks, procedures or employee positions change, because the plan's purpose is to reflect the exposures that actually exist in current work practice. A plan that is only revised after an incident would document hazards retrospectively instead of preventing them.

    Source: OSHA 29 CFR 1910.1030(c)(1)(iv)Report a problem with this question

14. 14. A technician is stuck by a contaminated sharp while emptying a case cart. What should be done FIRST?

    • A.Apply a bandage and report it at the end of the shift
    • B.Wash the wound with soap and water immediately, then report the exposure right away✓ Answer
    • C.Finish emptying the cart so contaminated items are not left unattended
    • D.Locate the patient chart to determine whether follow-up is necessary

    Immediate washing reduces the inoculum at the wound site, and prompt reporting is what starts the confidential medical evaluation and post-exposure follow-up, which is time-sensitive because prophylaxis is most effective when begun quickly. Delaying to finish a task or to investigate the source patient wastes that window, and source-patient evaluation is performed by the medical provider, not the technician.

    Source: OSHA 29 CFR 1910.1030(f)(3) post-exposure evaluation and follow-upReport a problem with this question

15. 15. Which practice for handling contaminated sharps in the decontamination area is correct?

    • A.Bend or break needles so they take up less space in the container
    • B.Recap needles with two hands before placing them in the container
    • C.Keep sharps visible, never reach blindly into a sink or container, and dispose of them in a puncture-resistant labeled container✓ Answer
    • D.Pick sharps out of the bottom of a filled sink by feel to avoid splashing

    Contaminated sharps must never be bent, sheared, broken or recapped by hand, because each of those actions puts a hand in the path of the point. Keeping sharps visible and using work-practice controls addresses the hazard before PPE does, consistent with the hierarchy that places engineering and work-practice controls ahead of personal protective equipment.

    Source: OSHA 29 CFR 1910.1030(d)(2)(vii) and (d)(4)(iii)(A); HSPA CRCST Sec. 2.I.CReport a problem with this question

16. 16. Why are routine cleaning and standard steam sterilization parameters considered insufficient for instruments suspected of prion (CJD) contamination?

    • A.Prions are living bacteria that grow back after normal cycles complete
    • B.Prions are only a hazard if the instrument is used again within 24 hours
    • C.Prions destroy stainless steel, so instruments must be replaced rather than reprocessed
    • D.Prions are the most resistant infectious agents and are not reliably inactivated by routine parameters, so enhanced protocols are required✓ Answer

    Prions are misfolded proteins with no nucleic acid, sitting above bacterial spores at the top of the microbial resistance hierarchy, so cycles validated against spores do not guarantee their inactivation. Special handling therefore relies on dedicated or single-use instruments, keeping devices moist so protein does not dry on, and the enhanced chemical and extended steam protocols specified in guideline-based facility policy.

    Source: CDC Guideline for Disinfection and Sterilization (prion reprocessing); HSPA CRCST Sec. 2.I.BReport a problem with this question

17. 17. Which personnel practice is required in sterile processing work areas?

    • A.Natural nails kept short and clean, with no artificial nails, extenders or chipped polish✓ Answer
    • B.Nail polish is acceptable in any condition as long as nails are short
    • C.A single plain ring is acceptable because it does not hold moisture
    • D.Artificial nails are acceptable if gloves are worn over them

    Artificial nails, extenders and chipped polish create crevices and lifted edges that harbor microorganisms and resist hand hygiene, and long or hard nails also tear glove material. Rings, watches and bracelets are removed for the same reasons: they trap moisture and organisms under them and prevent effective cleaning of the skin.

    Source: HSPA CRCST Content Outline Sec. 1.II.A (dress code and personal hygiene); CDC Hand Hygiene GuidelineReport a problem with this question

18. 18. What is the correct practice regarding facility-provided scrub attire and head coverings in sterile processing?

    • A.A head covering is optional in the assembly area because no sterile field is open
    • B.Scrubs are donned at the facility and changed when soiled, and head coverings must completely confine all hair including facial hair✓ Answer
    • C.Scrubs may be worn home if a lab coat is worn over them in the parking lot
    • D.Scrubs may be laundered at home as long as hot water is used

    Attire is a barrier that works in both directions: it keeps outside contaminants off processed devices and keeps workplace bioburden from leaving the department on clothing. Hair and skin squames are a continuous source of shed microorganisms, so complete hair confinement including beards is required wherever devices are processed or stored, and facility laundering ensures a validated, monitored process rather than an uncontrolled home wash.

