HSPA Sterile Processing (CRCST) — All Questions

What is the fundamental difference between a gravity displacement cycle and a dynamic-air-removal (prevacuum) cycle?

• a.Gravity operates at a lower temperature than any dynamic-air-removal cycle
• b.Gravity uses saturated steam and dynamic-air-removal uses dry heat
• c.Gravity relies on incoming steam to push air down and out the drain, while dynamic-air-removal uses vacuum pulses to actively pull air out before steam is admitted✓
• d.Gravity requires a biological indicator while dynamic-air-removal does not

In a gravity cycle, steam entering the chamber displaces cooler, heavier air downward through the drain, which is slower and less reliable for porous items and lumens. Dynamic-air-removal cycles mechanically evacuate air with vacuum pulses or steam flushes so steam contacts every surface almost immediately. Both cycles use saturated steam, both are monitored with biological indicators, and both can run at 270 degrees F.AAMI ST79

A wrapped instrument set is being sterilized in a dynamic-air-removal steam sterilizer at 270 degrees F (132 degrees C). What is the typical minimum exposure time?

• a.1 minute
• b.15 minutes
• c.30 minutes
• d.4 minutes✓

Four minutes at 270 degrees F is the commonly validated exposure time for wrapped goods in a dynamic-air-removal cycle because air is removed before the exposure phase begins. Fifteen minutes at 270 degrees F and thirty minutes at 250 degrees F are gravity cycle parameters, which take longer because air removal is passive. One minute is not a validated exposure time for any wrapped steam cycle, and the device manufacturer instructions always govern the final selection.AAMI ST79

What is a standard gravity displacement steam cycle for a wrapped instrument set at 250 degrees F (121 degrees C)?

• a.60 minutes
• b.3 minutes
• c.30 minutes✓
• d.10 minutes

At the lower temperature of 250 degrees F, a gravity cycle needs about 30 minutes of exposure to achieve the required lethality, plus drying time. Shorter exposures of 3 or 10 minutes do not deliver sufficient lethality at that temperature for a wrapped set. Sixty minutes exceeds the validated requirement and unnecessarily stresses instruments; time and temperature are inversely related, so higher temperature permits shorter exposure.AAMI ST79

A technician opens the department at the start of the day shift and must schedule the Bowie-Dick test for a dynamic-air-removal sterilizer. How often is the test required?

• a.Each day the sterilizer is used, in the first cycle of the day after the warm-up cycle✓
• b.Only after a repair to the vacuum pump
• c.In every load that contains an implant
• d.Once per week, on the same day each week

The Bowie-Dick test verifies air removal and steam penetration and is run daily in an otherwise empty chamber before the first processed load, typically after a warm-up cycle. It is an air-removal test, not a lethality test, so it does not belong in implant loads and does not replace biological monitoring. It is also repeated after repairs, but that is in addition to, not instead of, the daily requirement.AAMI ST79

A Bowie-Dick test sheet comes out of the sterilizer with a pale, uneven center and darker edges. What does this indicate and what should be done?

• a.Excessive steam pressure; reduce the set point and continue processing
• b.A normal result caused by the density of the test pack; the sterilizer may be used
• c.Incomplete air removal; the sterilizer should not be used for patient loads until the problem is corrected and a passing test is obtained✓
• d.A failed biological indicator; quarantine all implants processed that week

Uneven or lighter color change, especially in the center, means residual air remained in the pack and steam did not penetrate uniformly, which points to an air leak, a faulty vacuum pump, or a plugged drain. The sterilizer must be taken out of service for patient loads until the cause is found and a passing test is achieved. A non-uniform result is never normal, and the Bowie-Dick test measures air removal rather than pressure or microbial kill.AAMI ST79

After a tray fails its internal chemical indicator, the supervisor reviews the fundamentals with the team. Which four parameters must all be satisfied for steam sterilization to be effective?

• a.Time, temperature, moisture in the form of saturated steam, and direct contact with all surfaces✓
• b.Detergent, water quality, temperature, and packaging material
• c.Vacuum depth, drying time, cooling time, and package integrity
• d.Pressure, humidity, load weight, and cycle number

Steam sterilization depends on saturated steam reaching every surface at the required temperature for the required time, which is why cleaning, correct packaging, and proper loading matter so much. Pressure is only the means of achieving the temperature, not an independent parameter. Drying, cooling, and cleaning variables affect the outcome and package integrity but are not the four critical parameters of the sterilization process itself.AAMI ST79

Why is saturated steam, rather than superheated or wet steam, required for steam sterilization?

