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It is not possible to individually control each medical device being reprocessed. Instead, each reprocessing step (from point of use processing to aseptic presentation) undergoes validation to minimize the risk of a non-sterile product.
Initial validation takes place before a new process or equipment is implemented. Revalidation ensures that process effectiveness is maintained over time. It takes place periodically (often annually) or after a major event (for example, voluntary modification or breakdown)
Between validations (initial validation and revalidation) periodic or systematic routine controls preserve process effectiveness over time.
The validation plan defines the operations, methods and schedules of the initial validations, revalidation and routine controls as well as the responsibilities, training and, as needed, accreditations of the personal in charge.
Validation includes the qualification of the equipments used by the process. Qualifications of equipment consist of installation qualification (IQ) , operational qualification (OQ) ,performance qualifications (PQ) and requalifications (rQ).
In the present guidelines it will be considered that all processes, including those predominently manual, require equipment (for example a bench with sink possibly equipped with pumps for manual cleaning) and will hence consist of IQ, OQ, PQ. Validation of manual processes such as point of use processing or manual cleaning is key to minimize human dependance. Risks of deviance is however inevitably be higher than for a validated automated process
Installation qualification (IQ) is intended to confirm that the services associated with the equipment (water, electricity, etc.) and any accessories and safety devices are installed in accordance with the manufacturer’s instructions.
Documentary verification may be considered as a prerequisit to qualification operations or as being part of IQ.
The documents to be made available by the manufacturer vary according to the type of equipment but have some common points. Before installation, the supplier:
In return, the future user specifies any installation constraints (eg quality of the water available), the requirements in terms of the test method to be used. After installation, the user checks:
Language in which the user and service manual must be made available is defined by local regulation. |
Operational qualification (OQ) is carried after successful IQ. It is intended to verify that the equipment performs according to manufacturer design specifications and international standards respectively. OQ tests are performed with empty equipment or test loads.
Additionally, the calibration status of all instruments (including test instruments) used for monitoring, control, indication or recording should be confirmed.
Performance qualification (PQ) takes place after successful IQ and OQ on an equipment in normal operating conditions. All factors that may have an influence (operators, methods, materials and the environment) should be taken into account.
Requalification is usually performed annually periodically or earlier in case of an event that may affect the efficacy of the process.
Examples of events justifying a requalification: • Change in equipment and installation that may impact process performance (e.g. modification of cycle parameters, new load carriers or cleaning products). • New load, unless it has been shown to be equivalent to another load already validated. • Failure detected during a routine control • Relocation of the equipment or technical intervention with change of critical elements in the PLC (or intervention on control elements) |
The contents of the initial IQ, OQ and PQ and scheduled requalifications are predefined. Scheduled requalifications may be simplified compared to initial qualifications (for example IQ will not be repeated).
The content of the unscheduled validation is event related (for example IQ may be partially or totally repeated after a relocation of the equipment).
Validation and requalifications operations are supervised by the sterilization department or the technical department of the healthcare facility. The healthcare facility may however contract with the supplier of the equipment or third parties. A detailed written description of the scope, objectives and respective assignments must be made produced.
In practice IQ is performed by the supplier of the equipment (manufacturer or distributor) or a service provider accredited by the supplier. Some or all OQ operations may be performed by the user, by a qualified third party or by the supplier as part of a service contract (or a service provider accredited by the supplier) |
International standards do not assign responsibilities but they say that the responsibilities and party accepting the responsibilities must be defined and recorded.
Validation and requalification reports are approved and kept for record by the healthcare facility.They are grouped in a process validation report confirming:
- The existence of up-to-date procedures,
- The availability of up-to-date documentation
- The existence of a validation plan and its execution.
for equipment, the validation (or revalidation) report includes
the approval of the validation. |
- Cleaning processes can be automated (with washer-disinfectors), manual or assisted by ultrasonic cleaners. Validation (IQ, OQ, PQ) of processes in automated washer-disinfectors is performed according to ISO 15883-12 and subsequent parts 3,4,5,6,7
- There is no ISO standard for manual cleaning and ultrasonic cleaners but ISO 15883-1 principles may be applied.
The validation of Automated Endoscope Reprocessor will be added in a future update of the guidelines. Washer-disinfector includes a disinfection phase, which in some case
The validation of Automated washer-Disinfector includes the validation of a disinfection stage (thermal or chemical). For some devices the disinfection stage might be the last step before use
Some local guidelines say that validation of Washer-Disinfector complying to ISO 15883-6 and ISO 15883-7 can be simplified as they pertain to non-critical items
IQ verifies that the connections and utilities (power, water, drain, dosing systems etc..) and Washer disinfector, ultrasonic bath or manual cleaning workstation are installed according to manufacturer specifications, that the equipment is safe for use and that equipment and consumables documentation is available.