    Source: HSPA CRCST Content Outline Sec. 1.II.A; AORN Guideline for Surgical AttireReport a problem with this question

19. 19. A technician has weeping dermatitis on both hands. What is the MOST appropriate action?

    • A.Wear two pairs of gloves and continue working in decontamination
    • B.Apply a bandage and switch to the assembly area only
    • C.Continue working but use alcohol-based rub instead of soap to reduce irritation
    • D.Report the condition and follow the facility work-restriction policy before handling contaminated items or clean devices✓ Answer

    Non-intact skin is both a portal of entry for bloodborne pathogens into the worker and a reservoir that can shed organisms onto devices, so it creates risk in both directions. The correct step is reporting and following the work-restriction policy, because the decision about assignment is a documented occupational health determination, not something the technician mitigates with extra gloves.

    Source: HSPA CRCST Content Outline Sec. 1.II.A (personnel health); CDC/HICPAC personnel health recommendationsReport a problem with this question

20. 20. How should soiled instruments be handled at the point of use to limit biofilm formation?

    • A.Remove gross soil, keep the instruments moist, and transport them promptly to decontamination✓ Answer
    • B.Wrap the instruments in a dry towel and hold them until the end of the day
    • C.Allow the instruments to air dry so soil flakes off during transport
    • D.Soak the instruments in saline until transport is convenient

    Biofilm forms when organisms in dried soil attach to the device surface and produce a protective matrix that resists detergents and disinfectants, and lumens are the highest-risk site. Keeping devices moist and moving them promptly prevents soil from drying and anchoring; saline is never used because chloride ions pit and corrode stainless steel.

    Source: ANSI/AAMI ST79 (point-of-use treatment); CDC Guideline for Disinfection and SterilizationReport a problem with this question

21. 21. Which pairing correctly distinguishes a regulatory requirement from voluntary consensus guidance?

    • A.ANSI/AAMI standards are federal law; OSHA publishes voluntary recommendations
    • B.CDC guidelines are federal regulations; FDA publishes voluntary suggestions
    • C.OSHA bloodborne pathogen rules are enforceable law; ANSI/AAMI and AORN documents are voluntary standards that define the standard of care✓ Answer
    • D.AORN guidelines are enforceable law; EPA registration is voluntary for disinfectants

    OSHA, FDA, CMS, EPA and DOT issue mandatory requirements with the force of law, while ANSI/AAMI, AORN and CDC/HICPAC publish consensus recommendations. Voluntary documents still matter because accrediting organizations and courts treat them as the standard of care, which is how they become enforceable indirectly rather than directly.

    Source: HSPA CRCST Content Outline Sec. 1.III (regulations vs. standards)Report a problem with this question

22. 22. A device manufacturer's IFU specifies a cleaning step the department cannot perform with its current equipment. What is the correct action?

    • A.Follow the department policy instead, since policy is approved by the facility
    • B.Do not process the device; escalate so the facility can obtain the capability or arrange processing elsewhere✓ Answer
    • C.Extend the cleaning time to compensate for the missing step
    • D.Substitute the closest available equivalent process and document the substitution

    The manufacturer's written IFU reflects the only process validated for that specific device, so an improvised substitute has no evidence that it renders the device clean or sterile. When an IFU, a standard and a policy conflict, the validated IFU governs, and if the facility cannot meet it the device cannot be safely processed there, which makes escalation the correct response rather than an autonomous workaround.

    Source: ANSI/AAMI ST79 (manufacturer's written IFU supremacy); FDA validated reprocessing instructionsReport a problem with this question

Practice questions based on the HSPA CRCST Certification Exam Content Outline, ANSI/AAMI ST79 sterility-assurance practice, and CDC/HICPAC disinfection and sterilization guidance. CRCST is a mark of the Healthcare Sterile Processing Association; this site is not affiliated with or endorsed by HSPA. Always follow the device manufacturer's written instructions for use, your facility's policies, and the current edition of the applicable standards. About the CRCST exam →