• a.Only saturated steam can pass through a sterilization wrapper
• b.Wet steam carries more heat energy and therefore sterilizes faster
• c.Saturated steam gives up its latent heat on contact with cooler surfaces, and both superheat and excess moisture disrupt that heat transfer✓
• d.Superheated steam is too cold to kill spores

Sterilization depends on condensation, which releases latent heat directly onto the item surface, and saturated steam near 97 percent dryness delivers that transfer efficiently. Superheated steam behaves like hot dry air and requires far longer exposure times, while wet steam carries excess water that causes wet packs and reduced penetration. Steam of any quality can physically pass through a wrapper, so that is not the distinguishing factor.AAMI ST79

Peel pouches are being loaded onto a sterilizer shelf. What is the correct placement?

• a.Stacked flat, plastic side up, so condensate runs off the film
• b.Laid flat and overlapping to maximize the number of pouches per shelf
• c.Positioned on edge in a rack, paper surface facing the plastic surface of the next pouch✓
• d.Stacked flat, paper side up, no more than ten deep

Placing pouches on edge with paper facing plastic lets steam enter through the porous paper and lets condensate drain away, which also improves drying. Stacking pouches flat traps air and moisture between them and blocks the porous side. Overlapping pouches likewise prevents steam contact and is a common cause of wet packs and failed indicators.AAMI ST79

A mixed load contains wrapped metal basin sets and textile packs. How should the load be arranged?

• a.Place metal and basin items on the lower shelves and textile packs on the upper shelves✓
• b.Place all items on a single shelf so the load remains compact
• c.Alternate metal and textile items on every shelf for even heat distribution
• d.Place textile packs on the bottom so metal weight does not crush them

Condensate forms on and drips from metal items, so putting them low keeps that moisture off absorbent textile packs and prevents wet packs. Placing textiles beneath metal is the classic cause of soaked wrappers. Alternating or compacting the load restricts steam circulation and creates cold spots, and items should never be packed tightly against each other or the chamber walls.AAMI ST79

A tray is removed from the sterilizer and the outer wrapper feels damp to the touch. What is the correct action?

• a.Set the tray aside until the moisture evaporates, then send it to storage
• b.Wipe the wrapper dry with a clean lint-free towel and release the tray
• c.Place the tray back in the sterilizer for an additional drying cycle and then release it
• d.Consider the package contaminated, do not use or store it, and reprocess the contents after investigating the cause✓

Moisture provides a wicking pathway for microorganisms from the outer surface to the contents, so a wet pack is considered contaminated regardless of whether the cycle parameters were met. The contents must be rewrapped and reprocessed, and the cause must be investigated. Air drying, wiping, or re-running only the drying phase does not restore sterility to a package that has already wicked.AAMI ST79

Wet packs are appearing intermittently across several loads. Which of the following is the least likely cause?

• a.Using a dynamic-air-removal cycle instead of a gravity cycle✓
• b.Poor steam quality with excess moisture in the supply line
• c.Overloading the chamber or packing items too densely
• d.Insufficient drying time or opening the door too early

Dynamic-air-removal cycles generally dry better than gravity cycles because the post-cycle vacuum helps pull moisture out, so cycle type is not a likely cause of wet packs. Overloading, dense packing, short drying times, premature door opening, clogged drains, faulty steam traps, and wet incoming steam are all recognized contributors. Cooling loads on a cold metal surface or in a drafty area also produces condensation.AAMI ST79

After a steam cycle finishes and the load is removed, how should the load be handled?

• a.Unloaded and immediately handled by staff wearing clean gloves
• b.Left undisturbed on the cart in a low-traffic, draft-free area until fully cool, typically 30 minutes or longer, before it is touched or moved✓
• c.Transferred immediately to sterile storage to protect it from room air
• d.Placed on a solid countertop and covered with a clean towel while it cools

Hot packages are vulnerable because handling them can drive condensation and contamination through the packaging, so the load is left to cool on the cart away from vents, drafts, and traffic. Cooling times of 30 minutes to an hour or more are common depending on load density. Placing hot items on a cold solid surface or covering them traps condensate, and gloves do not protect a package that is still hot and damp.AAMI ST79

Immediate-use steam sterilization (IUSS) is requested for a single dropped instrument during a case. Which statement is correct?

• a.IUSS eliminates the need for physical, chemical, and biological monitoring
• b.The item must still be thoroughly cleaned and decontaminated before it is placed in the sterilizer✓
• c.The item may be flash sterilized unwrapped and stored for later use if kept covered
• d.Cleaning may be abbreviated because the exposure temperature is higher

IUSS shortens the packaging and drying steps, not the cleaning step, and a device that is not properly cleaned cannot be sterilized by any cycle. Items processed by IUSS are transported for immediate use and are not stored for later cases. Physical monitors and chemical indicators are used with every IUSS cycle, and the sterilizer is monitored biologically at least daily or weekly per policy.AAMI ST79

Which practice regarding IUSS and implants is correct?