OQ verifies that the equipment operates as specified by the manufacturer (for example, absences of leaks, chemistry dosing, temperature for thermal washer-disinfector, cavitation for ultrasonic baths, drying). Cleaning test are performed with test soils.
Controls are visual for visible surface and quantitative (e.g. protein tests) for complex device with hidden surfaces. Test methods, test soils and acceptance criteria are described in ISO 15883-58 (see below)
PQ is intended to control that reproducible results are obtained in conditions fully representative of real life. Control tests are performed with actual loads or devices contaminated by clinical use. Validated surrogate devices and test soils may however be used when real devices are difficult to sample.
Prior to PQ, load or devices are grouped in families presenting common processing characteristics. Load or device used for PQ are selected to present the highest cleaning challenge for a given family.
Controls are visual for external surface, carriers and loads and quantitative for complex devices with hidden surfaces. Test methods, test soils and acceptance criteria are described in ISO 15883-5,8 (see below)
The 2005 version of ISO 15883-5 listed soils and test methods developped by different countries. ISO 15883-5 ( 2021), lists chemical substance (analytes) contained in artificial or clinical soils.
Analytes (for example protein) shall be used for quantitative control of cleanliness. For each analytes alert levels and action levels are provided (for exemple 3 μg/cm2 and 6,4 μg/cm2. Respectively for protein). The alert level provides early warning of a deviation. The action level necessitates immediate action. Annex C of ISO 15883-5 describes methods (modified OPA, BCA) which may be used to sample the device and measure residual protein. Test soils must contain a quantity of analyte representative of clinical soils. Examples of test soils are provided for various applications (for example coagulated blood for general surgery). Examples of analytes with corresponding alert and action levels are displayed below
Example of test soils (coagulated blood, 2 components blood test, Edinburgh, ATS2015, BTS, biofilm) for various procedures (general surgery, gastroinstestinal, flexible endoscopy) are provided in annex A of ISO 15883-5 |
The contents of the initial IQ, OQ and PQ and scheduled requalifications are predefined.
Operational and Performance requalifications are commonly annual. Scheduled requalifications may be simplified compared to initial qualifications.
Scheduled requalifications may be simplified compared to initial qualifications. For example some national guidelines may suggest to test the most challenging program and load carrier configurations instead of testing all program/load configurations.
The content of the unscheduled validation is event related (for example IQ may be partially or totally repeated after a relocation of the equipment).
Routine controls include periodic tests (part of OQ or PQ) and systematic controls (each cycle) Validation of Automated Washer-Disinfector processes consist of IQ, OQ and PQ as defined by ISO 15883-1 and annexes applicable to the specific type of washer-disinfector (Thermal or chemical, critical and semi-critical or non critical devices). Tests applicable to automated endoscope reprocess will be added in a future update of WFHSS guidelines.
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Annex B of ISO 15883-1 explains the A0 concept.
A0 is the equivalent value in seconds at 80 ° C to produce a given disinfection effect on a specified microorganism. When the microorganism is a bacterial spore (the most resistant) we speak of A0. A0 = ∑ 10 ((T - 80) / Z) ∆t T is the temperatureZ is specific to each microorganism. The Z value indicates the increase in T ° C allowing to accelerate the reduction of the population by a factor of 10 (in other words a change in the D of the microorganism by a factor of 10). For bacterial spores the z is 10 ° C.∆ t is the holding time at a temperature ≥ TStandard ISO 15883-1 imposes a minimum A0 of 600 s corresponding to 10 min at 80 ° C or 1 min at 90 ° C. It adds that any washer-disinfector must offer at least one cycle capable of achieving an A0 of at least 3000 s (i.e. 5 minutes at 90 ° C, 2 mins 30 at 93 ° C).The recommendations of the standard on the positioning of sensors are detailed below: |
ISO 15883-1 recommends to perform thermometric and cleaning efficiency controls for each cycle and type of carriers. This represents a large number of tests. Simplifications might be considered after appropriate risk analysis or per national guidance. ISO 15883-1 is being adapted according to ISO 15883-5 and recent evolution. As experience is acquired with the new standard framework, adaptations may be proposed by local guidelines
Local regulations may impose some specific requirements. For example UK and Austria have defined cleaniless target per device, instead of per cm2 An example of Manual cleaning processes validation inspired by ISO 15883-1 and ISO 15883-5 principles may be as follows
The “guideline for validation of manual cleaning and manual chemical of medical devices” 9 published in Germany is an example of a validation plan for manual cleaning processes
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Validation of ultrasonic cleaning bath must be adapted to the use of the type and objective of the ultrasonic cleaning process.
