Sterility Assurance Level and Methods of Sterilization

A minimum of 160 °C for at least 2 hours.

They are used to monitor and record the temperature within the steriliser, ensuring that the specified temperature is achieved throughout the load.

Validation ensures that the chosen process delivers an adequate and reproducible level of lethality, leading to an Sterility Assurance Level (SAL) of 10-6 or less.

<p>Biological indicators are used to demonstrate the effectiveness of the sterilization process by testing the survival of specific microorganisms under the chosen sterilization conditions.</p> Signup and view all the answers

<p>Standard dry heat sterilization is validated using temperature mapping and biological indicator studies, while depyrogenation of glassware is validated using a 3 log10 reduction in heat-resistant endotoxin as criteria. Biological indicators are not required for depyrogenation.</p> Signup and view all the answers

<p>Monitoring temperature profiles ensures consistent and effective sterilization by identifying any deviations from the desired temperature throughout the cycle, especially in the coldest position of the chamber.</p> Signup and view all the answers

<p>Dry heat sterilization at temperatures greater than 220 °C is typically used for depyrogenation of glassware, which involves the removal of endotoxins.</p> Signup and view all the answers

<p>Forced air circulation ovens ensure uniform heat distribution throughout the load, leading to more efficient and consistent sterilization.</p> Signup and view all the answers

<p>Biological indicators are used primarily to verify the effectiveness of sterilization processes for finished products and related items that have direct contact with the final product.</p> Signup and view all the answers

<p>Biological indicators are used for process development and validation as well as for routine monitoring when specified in the general chapter.</p> Signup and view all the answers

<p>Reduced sterilisation processes deliberately use less potent sterilization conditions to ensure that a small proportion of microorganisms within the biological indicator survive. This allows for verification of the indicator's accuracy and the effectiveness of the sterilization process when run under standard conditions.</p> Signup and view all the answers

<p>Biological indicators are designed to test the efficacy of a sterilization process by containing a defined challenge of viable microorganisms, typically bacterial spores. The resistance of these spores to sterilization methods allows for a direct assessment of the process's effectiveness in killing microorganisms.</p> Signup and view all the answers

<p>Bacterial spores are often used because they are highly resistant forms of life, are easily standardized, and can be stored for long periods under appropriate conditions.</p> Signup and view all the answers

<p>Custom-made indicators are used when commercially available indicators are unsuitable for characterizing the sterilizing effect within the product or in a position difficult to penetrate by the sterilant.</p> Signup and view all the answers

<p>When a validated sterilization process is used, there should be no surviving viable microorganisms in the biological indicator.</p> Signup and view all the answers

<p>The excerpt primarily focuses on the use of biological indicators for finished products and related sterilization processes, leaving out the applications of biological indicators in validating other non-terminal sterilization units.</p> Signup and view all the answers

<p>Inoculated carriers consist of a defined population of bacterial spores, often placed in a protective envelope, and a suitable carrier material that resists the sterilization process. The choice of carrier and envelope should be compatible with the chosen sterilization method.</p> Signup and view all the answers

<p>The type of carrier material, and the envelope if used, can significantly impact the resistance of the bacterial spores to the chosen sterilization process. For example, filter paper in glassine envelopes are often used for steam and ethylene oxide sterilization, while metal discs in non-woven fiber envelopes are used for hydrogen peroxide vapor sterilization.</p> Signup and view all the answers

<p>After being exposed to the sterilization process, the inoculated carrier is handled aseptically and transferred to a suitable culture medium. It is then incubated for a set period of time at the appropriate temperature. If no growth occurs, the sterilization process is deemed effective.</p> Signup and view all the answers

<p>Spores of <em>Bacillus atrophaeus</em> (e.g., ATCC 9372, NCIMB 8058, NRRL B-4418, or CIP 77.18) are recommended for ethylene oxide sterilization due to their demonstrated suitability and consistent performance in this process.</p> Signup and view all the answers

<p>Geobacillus stearothermophilus</p> Signup and view all the answers

<p>The number of viable spores per carrier for a biological indicator used in ethylene oxide sterilization must be greater than or equal to 10^6.</p> Signup and view all the answers

<p>One type is a system containing an inoculated carrier and a nutrient medium separated by a barrier. The sterilant must penetrate the barrier to reach the inoculated carrier. This type is used for processes like moist heat sterilization, ensuring steam penetration. The second type consists of a container with a population of test micro-organisms in a nutrient medium. These indicators are useful for monitoring the sterilization of aqueous fluids and only test for exposure time and temperature.</p> Signup and view all the answers

<p>Biological indicators are essential for validating gas sterilization processes because they provide a direct measure of the effectiveness of the sterilization cycle in killing target microorganisms.</p> Signup and view all the answers