• a.Implants may be processed by IUSS if a Class 1 process indicator is placed on the tray
• b.Implants may be routinely processed by IUSS as long as the case is urgent
• c.IUSS of implants should be avoided; if unavoidable in a documented emergency, a rapid-readout biological indicator with a Class 5 integrating indicator is run and the event is documented✓
• d.Implants processed by IUSS require no biological monitoring because the cycle is unwrapped

Because a failed implant sterilization carries severe patient consequences, implants should be sterilized in a full terminal cycle and quarantined until the biological indicator result is known. In a documented emergency, IUSS may be used with a process challenge device containing a rapid-readout biological indicator and a Class 5 integrating indicator, and the exception must be recorded. Convenience or urgency alone does not justify the practice, and an external process indicator only shows exposure.AAMI ST79

A typical IUSS gravity cycle for nonporous metal instruments only is 270 degrees F (132 degrees C) for 3 minutes. What changes when the item is porous, cannulated, or has a lumen?

• a.The cycle is unchanged because IUSS parameters are fixed
• b.The item cannot be sterilized by steam under any circumstance
• c.A longer exposure, commonly 10 minutes in a gravity cycle, is required per the device manufacturer instructions✓
• d.The temperature is lowered to 250 degrees F and the time stays at 3 minutes

Porous items, lumens, and complex devices are harder for steam to penetrate, so validated IUSS parameters extend the exposure time, commonly to 10 minutes in a gravity cycle. The device manufacturer written instructions for use always define the required cycle. Lowering the temperature reduces lethality, IUSS parameters are not fixed across device types, and most such devices are perfectly steam compatible.AAMI ST79

A surgeon sends a heat-sensitive device with a long narrow lumen and asks whether it can be processed with ethylene oxide. Which statement describes ethylene oxide sterilization?

• a.A dry heat method used for oils, powders, and petroleum-based products
• b.A liquid immersion method used at the point of use for endoscopes
• c.A low-temperature gas method used for heat-sensitive and moisture-sensitive devices, including many long or narrow lumens✓
• d.A high-temperature method used as the fastest option for routine metal instruments

Ethylene oxide sterilizes at low temperature and penetrates well, which makes it valuable for delicate electronics, plastics, and devices with long narrow lumens that other low-temperature methods cannot handle. Its drawbacks are a long total cycle including mandatory aeration and significant worker safety and environmental controls. Dry heat is the method used for oils and powders, and liquid chemical sterilants are the point-of-use immersion option.AAMI ST79

Why must every ethylene oxide load undergo an aeration phase before items are released?

• a.Residual ethylene oxide absorbed into plastics and rubber is toxic and must be driven off to protect patients and staff✓
• b.Aeration is required only for loads that contain implants
• c.Aeration completes the microbial kill that the exposure phase started
• d.Aeration restores the humidity that was removed during the cycle

Ethylene oxide is a recognized carcinogen and irritant that is absorbed by polymers, so mechanical aeration at elevated temperature is required to reduce residuals to safe levels before handling or patient contact. Aeration times of about 8 to 12 hours or more are typical and are set by the device and sterilizer manufacturers. The kill occurs during exposure, not aeration, and the requirement applies to every load regardless of contents.OSHA

What are the byproducts of a hydrogen peroxide gas plasma sterilization cycle, and what does this mean operationally?

• a.Formaldehyde and methanol, which require a chemical scrubber
• b.Ethylene glycol and chlorohydrin, which require a long aeration phase
• c.Water vapor and oxygen, so no aeration period is required and items can be used immediately after the cycle✓
• d.Ozone and nitrogen, which require ventilation of the room for one hour

Hydrogen peroxide breaks down into water and oxygen, so there is no toxic residual and loads are available for immediate use, which is a major advantage over ethylene oxide. Ethylene glycol and ethylene chlorohydrin are ethylene oxide byproducts that drive its aeration requirement. Formaldehyde and ozone are separate sterilization agents, not plasma byproducts.AAMI ST79

An ozone sterilization system is being introduced. Which statement about ozone sterilization is accurate?

• a.Ozone is generated on demand from oxygen and water, sterilizes at low temperature, and reverts to oxygen with no toxic residue✓
• b.Ozone is generated from ethylene oxide and requires the same aeration as EO
• c.Ozone sterilizes at 270 degrees F and can replace steam for textile packs
• d.Ozone is used primarily for oils, powders, and anhydrous materials

Ozone sterilizers create the sterilant on site from medical-grade oxygen and water, which removes the need for stored chemical cartridges, and the ozone converts back to oxygen at the end of the cycle. It is a low-temperature method for heat-sensitive and moisture-sensitive devices, not a steam substitute for textiles. Dry heat, not ozone, is the method for oils and powders, and ozone is unrelated to ethylene oxide.AAMI ST79

A department is deciding which sterilization method to use for a heat-stable stainless steel instrument set. Which method should be selected and why?

