Sterilization is crucial in industries like healthcare and pharmaceuticals, and chemical indicators play a pivotal role in ensuring its effectiveness. Discover the world of class 6 indicators, the gold standard for monitoring steam sterilization processes. These indicators provide visual confirmation that sterilization conditions have been met, offering peace of mind and patient safety.
But what sets class 6 indicators apart? They are designed to meet strict industry standards and regulatory requirements, ensuring compliance with sterilization guidelines. By using class 6 indicators, healthcare facilities can optimize their sterilization processes, identify deviations early on, and make necessary adjustments.
To maximize their effectiveness, proper placement and regular monitoring are essential. And while class 6 indicators offer a high level of assurance, they should be used alongside other monitoring methods for comprehensive sterilization validation.
Guideline recommendations for choose chemical sterilization indicators
Introduction to sterilization and the importance of indicators chemistry
Sterilizationis a critical process in various industries, including healthcare, pharmaceuticals, and food production. It involves eliminating all forms of microbial life, including bacteria, viruses, and spores, from equipment, instruments, and surfaces. Sterilization assurance is of utmost importance to maintain safety and prevent the spread of infections.
One essential aspect of sterilization is the use of indicators. So, what does an indicator do?
Types of chemical indicators
The chemical indicators for sterilization or sterilizer indicators systems according ISO 11140 are for use in three main applications:
a) to allow differentiation between unprocessed and processed items;
b) in specific tests and/or procedures, e.g. the Bowie-Dick test; device validation, like Helix tests
c) placement inside individual load items in order to assess attainment of the process parameter(s) and attainment of the respective parameter(s) at the point of placement.
The six indicator types described in ISO 11140 are categorized according to their performance requirements. Table 1 describes three categories according to their intended use.
The chemical indicators within each of these categorizations are further subdivided by the sterilization process for which they are designed to be used. These categorizations have no hierarchical significance.
Attainment of the chemical indicator’s end point not be regarded as an indication of attainment of an acceptable sterility assurance level, but rather one of many factors which should be taken into consideration when judging the acceptability of a sterilization process.
Terms and definitions. For the purposes of this topic, the following terms and definitions apply
What are sterility indicators?
- Sterility Indicator
- combination of the indicator agent and its substrate that reveals change in one or more process variables based on a chemical or physical change resulting from exposure to a process.
- Stated value (SV)
- value or values of a critical process variable at which the indicator is designed to reach its endpoint as defined by the chemical indicator strip manufacturer
- Saturated steam
- water vapor in a state of equilibrium between condensation and evaporation.
- Endpoint
- point of the observed change defined by the indicator manufacturer, occurring after the indicator has been exposed to specified stated values
Table 1 — Categories according to intended use
| # | Intended use | Type (Class indicators sterilization) | Category | Description (intended use) | |
|---|---|---|---|---|---|
| 1 | Indicate exposure to a process to allow differentiation between unprocessed and processed items, and/or indicate gross failure of a sterilization process. Mostly apply on sterilization pouches or sterilization wraps. Use in autoclave tape and sterilization labels | 1 | e1 | “Exposure” or process indicator. Requirements according to Type 1 | |
| 2 | Indicators for use in special applications, e.g. Bowie and Dick-type test., load release indicators | 2 | s2 | “Special” indicator (e.g. Bowie- Dick). Requirements in accordance with ISO 11140-3, ISO 11140−4, and ISO 11140−5. | |
| 3 | Indicators to be placed inside individual load items and to assess attainment of the critical process variables at the point of placement for sterilization monitoring. | This indicator only reacts to one critical process variable. | 3 | i3 | “Internal” indicator. Single variable indicator. Requirements according to Type 3 |
| This indicator reacts to more than one critical process variable. | 4 | i4 | “Internal” indicator Multivariable indicator. Requirements according to Type 4 | ||
| This indicator reacts to all critical process variables in sterile cycle. | class 5 chemical indicator | i5 | “Internal” indicator, Integrating indicator. Requirements according to Type 5 | ||
| This class 6 indicator reacts to all critical sterilization parameters. | class 6 chemical indicators | i6 | “Internal” indicator, Emulating indicator class 6; Requirements according to Type 6 | ||
Type 6: emulating indicators
An emulating indicator designed to react to all critical process variables for specified sterilization processes. The SVs are generated from process variables of sterilization processes as specified in International Standards ISO 11135, ISO 11137 (all parts) and ISO 17665 (all parts), or by regulatory agencies
Understanding class 6 indicators for sterilization
Class 6 indicators for sterilization are designed to monitor steam sterilization processes. They are classified according to the ISO 11140-1 standard, which provides guidelines for the performance of chemical indicators. Class 6 steam indicator strips are considered the most stringent and reliable indicators for steam sterilization, providing a high level of assurance that the sterilization process has been effective.