- If the ultrasonic bath is used in preparation to Manual cleaning, it will be considered as a preparation to manual cleaning process and cleaning efficacy control do not have to be performed.
- If the ultrasonic bath is the final stage before dsinfection or sterilization of the Medical device the procedure shoud be according to ultrasonics system features.
In all cases cavitation efficacy should be controlled
Cavitations test can be performed using:
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An example of ultrasonic cleaning processes validation inspired by ISO 15883-1 and ISO 15883-5 principles may be as follows
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Packaging validations is governed by standards ISO 11607-110 (packaging system), 11607-211 (packaging process) and guided by ISO 1677512
ISO 11607-2 concerns packaging processes such as forming, sealing and assembly of preformed sterile barrier systems, sterile barrier systems and packaging systems. ISO 16775 provides guidance on ISO 11607-1 and -2 and suggests validations plans and checklists for each type of packaging (wraps, pouches and reels and containers).
The packaging validation plan lists the types of packaging and packaging equipment and determines, for each type of packaging (wraps, pouches, reels, containers), those that will be subject to validation.
The installation qualification (IQ) controls that:
- The packaging workstations and environment are adequate: layout, ergonomics (operator position), light appropriate for visual controls, air quality, temperature and humidity level,
- The documentation is available for each type of packaging (brand, model): user documentation, marking and certificates of compliance with applicable standards, compatibility with the sterilization cycle planned for the DMR, storage conditions.
- Maintenance plans are in place for equipment, in particular heat sealers.
- Operating procedures are available for each type of packaging and operator training are up to date. Cleaning and disinfection procedures are in place for the workstations and environment.
The user is not expected to repeat the type tests already performed by the manufacturer. Instead, certificates of compliance to the tests listed in the appendix to NF EN ISO 11607-1 and recommended by the applicable NF EN 868 standard should be requested (867-213 for wraps, 867-514 for Pouches and reels, 867-813 for containers). The chemical indicators affixed to the packaging should comply with NF EN ISO 11140-1.
The operational qualification (OQ verifies the correct implementation of various packaging, controls that heat sealers meet manufacturer specifications and control containers are operational and were maintained according to plans. PQ test are performed with the most challenging load for each type of packaging.
For wraps: controls of correction execution
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The performance qualification controls the entire packaging circuit from preparation to aseptic presentation (article 6.3 ISO 11607-1 January 2018)). Performance validation is performed with performed with actual content representing the most challenging packaging and handling, transport and storage conditions. It confirms, through practice, the risk analyzes carried out when defining the packaging system suitable for each RMD or family of DMRRMD’s.
Within each family of packaging (sheets, sachets / sheaths, containers) several variants, specific to each hospital, may exist (according to the type of DMR, sterilization methods, size, brand etc…) . In practice, it is accepted to limit operational and performance validations after apropriate risk analysis. ISO 16775 provide guidance to determine the size of OQ samples. ISO 16775 suggests 3 evaluations for each type of packaging (i.e. 3 loads and 3 sterilization cycles. One of them corresponds to the conditions considered to be the most penalizing. If destructive checks are carried out (dye test or peel test), the number of samples tested is increased accordingly.
Requalification is annual. It may be simplified compared to the initial validation. A risk analysis will determine if a requalification is required after an incident or a voluntary modification (e.g. change of supplier).
Routine and periodic tests include:
- systematic visual checks of packaging, before sterilization, after sterilization and before opening
- periodic checks of the execution quality of packaging systems and in particular checks on the effectiveness of the seals
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Validation of steam sterilization process is carried out according to ISO 17665-114 and guided by ISO 17665-215 and ISO 17665-316
ISO 17665-1 specifies the implementation requirements for large steam sterilizers. Technical specification ISO 17665-2 provide guidance for implementation of ISO 17665 -1. Technical specification ISO 17665-3 provide guidance to assign device in product families presenting common characteristics. These 3 texts refer to the criteria and test methods applicable to steam sterilizers complying to EN 28517.