• a.Steam, because it is the safest, fastest, least expensive, and most reliable method for heat-tolerant and moisture-tolerant items✓
• b.Dry heat, because it does not corrode stainless steel
• c.Hydrogen peroxide gas plasma, because it is the shortest cycle available
• d.Ethylene oxide, because it penetrates box locks better than steam

Whenever a device tolerates heat and moisture, steam is the preferred method because it is nontoxic, inexpensive, well validated, and rapid. Low-temperature methods are reserved for devices that cannot survive steam, and each carries material restrictions, cost, and in the case of ethylene oxide, worker safety burdens. Dry heat requires very long exposure times and is limited to a narrow set of materials.AAMI ST79

A technician receives a jar of petroleum-based lubricant and a container of powder that must be sterilized. Which method applies, and what are representative parameters?

• a.Rigid containers with filters, at 270 degrees F for 4 minutes
• b.Oils, petroleum-based lubricants, and powders, at approximately 320 degrees F for 2 hours or 340 degrees F for 1 hour✓
• c.Textile packs, at 275 degrees F for 3 minutes
• d.Flexible endoscopes, at 250 degrees F for 30 minutes

Dry heat is used for anhydrous materials that steam cannot penetrate, such as oils, ointments, and powders, and it needs long exposure at high temperature because heat transfer without moisture is inefficient. Flexible endoscopes are heat sensitive and are high-level disinfected or low-temperature sterilized. The 270 and 275 degrees F short cycles listed are steam parameters, not dry heat.AAMI ST79

Rigid sterilization containers are being loaded into a steam sterilizer along with wrapped trays. What is correct practice?

• a.Place containers flat on the shelf, do not stack unless the container manufacturer validates stacking, and keep them from touching chamber walls✓
• b.Stack containers three high to conserve shelf space
• c.Place containers on the top shelf so condensate drains onto the wrapped trays below
• d.Turn containers on edge so water drains from the filter ports

Containers must sit level so condensate can drain through the designed pathway, and stacking is permitted only when the container manufacturer has validated it, because stacking can block steam access and trap moisture. Items should never contact chamber walls, where they can be scorched or collect condensate. Putting containers above absorbent wrapped packs invites wet packs, and turning them on edge defeats the drainage design.AAMI ST79

A technician notices the sterilizer printout shows the chamber reached only 268 degrees F during a cycle set for 270 degrees F, although the chemical indicator changed color. What should be done?

• a.Release the load but note the discrepancy in the log for the next preventive maintenance visit
• b.Do not release the load; the physical monitor shows the cycle parameters were not met, so the load is quarantined and the sterilizer is evaluated✓
• c.Rerun the same load in the same sterilizer without further investigation
• d.Release the load, since the chemical indicator confirms sterility

Physical monitors are an independent record of what the chamber actually did, and a load that did not meet its specified parameters cannot be released even if an indicator changed color. Chemical indicators respond to conditions but do not prove that all critical parameters were achieved. Rerunning without investigation ignores a possible equipment fault that will affect subsequent loads.AAMI ST79

A student asks a technician what it means when a process is described as achieving a sterility assurance level of 10 to the minus 6. What is the correct explanation?

• a.Six biological indicators must be run in every load
• b.Six log reductions of bioburden have occurred during the cycle
• c.The sterilant concentration is one part per million at the end of the cycle
• d.The probability that a single item remains nonsterile after processing is one in one million✓

SAL is a probability statement about the likelihood that a viable microorganism survives on a processed item, and 10 to the minus 6 is the accepted level for devices intended for sterile use. It is not a count of log reductions achieved, although the two concepts are mathematically related through the starting bioburden. It has nothing to do with the number of indicators used or with residual sterilant concentration.AAMI ST79

A technician is loading a steam sterilizer and wants to fit as many trays as possible before the shift ends. How full should the chamber be loaded?

• a.Loosely, with space between packages and between packages and the chamber walls so steam can circulate freely✓
• b.At least three quarters full, because partial loads waste energy
• c.Only with identical items, never mixed loads, regardless of spacing
• d.Completely full, with items packed tightly so nothing shifts during the cycle

Free circulation of steam and unobstructed air removal require space around every package, so overloading is a leading cause of sterilization failure and wet packs. Packing tightly or filling to a minimum percentage for efficiency compromises the process. Mixed loads are acceptable when items are arranged correctly, for example metal below textiles, and when all items share the same validated cycle.AAMI ST79

A liquid chemical sterilant such as peracetic acid is used to process a device. What is the key limitation of this method?

• a.It requires an aeration period of at least four hours
• b.It produces a package that has a two-week shelf life
• c.It cannot be used on immersible devices
• d.The device is processed wet and unwrapped, so it cannot be packaged or stored and must be used immediately✓

Liquid chemical sterilization occurs in a chamber of circulating solution and the device emerges wet, meaning there is no barrier packaging and therefore no shelf life; the item is transferred aseptically and used right away. The method is intended specifically for immersible heat-sensitive devices. No aeration phase is involved, and the absence of packaging is precisely why storage is impossible.AAMI ST79

An instrument manufacturer's instructions for use specify a prevacuum cycle at 270 degrees F for 4 minutes with an 8-minute dry time, but department policy uses a 30-minute dry time for all trays. Which should be followed?