How chemical indicator class 6 work
Class 6 indicators work by responding to specific physical or chemical changes that occur during the sterilization process. These changes may include exposure to heat, pressure, or specific sterilizing agents. When the sterilization conditions are met, the indicator undergoes a visible change, indicating that the process has been successful.
Professional guidelines INFORMATION
The instruction applies to disposable autoclave chemical indicator for monitoring steam sterilization processes manufactured by Mediwish Co., Ltd, designed to ensure operational visual control of compliance with the parameters of modes and conditions of steam sterilization according to class 6 of ISO 11140-1-2014 in steam sterilizer chambers with a fore-vacuum method for removing air from sterilization chamber.
Class 6 indicators are especially necessary when monitoring the sterilization of materials and medical devices on not new equipment, when using instruments during extensive operations, in particular, in transplantology, during operations in immunocompetent patients, in oncology and burn departments, in AIDS patients and others. cases where absolute quality assurance of sterilization is required with a Sterility Assurance Level (SAL) of ≥10-6
DESCRIPTION steam indicator strip
Emulating chemical indicator, type 6 is performing very precisely for color-change in accordance with such three parameters as time, steam, and temperature covering 121ºC15 min. 135ºC 3.5 min. up to141ºC. The color-·sharp change is from yellow to blue or pink to violet. Indicator enables to estimate aseptic guarantee level: by presuming the exposure condition of saturated vapor under measurement of precise sharp color-difference. Delicate color-difference on plastic film laminated appears precisely as follows in accordance with all critical parameters. Standard version is a laminated indicator without an adhesive backside.
What is a chemical indicator used for?
The indicator is intended for professional users - personnel of medical institutions, workers of disinfection and sanitary-epidemiological services, as well as other organizations and institutions entitled to carry out disinfection activities during operational visual control of the parameters of modes and conditions of steam sterilization in sterilizers with a fore-vacuum method for removing air from the sterilization chamber that meet the requirements EN 285 “Steam large sterilizers. General technical requirements and test methods”; EN 13060 “Small steam Sterilizers”. Indicators allow you to identify deviations from all critical variables (sterilization temperature, sterilization holding time, the presence of saturated water vapor) in the tolerances of critical variables according to class 6 of ISO 11140-1-2014, caused by:
- the presence of air inside the sterilized pouches, packages;
-insufficient duration of the dynamic air removal phase, lack of tightness (air leakage) of the sterilizer in the dynamic air removal phase by evacuation;
- inhomogeneity of the parameters of the supplied steam or its discrepancy (fluid, dry, overheated);
- improper configuration or loading volume;
- an error in setting the parameters of the sterilization mode or their failure
Emulating indicators
Emulating indicators simulate the response of a biological indicator, which is the most stringent method for determining sterilization effectiveness. They mimic the behavior of spores, which are the most resistant form of microorganisms, to provide a reliable indication of sterilization success. Emulating indicators are often used in conjunction with other indicators to ensure a comprehensive monitoring system.
Requirements for emulating (Type 6) indicators. Emulating indicators designed for all critical process variables for the process given in table 2
Table 2.
| # | For the different sterilization processes, the following critical process variables are defined as being critical | |
|---|---|---|
| 1 | Steam 6, steam indicator | Time, temperature, moisture |
| 2 | Dry Heat | Time and temperature |
| 3 | Ethylene Oxide | Time, temperature, relative humidity and ethylene oxide (EO) concentration |
| 4 | Radiation | Total absorbed dose |
| 5 | LTSF sterilization | Time, temperature, moisture and formaldehyde concentration |
| 6 | Vaporized Hydrogen Peroxide | Time, temperature, hydrogen peroxide concentration |
and reach an end point indicating exposure to a sterilization process at defined critical process variables within the relevant tolerances given in Table 3. Emulating indicators tested at the SV (test point 1) reach the end point (pass condition). Emulating indicators tested at the SV minus the combined tolerances (test point 2) not reach the end point (fail condition). Emulating indicators for steam exposed to dry heat at 140 °C ± 2 °C for 30 min ± 1 min not reach the end point.