ISO 17665-1, -2 and -3 cover hospital and industry applications of steam sterilization. Annex D of EN ISO 17665-2 refers to considerations specific to healthcare establishments.
ISO 17665-1 can also be used, by analogy, for small steam sterilizers conforming to standard EN 1306018 (sterilizers intended for loads smaller than one sterilization unit)
IQ verifies and documents the compliance of the services (water supply, steam supply if applicable, power, supporting structure, etc.) with the manufacturer’s specifications. IQ also checks the availability of documentation (Instruction for use, maintenance, calibration certificates, certificates of essential type tests) as well as statement of conformities to local, regional, or national regulations for emissions into the environment from the equipment. The installation and documentation checks may need to be repeated, in part, after risk assessment, after a relocation of the equipment or a major modification / repair to the installation.
Paragraph 24 of EN 285 defines the documentation to be supplied with the sterilizer (measurement system calibration certificate, proof of control of the safety functions, settings of the automatic control device, declaration of compliance with standards). Paragraph 25 of EN 285 lists the information required to prepare the installation, operate the sterilizer and ensure routine maintenance. It details the information to be communicated before installation (25.2), upon delivery (25.3) and before installation qualification (25.3). Local regulation define safety measure and periodic inspection against the risk related to te safety of pressure vessels
OQ verifies that the equipment operates as specified by the manufacturer: OQ tests include steam quality, air leakage flow rate, thermometric test, air detector if fitted, steam penetration, load dryness, thermometric tests hollow load and Bowie-Dick test,
PQ is intended to control that reproducible results are obtained in conditions representative of real life.
Thermometric tests are performed with the most challenging load among product families and loading configurations that the sterilizing process may treat.
Advice on characterizing for difficulty should be available from the medical device manufacturer(s) and/or sterilizer manufacturer. Element to be considered when defining the most challenging load are mass (tray or container with the highest mass, the material and geometry (hollow devices), packaging (wrap, pouches, container).
Experience has shown that for a typical health care sterilization load and chamber usable space (ca. 400 l), 5 to 12 temperature sensors may be sufficient. Some sensor are placed on parts of the medical device from which is assumed (or known) that stelm penetration/air removal is most difficult to achieve.
If a process challenge device is used the challenge must be equivalent to the medical device(s).
Operational and Performance requalifications are commonly annual. The contents of the initial IQ, OQ and PQ and scheduled requalifications are predefined.
The content of the unscheduled validation is event related (for example IQ may be partially or totally repeated after a relocation of the equipment or a major repair).
Other examples of event requiring a requalification are a modification of the sterilization program or packaging A revalidation may be required (for example, modification of the pre-treatment or sterilization phase, change of the duration), after modification of a packaging. Following a load modification, revalidation can be avoided if it has been shown that the new load is equivalent to another load already validated.
Routine controls are performed at each cycle, daily, weekly or quarterly
- Each cycle: dryness and integrity of all packaging and chemical indicators (if used). Control that cycle parameters are in accordance with validation data.
- Daily: visual control of corrosion and stain in chamber, gaskets, control of operating means and recorders, Bowie Dick test (chemical or electronic)
- Weekly: Air leakage flow rate in some countries and calibration of air detector (if fitted)
- At least quarterly: Air leakage flow rate (if not specified by country guidelines and unless the sterilizer is fitted with an automated leak tests active at each cycle)
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in waiting for the development of ISO and EN vH2O2 standards , ISO 149371 and ISO 11138-120 remains the references for the validation of vH2O2 processes.
3 vH2O2 standards are currently in development. ISO 22441: Sterilization of health care products – Low temperature vaporized hydrogen peroxide – Requirements for the development, validation and routine control of a sterilization process for medical devices” will have the same structure as ISO 14937. Links will be made to EN 17180 “sterilizers for medical purposes – low temperature vaporized hydrogen peroxide sterilizers-requirements and testing” the future vH2O2 standard for manufacturer of H2O2 sterilizers. EN17180 will use the structure of ISO 22421(not to be mixed with ISO 22441) . ISO 11138-6: Sterilization of healthcare products – biological indicators – Part 6 – biological indicators for hydrogen peroxide sterilization processes” will confirm Geobacillus Stearothermophillus will remain the reference test microorganisms for hospital applications. Both ISO 22441 and EN 17180 drafts have agreed on the minimal variables to be measured by a vH2O2 process: Pressure, Time, Temperature and vH2O2 concentration. vH2O2 concentration can be measured by an H2O2 or deducted by other means such as pressure dynamic.