• a.Always follow department policy, because it is approved by the infection prevention committee
• b.Always use the shortest parameters listed anywhere, to protect the instruments
• c.Follow the longer validated department cycle only if it is also within what the device manufacturer permits; the device manufacturer instructions for use set the required minimum parameters and must be reconciled with sterilizer capability✓
• d.Choose whichever parameters the operating room requests for turnaround

Reprocessing must follow the device manufacturer written instructions for use, validated against what the facility sterilizer can actually deliver, and any conflict is resolved before the device is put into service rather than by local preference. Longer drying is generally acceptable, but exposure parameters cannot be shortened below the validated minimum. Turnaround pressure and blanket policy never override validated instructions.AAMI ST79

During a steam cycle the sterilizer aborts and displays an air leak alarm. What is the correct response?

• a.Release the load if the external chemical indicators have changed color
• b.Consider the load unsterile, remove it from service, and do not release it; report the alarm so the sterilizer can be evaluated and repaired✓
• c.Restart the same cycle immediately, since aborted cycles do not affect the load
• d.Open the door and allow the load to dry, then run a Bowie-Dick test and release the load

An aborted cycle means the process was not completed as validated, so the entire load is treated as unsterile and must be reprocessed after the equipment problem is resolved. An air leak specifically means air remained in the chamber and steam penetration cannot be assumed. External indicators show only that a package was exposed to some conditions, and a Bowie-Dick test performed later says nothing about a load that already failed.AAMI ST79

Which organism is used in biological indicators for steam sterilization, and why?

• a.Geobacillus stearothermophilus, because its spores are highly resistant to moist heat✓
• b.Staphylococcus aureus, because it survives on dry surfaces
• c.Clostridioides difficile, because it is a common healthcare pathogen
• d.Bacillus atrophaeus, because its spores are highly resistant to moist heat

Biological indicators use a highly resistant spore population that is harder to kill than the microorganisms found on devices, and Geobacillus stearothermophilus fills that role for steam, hydrogen peroxide, and ozone. Bacillus atrophaeus is used for ethylene oxide and dry heat. Vegetative pathogens such as staphylococci and clinical spore formers such as C. difficile are far less resistant and are never used as process challenge organisms.AAMI ST79

A department is setting its biological monitoring policy for a steam sterilizer used for routine loads. How frequently should a biological indicator be run?

• a.Monthly, and after any repair
• b.Only in loads containing implants
• c.At least daily on each day the sterilizer is used, preferably in every load, and always in loads containing implants✓
• d.Annually, as part of preventive maintenance

Biological monitoring at least once each day of use is the minimum expectation, with every-load monitoring recommended because it narrows the recall population if a failure occurs. Implant loads always require a biological indicator in a process challenge device, and the load is quarantined until the result is read. Monthly and annual intervals leave far too many loads unverified.AAMI ST79

A supervisor asks a technician to assemble a process challenge device for the daily biological indicator test. What is a process challenge device?

• a.A software module that records cycle data for traceability
• b.A tray of instruments used only for training new technicians
• c.A test assembly that presents a challenge to the sterilization process equal to or greater than the most difficult item routinely processed, containing a biological or chemical indicator✓
• d.A device that measures chamber pressure independently of the sterilizer gauges

A PCD, such as a commercial test pack or a homemade AAMI test pack, places the indicator in the hardest-to-sterilize location so that a passing result gives confidence that easier items were also processed. The design must challenge the process at least as much as the routine load. Pressure verification, training, and electronic record keeping are separate functions unrelated to the definition of a PCD.AAMI ST79

Where should the process challenge device be placed in a steam sterilizer chamber for routine biological monitoring?

• a.In the geometric center of the load, surrounded by the densest packs
• b.Outside the chamber, taped to the sterilizer door
• c.In the area identified as the most difficult for the sterilant to reach, typically on the bottom shelf near the front over the drain✓
• d.On the top shelf at the rear of the chamber

Air is heaviest and settles low near the drain, so the front bottom of the chamber is the recognized cold spot for a steam sterilizer and is where the PCD is placed. Testing an easy location would give a falsely reassuring result. The exact placement follows the sterilizer manufacturer instructions, and an indicator outside the chamber tests nothing.AAMI ST79

Which of the following are physical monitors of a sterilization cycle?

