Why are blood-soiled instruments first rinsed in cool water rather than hot water?

Hot water coagulates proteins onto surfaces

Cool water sterilises the instruments

Hot water damages enzymatic detergents only

Where should a technician write on a paper-plastic peel pouch?

On the paper side with a ballpoint pen

Inside the pouch on a paper slip

How does saturated steam kill microorganisms?

By denaturing and coagulating proteins

By oxidising cell walls chemically

Which shelving arrangement is appropriate for sterile storage?

Raised off the floor, below sprinklers

On the floor near the entrance door

On top shelves touching sprinklers

What personal protective equipment is required when manually cleaning instruments in the decontamination area?

Fluid-resistant gown, gloves, face shield

Disposable examination gloves only

Cotton apron, cap and shoe covers

Sterile gown with sterile gloves only

A steam load contains orthopaedic implants. When may the load be released for use?

After the BI result is negative

A wrapped tray is found to be wet after the cycle has ended and cooled. What should be done?

Treat it as unsterile and reprocess

Dry it in a warming cabinet and use

Use it if the indicator has changed

How should peel pouches be placed in a steam steriliser?

Packed tightly to fill the chamber

A load has just been removed from the steriliser. How should it be handled?

Cool on the cart away from vents

Store immediately in closed cabinets

The morning Bowie-Dick test sheet shows uneven colour change with a pale centre. What is the correct action?

Withdraw the steriliser and report it

Repeat the test after the first load

Run patient loads but add extra indicators

Use the steriliser for gravity cycles only

A department uses event-related sterility. What determines whether a stored pack is still sterile?

Whether the packaging is intact and dry

The number of times it was moved

A fixed 30-day expiry for all packs

The colour of the internal indicator

Free · 15 questions with answers · every GCC exam

Central Sterile Services Technician Prometric exam questions with answers

15 original practice questions written to the Central Sterile Services Technician exam blueprint, each with the answer and why the other options are wrong. Below them: the Central Sterile Services Technician exam's format, pass mark and fee at DHA, DOH, SCFHS, QCHP and every other GCC regulator, from their own published rules.

15
Free questions: 50%
DHA pass mark: 150
Questions on the DHA exam: 12
Questions in the free mock

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Quick answer

The Central Sterile Services Technician exam is 150 MCQs in 3 hours at DHA (pass mark 50%). Below are 15 original practice questions written to the official blueprint, each with the answer and why the other options are wrong, plus a free 12-question timed mock.

The Central Sterile Services Technician exam in every GCC country

DHA publish an exact Central Sterile Services Technician exam; the others apply one format to every title. Figures come from each regulator's own exam pages - anything not published says so.

Central Sterile Services Technician licensing exam in every GCC country
Regulator	Exam	Format	Pass mark	Fee per attempt	Practise
DHA Dubai	Central Sterile Services (CSS) Technician (STE5652)	150 MCQs in 3 hours	50%	USD 240 (about AED 880)	DHA questions →
DOH Abu Dhabi, Al Ain and Al Dhafra	DOH licensing exam Regulator-wide format	Written + oral/OSCE	Pass / fail only	Not published	DOH questions →
MOHAP Northern Emirates - Ajman, Umm Al Quwain, Ras Al Khaimah and Fujairah	MOHAP licensing exam Regulator-wide format	Computer-based	Not published	Not published	MOHAP questions →
SHA Emirate of Sharjah	SHA licensing exam Regulator-wide format	Set at assessment	Not published	Not published	SHA questions →
SCFHS Kingdom of Saudi Arabia	SCFHS licensing exam Regulator-wide format	200 MCQs, 240 min	500-560 of 800	Not published	SCFHS questions →
QCHP State of Qatar	QCHP licensing exam Regulator-wide format	150 MCQs, 3 hrs	50-65%	Not published	QCHP questions →
NHRA Kingdom of Bahrain	NHRA licensing exam Regulator-wide format	Prometric CBT	Not published	Not published	NHRA questions →
OMSB Sultanate of Oman	OMSB licensing exam Regulator-wide format	Computer-based OC exam	Not published	Not published	OMSB questions →
Kuwait MOH State of Kuwait	Kuwait MOH licensing exam Regulator-wide format	150 MCQs, 170 min	60-70%	Not published	Kuwait MOH questions →

exact exam published for Central Sterile Services Technician

Pass marks, attempts and fees change - confirm yours on the regulator's exam page before you book.

15 Central Sterile Services Technician exam questions with answers

Choose your answer first, then open the explanation. The set covers the main blueprint domains at a mix of easy, medium and hard.