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WFHSS key recommendations for cleaning & disinfection
- As sterility of each RMD cannot be individually controlled, the validation of all reprocessing steps (from point of use cleaning to storage) is essential to minimize the risk of a non sterile device. The validation is a key component of the quality management system.
- International ISO standards detail the validation of automated cleaning and disinfection and most sterilization processes. Although no standardized guidance is provided for manual processes, they must also be validated. The validation manual cleaning process may follow the principles of washer-difector standards.
- A validation plan describes the initial validation (for a new process or equipment), requalifications and routine controls. Initial validation consists of installation qualification (IQ), operational qualification (OQ) and performance qualification (PQ). Requalifcation (rQ) is usually annual. It may be simplified compared to initial validation (for example no need for an rIQ). The content of unscheduled requalification are event related.
- Requalification may be required after an event (for example, relocation of an equipment, amajor change in the process or major repair). The content of the requalification is event related.
- The results of the qualifications are recorded in the validation reports submitted for formal approval.
Validation of all steps of the sterilization processes from point of use processing to aseptic presentation is key to minimize the risk of a non sterile RMD
Go to WFHSS Recommandations for process validation →
1 of 5 Validation of Steam sterilizationFor an example of validation of sterilization process
Go to Validation of steam sterilization →
For details on validations on packaging process
Go to Validation of packaging process →
3 of 5 Process validationFor generale explanation on principles of validations
Go to Principles of validations →
4 of 5 Validation of cleaning processFor details on validations on automated manual and ultrasonic assisted cleaning process
Go to Validation of cleaning process →
5 of 5- ISO 14937: Sterilization of health care products – General requirements for characterization of a sterilizing agent and the development, validation and routine control of a sterilization process for medical devices – 2009
- ISO 15883-1 : Washer-disinfectors — Part 1: General requirements, terms and definitions and tests (2006)
- ISO 15883-2 : Washer-disinfectors — Part 2: Requirements and tests for washer-disinfectors employing thermal disinfection for surgical instruments, anaesthetic equipment, bowls, dishes, receivers, utensils, glassware, etc. (2006)
- ISO 15883-3 : Washer-disinfectors — Part 3: Requirements and tests for washer-disinfectors employing thermal disinfection for human waste containers (2006)
- ISO 15883-4 : Washer-disinfectors — Part 4: Requirements and tests for washer-disinfectors employing chemical disinfection for thermolabile endoscopes (2018)
- ISO 15883-6 : Washer-disinfectors — Part 6: Requirements and tests for washer-disinfectors employing thermal disinfection for non-invasive, non-critical medical devices and healthcare equipment (2011)
- ISO 15883-7: Washer-disinfectors — Part 7: Requirements and tests for washer-disinfectors employing chemical disinfection for non-invasive, non-critical thermolabile medical devices and healthcare equipment (2016)
- ISO 15883-5: Washer-disinfectors — Part 5: Performance requirements and test method criteria for demonstrating cleaning efficacy (2021)
- Guideline for validation of manual cleaning and manual chemical disinfection of medical devices – DGSV/DGKH/AKI (2013)
- ISO 11607-1: Packaging for terminally sterilized medical devices – Part 1: Requirements for materials, sterile barrier systems and packaging systems (2019)
- ISO 11607-2: Packaging for terminally sterilized medical devices — Part 2: Validation requirements for forming, sealing and assembly processes (2019)
- ISO/NP TS 16775 : Packaging for terminally sterilized medical devices — Guidance on the application of ISO 11607-1 and ISO 11607-2
- EN 868 2 to 10 Packaging for terminally sterilized medical devices – Part 2 to 10.
- ISO 17665-1: Sterilization of health care products – Moist heat – Requirements for the development, validation and routine control of a sterilization process for medical devices – 2006
- ISO 17665-2: Sterilization of health care products – Moist heat – Part 2: Guidance on the application of ISO 17665-1 – 2009
- ISO 17665-3: Sterilization of health care products – Moist heat – Part 3: Guidance on the designation of a medical device to a product family and processing category for steam sterilization – 2013
- EN 285: Sterilization – Steam sterilizers – Large sterilizers – 2016
- EN 13060: Sterilization – Steam sterilizers – Small steam sterilizers – 2018
- ISO/TS 22421: Sterilization of health care products — Common requirements for sterilizers for terminal sterilization of medical devices in health care facilities (2021)
- ISO 11138-1 Sterilization of health care products — Biological indicators — Part 1: General requirements (2017)