• a.Integrating indicators placed inside packs
• b.Time, temperature, and pressure readings on gauges, digital displays, and cycle printouts✓
• c.Autoclave tape and pouch indicators
• d.Spore strips and self-contained vials

Physical monitors are the sterilizer's own instrumentation and recording output, and the operator must review and initial the printout or record for each cycle before the load is released. Tape and pouch indicators are chemical Class 1, and integrating indicators are chemical Class 5. Spore strips and vials are biological indicators.AAMI ST79

A biological indicator from this morning's steam load is positive. What is the first action?

• a.Notify the operating room that items may have been unsterile but allow already distributed items to be used
• b.Take the sterilizer out of service and immediately recall and quarantine the items from that load and from every load back to the last negative biological indicator✓
• c.Repeat the test at the end of the shift and continue processing loads in the meantime
• d.Discard the indicator as a false positive, since spore vials are unreliable

A positive biological indicator means the process cannot be assumed to have been lethal, so the sterilizer is removed from service and every load processed since the last negative result is retrieved, quarantined, and reprocessed. Continuing to run loads or waiting to retest extends the exposure to patients. Positives are investigated, not assumed to be false, and previously distributed items must be located, not released for use.AAMI ST79

After a positive biological indicator, the sterilizer is inspected, a probable cause is corrected, and testing resumes. What is generally required before the sterilizer returns to routine service?

• a.A signed statement from the operator that the load appeared normal
• b.Three consecutive cycles with negative biological indicators in an empty chamber, and for dynamic-air-removal sterilizers three passing Bowie-Dick tests as well✓
• c.A single passing chemical indicator in a full production load
• d.One passing biological indicator run in a fully loaded chamber

Requalification after a failure or a major repair uses three consecutive empty-chamber cycles with negative biological indicators, with Bowie-Dick testing added for dynamic-air-removal sterilizers, to demonstrate the equipment is reliably performing again. A chemical indicator does not demonstrate microbial lethality, and one biological indicator in a production load is not sufficient evidence of restored performance. Operator observation is not a qualification method.AAMI ST79

An implant is processed in a terminal steam cycle with a rapid-readout biological indicator. When may the implant be released?

• a.At the end of the shift, regardless of the biological indicator result
• b.Immediately, if the Class 5 integrating indicator inside the tray has changed
• c.Only after the biological indicator result is available and negative, except in a documented emergency✓
• d.Only after 48 hours of incubation, with no exceptions

Implant loads are quarantined until the biological indicator reads negative, because a failure would place a permanently implanted device in a patient. Emergency release before the result is available is permitted only when it is documented and the surgeon is informed, and the result is tracked to completion. A Class 5 indicator supports early release decisions in an emergency but does not by itself satisfy the requirement, and modern rapid-readout indicators give results in far less than 48 hours.AAMI ST79

A recall requires the department to trace every package from a suspect cycle. What information must the load record contain?

• a.Only the date and the technician initials
• b.Only the sterilizer number and the cycle type
• c.Sterilizer identification, cycle or load number, date and time, contents of the load, cycle parameters, operator identification, and the results of physical, chemical, and biological monitoring✓
• d.Only a list of the departments the items were sent to

Complete load documentation permits a targeted recall, links a specific package to a specific cycle, and demonstrates that monitoring was performed and reviewed. Each package also carries a lot control label with the sterilizer, cycle, and date so it can be matched back to the record. Partial records leave gaps that force a much broader and more disruptive recall.AAMI ST79

A nurse reports that a tray opened in the operating room contained an internal chemical indicator that did not change. What is the correct action?

• a.Use the tray but document the indicator failure afterward
• b.Do not use the tray, return it for reprocessing, and investigate the cycle records and the rest of the load✓
• c.Replace the indicator and reseal the tray in the operating room
• d.Use the tray if the external tape changed color, since two indicators are redundant

An internal indicator that failed to change means sterilant may not have reached the interior of the package, so the tray is treated as unsterile and reprocessed while the load records and remaining packages are reviewed. External tape only shows the package was exposed to a process, so it cannot override an internal failure. Resealing or using the tray and documenting later places the patient at risk.AAMI ST79

How should the daily Bowie-Dick test cycle be run?

• a.In any cycle of the day, as long as the result is recorded
• b.In a fully loaded chamber, to reflect real conditions
• c.In an otherwise empty chamber, in the first cycle of the day after a warm-up cycle, at 270 to 275 degrees F for the time specified by the test manufacturer, usually not exceeding 4 minutes✓
• d.Together with a biological indicator, so both tests share the same cycle

The Bowie-Dick test is run in an empty chamber so the only challenge to air removal is the test pack itself, and a warm-up cycle first brings the chamber and jacket to operating condition. Exposure time follows the test manufacturer instructions and is typically limited to about 3.5 to 4 minutes, because overexposure can produce a false pass. Running it in a production load or combining it with biological monitoring invalidates the intent of the test.AAMI ST79

What is the correct handling of the control biological indicator that accompanies a test lot?