Question 1Decontamination: Cleaning and Disinfectionmedium
How does an ultrasonic cleaner remove soil from instruments?
1. ACavitation of tiny bubbles
2. BHigh-pressure water jets
3. CThermal coagulation of protein
4. DChemical sterilisation
Show answer and explanation
Answer: A. Cavitation of tiny bubbles
High-frequency sound waves create tiny bubbles that implode, a process called cavitation, dislodging soil from crevices and joints. It cleans but does not disinfect or sterilise.
Question 2Decontamination: Cleaning and Disinfectionhard
Why are blood-soiled instruments first rinsed in cool water rather than hot water?
1. AHot water coagulates proteins onto surfaces
2. BCool water sterilises the instruments
3. CHot water damages enzymatic detergents only
4. DCool water dries faster
Show answer and explanation
Answer: A. Hot water coagulates proteins onto surfaces
Water above about 45 degrees Celsius coagulates blood proteins and fixes them to the instrument, making them harder to remove. Cool water keeps proteins soluble for the cleaning stage.
Question 3Inspection, Assembly and Packagingmedium
Where should a technician write on a paper-plastic peel pouch?
1. AOn the paper side with a ballpoint pen
2. BOn the plastic side or a label
3. CAcross the heat seal
4. DInside the pouch on a paper slip
Show answer and explanation
Answer: B. On the plastic side or a label
Labelling is done on the plastic side or on a label so that ink does not penetrate or damage the paper barrier. Writing across seals can compromise their integrity.
Question 4Low-Temperature Sterilisationmedium
Which packaging material is unsuitable for hydrogen peroxide gas plasma sterilisation?
1. ACellulose paper or linen
2. BPolypropylene wrap
3. CTyvek-plastic pouches
4. DValidated rigid containers
Show answer and explanation
Answer: A. Cellulose paper or linen
Cellulose materials such as paper and linen absorb hydrogen peroxide and can cause cycle failure. Polypropylene wraps and Tyvek pouches are compatible.
Question 5Steam Sterilisationeasy
How does saturated steam kill microorganisms?
1. ABy oxidising cell walls chemically
2. BBy denaturing and coagulating proteins
3. CBy dehydrating spores slowly
4. DBy damaging DNA with radiation
Show answer and explanation
Answer: B. By denaturing and coagulating proteins
Moist heat transfers energy rapidly as steam condenses, causing irreversible denaturation and coagulation of microbial proteins. Dry heat works more slowly by oxidation.
Question 6Microbiology and Infection Prevention Principlesmedium
Which of the following is most resistant to chemical disinfectants and heat?
1. AEnveloped viruses
2. BMycobacteria
3. CBacterial spores
4. DVegetative bacteria
Show answer and explanation
Answer: C. Bacterial spores
Apart from prions, bacterial spores are the most resistant to disinfection and sterilisation, followed by mycobacteria. Enveloped viruses such as HIV are among the easiest to inactivate.
Question 7Sterile Storage and Distributionhard
Which shelving arrangement is appropriate for sterile storage?
1. AUnder the sink for easy access
2. BOn the floor near the entrance door
3. COn top shelves touching sprinklers
4. DRaised off the floor, below sprinklers
Show answer and explanation
Answer: D. Raised off the floor, below sprinklers
Sterile items are stored 8 to 10 inches (about 20 to 25 cm) above the floor and 18 inches (about 45 cm) below the ceiling or sprinklers, away from water sources. Floor and under-sink storage risk contamination.
Question 8Workplace Safety and Professional Conducteasy
What personal protective equipment is required when manually cleaning instruments in the decontamination area?
1. ADisposable examination gloves only
2. BFluid-resistant gown, gloves, face shield
3. CCotton apron, cap and shoe covers
4. DSterile gown with sterile gloves only
Show answer and explanation
Answer: B. Fluid-resistant gown, gloves, face shield
Manual cleaning creates splashes, so staff wear a fluid-resistant gown, heavy-duty gloves, and eye and face protection such as goggles with a mask or a face shield. Gloves alone leave the face and body exposed.