Table 3 — Test and validation requirements for Type 6 indicators
| # | Sterilization process | Test point | Test time, min | Test temperature | Gas concentration, mg/l | RH, % |
|---|---|---|---|---|---|---|
| 1 | Steam class 6 | 1 | SV | SV | ||
| 2 | −6% | −1 °C | ||||
| 2 | Dry heat | 1 | SV | SV | ||
| 2 | −20% | −1 °C | ||||
| 3 | Ethylene oxide | 1 | SV | SV | SV | >30 |
| 2 | −10% | −2 °C | −15% | >30 | ||
|
Test point 1: The indicator, when validation testing at the SV, reach its end point (pass condition). Test point 2: The indicator, when tested at all SVs minus the combined tolerances, not reach its end point (fail condition). |
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Benefits of using class 6 indicators for sterilization
Using class 6 indicators for sterilization offers several benefits:
Quality assurance: Class 6 indicators provide a high level of assurance that the sterilization process has been effective, giving peace of mind to healthcare professionals and ensuring patient safety.
Compliance with regulations: Class 6 indicators are designed to meet strict industry standards and regulatory requirements, ensuring compliance with sterilization guidelines.
Process control and optimization: By monitoring sterilization processes with class 6 indicators, healthcare facilities can identify any deviations or issues early on, allowing for timely adjustments and optimization of the sterilization process.
Drawbacks of Class 6 Indicators:
While Class 6 indicators offer a high level of assurance in sterilization processes, they're not without limitations:
- Cost: Compared to other indicator types, Class 6 indicators tend to be more expensive.
- Interpretation: Accurate interpretation requires proper training and understanding of the specific indicator's characteristics. Misinterpretation can lead to false positives or negatives.
- False positives: Certain factors like air pockets or improper placement can trigger a color change despite inadequate sterilization.
- Not a standalone solution: Class 6 indicators shouldn't be used in isolation. They work best in conjunction with other monitoring methods like biological indicators for comprehensive validation.
- Limited information: They don't provide specific details about the sterilization process (e.g., temperature fluctuations).
Alternatives to Class 6 Indicators:
- Class 1-5 indicators: These offer varying levels of information and assurance at different price points. Choose based on your specific needs and budget.
- Biological indicators: Considered the gold standard, they directly confirm the absence of viable microorganisms but require longer incubation times and expertise to interpret.
- Physical monitoring systems: These systems continuously monitor critical parameters like temperature and pressure, providing detailed data for process optimization.
Best practices for using class 6 indicators
To maximize the effectiveness of class 6 indicators and ensure accurate monitoring of sterilization processes, it is essential to follow best practices:
Proper placement: Class 6 indicators should be placed in the most challenging areas of the sterilization load, such as the center of instrument packs or in the presence of materials that may impede the sterilization process. Should be placed at the coldest point of the autoclave as determined by the sterilizer manufacturers.
Regular monitoring: It is crucial to monitor the performance of class 6 indicators regularly to ensure their reliability. This can be done through routine testing and periodic validation of the sterilization process.
Proper interpretation: Class 6 indicators should be interpreted according to the manufacturer's instructions. Visible color change in the indicator should be considered a pass, indicating that the sterilization process has been effective.
Common misconceptions about class 6 indicators
Despite their importance in sterilization processes, there are some common misconceptions about class 6 indicators. It is essential to address these misconceptions to ensure a clear understanding of their role and effectiveness:
Misconception: Class 6 indicators are foolproof: While class 6 indicators provide a high level of assurance, they should be used in conjunction with other monitoring methods, such as biological indicators, for comprehensive sterilization validation.
Misconception: All class 6 indicators are the same: Class 6 indicators can vary in terms of design, performance, and compatibility with different sterilization methods. It is crucial to select the appropriate indicator for your specific sterilization process.
Conclusion
Class 6 indicators play a vital role in ensuring the safety and sterility of various industries, particularly in healthcare and pharmaceuticals. By monitoring sterilization processes, steam sterilization cycles and providing a visual confirmation of their effectiveness, class 6 indicators offer a high level of assurance and compliance with industry standards. By following best practices and selecting the right class 6 indicator for your sterilization process, you can maintain the highest level of safety and sterility in your operations.
FAQ
Chemical indicators provide visual confirmation that the sterilization process has reached the required conditions for effective sterilization, ensuring quality assurance.
The types of chemical indicators include exposure indicators, special indicators for specific tests, internal indicators for assessing critical process variables, and emulating indicators that simulate biological indicators.
Class 6 indicators are the most stringent and reliable indicators for steam sterilization. They monitor steam sterilization processes and provide a high level of assurance that the sterilization process has been effective.