• a.It is stored in a refrigerator until the end of the month
• b.It is discarded because it is not part of the record
• c.It is not sterilized, is incubated with the processed indicator from the same lot, and must show growth for the test to be valid✓
• d.It is placed in the sterilizer alongside the test indicator

The unprocessed control proves the spore population is viable and that the incubator and reading method are working, so it must turn positive while the processed indicator turns negative. If the control fails to grow, the test result is invalid regardless of what the processed indicator shows. Sterilizing the control defeats its purpose, and it must come from the same lot and be incubated at the same time.AAMI ST79

A sterilizer has just been relocated to a new position in the department. What testing is required before it processes patient loads?

• a.A single Bowie-Dick test on the first day of use
• b.Only a leak test performed by the service technician
• c.No testing, because the sterilizer passed all tests before it was moved
• d.Installation and requalification testing, including three consecutive negative biological indicator cycles in an empty chamber, plus three passing Bowie-Dick tests for dynamic-air-removal sterilizers✓

Relocation, installation, and major repairs all trigger full qualification testing because the utilities, leveling, and connections have changed. The accepted protocol is three consecutive empty-chamber cycles with negative biological indicators, with Bowie-Dick testing added for dynamic-air-removal units. A service leak test or a single daily test is not a substitute for qualification.AAMI ST79

A recall is initiated after a sterilization failure. Which action is part of a proper recall procedure?

• a.Reprocess the affected items and release them without documenting the event
• b.Notify the affected departments verbally and take no further action
• c.Identify every item processed since the last negative biological indicator, retrieve and quarantine them, notify risk management and infection prevention if any were used on patients, and document the investigation and corrective action✓
• d.Retrieve only the items still on the sterile storage shelves

An effective recall traces every package from the affected cycles using load records and lot control labels, pulls them from storage and from the procedural areas, and escalates when items have already been used so patient follow-up can be considered. The event, the root cause analysis, and the corrective actions are documented as part of the quality program. Limiting the search to shelf stock or skipping documentation defeats the purpose of traceability.AAMI ST79

A dynamic-air-removal cycle has just ended and a technician is opening the sterilizer to pull the load. Which practice prevents burns?

• a.Spray the shelves with cool water before unloading so the trays can be handled with bare hands
• b.Open the door fully and pull the loading cart straight out now so the next load can start
• c.Wear heat-protective gloves, stand to one side of the door, and let the heat dissipate first✓
• d.Reach in with a dry cotton towel over each hand, which insulates better than sterilizer gloves

The chamber, the rack, the cart and the packages themselves stay at cycle temperature long after the door unlocks, so heat-protective gloves plus standing clear of the plume of escaping steam are what actually prevent burns. Pulling the cart straight out at once puts hands and forearms against metal that is still near 270 degrees F. Spraying cool water onto the shelves drives condensate into the packages, contaminating them, and can flash to steam in the operator's face. A dry cotton towel gives almost no thermal protection, slips off the hand, and wicks instantly if it touches condensate.AAMI ST79

A continuous ethylene oxide area monitor alarms while a technician is working near the sterilizer. What is the correct response?

• a.Silence the alarm, finish the cycle in progress, and read the dosimeter badge at month's end
• b.Open the sterilizer door part way so chamber gas is drawn into the room exhaust faster
• c.Leave the area at once, keep others out, and notify the supervisor so exposure is evaluated✓
• d.Put on a surgical mask and keep working until the monitor reading falls back to normal

An area monitor alarm means airborne ethylene oxide has reached a level the system is set to warn on, and the gas is a colourless carcinogen that the technician cannot smell at hazardous concentrations. Leaving, restricting access and escalating so the exposure can be measured and the leak found is the required response, and this is one of the few situations where the technician cannot resolve the hazard alone. Silencing the alarm and waiting for a monthly badge reading leaves people breathing the gas for the rest of the shift. Cracking the door releases far more gas into the room. A surgical mask is not respiratory protection and filters no gas at all.OSHA 29 CFR 1910.1047

Why are personal dosimeter badges and area monitors required around an ethylene oxide sterilizer?

• a.Ethylene oxide is a carcinogen, and OSHA sets an exposure limit of 1 ppm as an 8-hour average✓
• b.The badge records chamber humidity so the cycle's 40 to 80 percent range can be documented
• c.Monitoring proves each load received the full aeration time required before items are released
• d.The readings verify room oxygen stays above 19.5 percent because the gas displaces fresh air

Ethylene oxide is regulated as an occupational carcinogen, and the standard sets a permissible exposure limit of one part per million averaged over an eight-hour shift, with a short-term excursion limit as well. Badges measure what an individual worker actually breathed and area monitors detect leaks in real time, which is why both are used. Cycle humidity is controlled and recorded by the sterilizer itself, not by a worker's badge. Aeration time is verified from the aerator's own record and the load documentation. Oxygen displacement is a confined-space concern, not the reason ethylene oxide exposure is monitored.OSHA 29 CFR 1910.1047

What ventilation is required in the room where an ethylene oxide sterilizer and its aerator are installed?