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Question 9Monitoring, Quality Assurance and Traceabilitymedium
A steam load contains orthopaedic implants. When may the load be released for use?
1. AAs soon as the cycle ends
2. BAfter the BI result is negative
3. CWhen the external tape changes
4. DAfter the load has cooled
Show answer and explanation
Answer: B. After the BI result is negative
Loads containing implants should be monitored with a biological indicator and quarantined until the result is negative. Early release is limited to documented emergencies.
Question 10Steam Sterilisationmedium
A wrapped tray is found to be wet after the cycle has ended and cooled. What should be done?
1. ATreat it as unsterile and reprocess
2. BDry it in a warming cabinet and use
3. CUse it if the indicator has changed
4. DOpen it and wipe the moisture
Show answer and explanation
Answer: A. Treat it as unsterile and reprocess
Moisture can wick microorganisms through the packaging, so wet packs are considered contaminated and must be reprocessed, and the cause investigated. A changed indicator does not overcome this.
Question 11Steam Sterilisationmedium
How should peel pouches be placed in a steam steriliser?
1. AOn edge, paper facing plastic
2. BFlat and stacked on each other
3. CUnder heavy metal trays
4. DPacked tightly to fill the chamber
Show answer and explanation
Answer: A. On edge, paper facing plastic
Pouches are placed on edge in a rack, paper side to plastic side, so steam can penetrate and condensate can drain. Stacking flat or overloading traps air and causes wet packs.
Question 12Steam Sterilisationmedium
A load has just been removed from the steriliser. How should it be handled?
1. ACool quickly under an air vent
2. BPlace on a cold metal surface
3. CStore immediately in closed cabinets
4. DCool on the cart away from vents
Show answer and explanation
Answer: D. Cool on the cart away from vents
Loads should cool on the cart in a low-traffic area away from air vents, untouched, to prevent condensation forming inside packs. Cold surfaces and air currents cause condensation and possible contamination.
Question 13Steam Sterilisationmedium
The morning Bowie-Dick test sheet shows uneven colour change with a pale centre. What is the correct action?
1. ARepeat the test after the first load
2. BRun patient loads but add extra indicators
3. CWithdraw the steriliser and report it
4. DUse the steriliser for gravity cycles only
Show answer and explanation
Answer: C. Withdraw the steriliser and report it
A pale centre indicates inadequate air removal or air leak, so the steriliser must not be used for porous loads until fixed and retested. Running patient loads risks non-sterile items.
Question 14Sterile Storage and Distributionmedium
A department uses event-related sterility. What determines whether a stored pack is still sterile?
1. AThe number of times it was moved
2. BA fixed 30-day expiry for all packs
3. CThe colour of the internal indicator
4. DWhether the packaging is intact and dry
Show answer and explanation
Answer: D. Whether the packaging is intact and dry
Under event-related sterility, a pack remains sterile unless an event such as tearing, wetting or crushing compromises the barrier. Handling should be minimised, but time alone does not make it unsterile.
Question 15Workplace Safety and Professional Conductmedium
A technician opening a returned tray finds a loose scalpel blade among the instruments. What is the safest approach?
1. ALift it out with an instrument
2. BPick it out carefully by hand
3. CLeave it in for the washer
4. DReturn the tray unopened
Show answer and explanation
Answer: A. Lift it out with an instrument
Loose sharps should be removed with an instrument, never fingers, placed in a sharps container, and the incident reported so theatre practice can improve. Leaving it risks injury to the next handler.

What the Central Sterile Services Technician exam covers

The blueprint groups questions into these domains. Weight your revision the same way - the heavier domains carry more of your score.

Microbiology and Infection Prevention Principles

~10%

Chain of infection and standard precautions · Spaulding classification · Hierarchy of microbial resistance to disinfection and sterilisation

Decontamination: Cleaning and Disinfection

~18%

Manual cleaning · Detergents · Ultrasonic cleaning and cavitation

Inspection, Assembly and Packaging

~15%

Inspection with lighted magnification and function testing · Insulation testing of laparoscopic instruments · Instrument lubrication and care

Steam Sterilisation

~18%

Principles of moist heat sterilisation · Gravity displacement vs pre-vacuum cycles · Time and temperature parameters

Low-Temperature Sterilisation

~10%

Ethylene oxide · Hydrogen peroxide gas plasma and vapour systems · Material and packaging compatibility

Monitoring, Quality Assurance and Traceability

~14%

Physical monitoring · Chemical indicator types and classes · Biological indicators and process challenge devices

Sterile Storage and Distribution

~7%

Event-related sterility and shelf life · Storage conditions · Stock rotation and inventory management

Workplace Safety and Professional Conduct

~8%

Personal protective equipment in the decontamination area · Sharps safety and injury reporting · Chemical safety

How to answer these questions

Questions test applied practice: what you would do with this patient, this result or this image - not textbook definitions.

Safety items (radiation, infection control, patient identification, equipment checks) are high-yield and quick to revise.

Under time pressure, flag and move on: every question carries the same mark.

Aim to score comfortably above your regulator's pass mark - 10 to 15 points of margin - on timed, full-length practice before you book.

Central Sterile Services Technician exam questions: FAQs

How many questions are in the Central Sterile Services Technician Prometric exam?

It depends on the regulator: DHA 150 MCQs in 3 hours. The full table above lists every GCC regulator.

What is the pass mark for the Central Sterile Services Technician exam?

DHA: 50%. Pass marks are set exam by exam, so use your own regulator's figure.

Are these real exam questions?

No. Regulators do not release their papers, and anything sold as a leaked paper is unofficial and risky to rely on. These are original questions written to the official exam blueprint, at the level and in the style of the real exam, each with a worked explanation.

Is the Central Sterile Services Technician exam the same in every GCC country?

The clinical content is broadly similar because the exams test the same safe practice, but the format, length, pass mark, attempts and fees differ by regulator. Prepare on the content once, then check your regulator's exact rules before you book.

How should I use these questions?

Answer each one before opening the explanation, and note why each wrong option is wrong. Then take the free 12-question timed mock to see your score against the pass mark, and move to full-length papers when you score comfortably above it.

Last reviewed September 2026. Questions are original and written to the published exam blueprint; they are not taken from any real paper.

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