• a.Positive pressure to adjacent areas so escaping gas is pushed out of the equipment room fast
• b.Recirculating charcoal filters that return the cleaned air to the sterile storage area nearby
• c.Dedicated exhaust discharged outdoors, with local capture at the sterilizer door and aerator✓
• d.A ceiling fan aimed across the sterilizer door to dilute gas in the operator's breathing zone

Ethylene oxide installations need dedicated, non-recirculating exhaust that discharges outside the building, with local exhaust capture at the point of release, which is the sterilizer door at the end of a cycle and the aerator, plus an emergency purge capability. Recirculating the air back into the department, and especially into sterile storage, simply moves the gas to where staff and sterile stock are. Positive pressure would push contaminated air out into occupied areas rather than containing it, which is the opposite of what is wanted. A ceiling fan only stirs the gas around the room and does not remove it from the building.AAMI ST41

Halfway through a steam cycle the sterilizer's printer runs out of paper. What should the operator do?

• a.Abort the cycle at once and check with the supervisor before the load is started over again
• b.Let the cycle finish, record the parameters from the display, and add paper before the next✓
• c.Crack the door open at the end of exposure to fit a new roll so the drying phase is printed
• d.Release the load on the internal chemical indicator, which is the legal record of the cycle

Running out of paper is a documentation problem, not a sterilization problem, and the standard already tells the operator what to do: let the cycle complete undisturbed, capture the time, temperature and pressure from the display or the electronic record, document why the printout is incomplete, initial it, and reload the printer before the next load. Escalating instead of recording the data dodges a duty the technician is trained and expected to perform. Aborting a good cycle wastes the load and the sterilizer time for no safety gain. An internal chemical indicator shows exposure to the process but is not the physical monitoring record. Opening the door mid-cycle destroys the load and can burn the operator.AAMI ST79

Which daily task keeps a steam sterilizer's air removal and condensate drainage working properly?

• a.Pouring a chlorine bleach solution down the drain each morning to disinfect the condensate
• b.Leaving the strainer undisturbed until a printout shows a slow exhaust, then replacing it
• c.Removing the strainer so that lint and debris pass directly into the building's drain line
• d.Cleaning the chamber drain strainer of lint and debris on each day the sterilizer is used✓

Air and condensate leave a steam chamber through the drain, and the strainer at that drain traps lint, paper fiber and debris. If it clogs, air cannot be displaced, condensate backs up, and the temperature probe sitting in the drain line no longer reads what the load is experiencing, so daily cleaning per the manufacturer's instructions is standard operator maintenance. Chlorine attacks stainless steel and is not used in the chamber or drain. Waiting until a slow exhaust prints means loads have already run with restricted drainage. Taking the strainer out lets debris reach and foul the trap and drain piping, which is exactly what it is there to prevent.AAMI ST79

How should the interior of a steam sterilizer chamber be cleaned?

• a.With steel wool and scouring powder, which lift hard-water scale off the chamber wall fast
• b.With a diluted sodium hypochlorite solution left to dwell ten minutes to disinfect it
• c.With a cooled chamber and the maker's approved nonabrasive cleaner, then rinsed and dried✓
• d.With the chamber still hot after a cycle, so residual heat helps the cleaner dissolve soil

Chamber cleaning is done on a cool chamber with the cleaning agent the sterilizer manufacturer approves, which is nonabrasive and chloride free, followed by a thorough rinse and wipe dry so no residue is baked onto the walls. Steel wool and scouring powder scratch the passive layer of the stainless steel and leave particles that become sites for corrosion and staining. Sodium hypochlorite contains chloride, which pits stainless steel chambers and fittings. Cleaning a hot chamber flashes the solution to vapor, burns the technician, and leaves streaked deposits rather than removing them.AAMI ST79

Which task belongs to scheduled preventive maintenance rather than to daily operator maintenance?

• a.Calibrating the gauges and recorder and servicing the vacuum pump on the maker's schedule✓
• b.Wiping the door gasket and the outside of the chamber at the start of each working shift
• c.Cleaning the chamber drain strainer and flushing the drain on each day the unit is used
• d.Checking jacket pressure and steam supply pressure before running the first cycle of a day

Preventive maintenance is planned work done on a defined interval by a qualified service technician, and it covers calibration of gauges, recorders and controls, vacuum pump service, valve and trap replacement, and similar tasks that require tools, parts and a service record. Wiping the gasket and exterior, cleaning the drain strainer, and confirming jacket and steam supply pressures before the first cycle are all routine operator duties done every day by the person running the sterilizer. Confusing the two is how departments end up with sterilizers that are wiped down daily but never calibrated.AAMI ST79