<p>Sporulation conditions, carrier material, primary packaging, and sterilization environment.</p> Signup and view all the answers

<p>The nutrient medium provides the necessary environment for the test micro-organisms to grow and multiply if they survive the sterilization process. It must be suitable for the specific micro-organisms used and not be adversely affected by the sterilization method.</p> Signup and view all the answers

<p>1 to 5 minutes.</p> Signup and view all the answers

<p>Gas sterilization processes are multifactorial, involving interactions between several factors including gas concentration, humidity, temperature, time, and surface characteristics. These factors influence the effectiveness of the sterilization process.</p> Signup and view all the answers

<p>The self-contained biological indicator is designed so that the sterilant must pass through a barrier, such as a filter or tortuous path, to reach the inoculated carrier. This ensures that the entire process is tested, not just the exposed surface.</p> Signup and view all the answers

<p>Common gas sterilization methods include ethylene oxide, hydrogen peroxide, and peracetic acid, or combinations of the latter.</p> Signup and view all the answers

<p>The high spore population may not be adequately inactivated by the relatively low F0 value in this range. A lower spore count or a different test microorganism may be more suitable.</p> Signup and view all the answers

<p>A pH indicator is incorporated into the medium to facilitate detection of growth by changing color in response to changes in pH levels caused by microbial metabolism. This makes it easier to visualize growth within the media and determine the effectiveness of the sterilization process.</p> Signup and view all the answers

<p>The self-contained indicator, where the micro-organisms are in direct contact with the nutrient medium, is more sensitive to exposure time and temperature because the entire process is conducted in a single, sealed container. This ensures uniform exposure to the sterilizing agent and allows for precise measurement of the impact on microbial viability.</p> Signup and view all the answers

<p>Evaluating the resistance of a test microorganism for a specific sterilization process ensures its suitability, as it provides information about the microorganism's ability to withstand sterilization conditions.</p> Signup and view all the answers

<p>The z-value represents the temperature change required to reduce the D-value by a factor of 10. This value is used in calculations to determine the equivalence of cycle effectiveness.</p> Signup and view all the answers

<p>Spores of <em>Bacillus atrophaeus</em> have been found to be suitable for use as biological indicators for dry heat sterilization processes in the temperature range between 160 °C and 180 °C due to their resistance to dry heat.</p> Signup and view all the answers

<p>FH is the equivalent time in minutes at a temperature of 160 °C delivered by the sterilization process to the product in its final container.</p> Signup and view all the answers

<p>The D-value represents the time required to reduce the population of a specific microorganism by 90% (one log10) at a certain temperature. This value is crucial for determining the effectiveness of sterilization processes.</p> Signup and view all the answers

<p>Dry heat has a lower heat transfer coefficient than steam. This means that dry heat takes longer to penetrate materials and kill microorganisms.</p> Signup and view all the answers

<p>Dry heat sterilizers generally have a less homogeneous temperature distribution compared to steam sterilizers. This means that there may be larger variations in temperature within the chamber.</p> Signup and view all the answers

<p>F0 represents the accumulated lethality of the sterilization process at 121 °C.</p> Signup and view all the answers

<p>N0 is the initial number of viable micro-organisms, while N is the final number of viable micro-organisms after sterilization.</p> Signup and view all the answers

<p>D-values indicate the time required at a specific temperature to reduce the microbial population by 90%.</p> Signup and view all the answers

<p>The minimum temperature for moist heat sterilization is 110 °C.</p> Signup and view all the answers

<p>The theoretical z-value represents the temperature increase needed to achieve a tenfold reduction in the D-value.</p> Signup and view all the answers

<p>Achieving a sterility assurance level of 10-6 ensures a very high level of assurance that no viable microorganisms remain.</p> Signup and view all the answers

<p>The reference temperature for dry heat sterilization is 160 °C.</p> Signup and view all the answers

<p>F-values quantify the lethal effect of sterilization processes on microorganisms over time.</p> Signup and view all the answers

Test systems containing viable microorganisms to verify sterilization effectiveness.

A method to eliminate all forms of microbial life from a product.

Micro-organisms capable of living and reproducing, often used in biological indicators.

Resistant forms of bacteria that can survive extreme conditions.

A consistent number of specific microorganisms used in biological indicators.

Conditions under which some microorganisms survive to validate sterilization effectiveness.

Special indicators created when standard ones aren't available to assess sterilization effect.

Confirmation that a sterilization process effectively eliminates microorganisms.

Defined population of bacterial spores on a carrier, often with a protective envelope.

The carrier type must match the chosen sterilisation process.

Careful procedures to prevent contamination after sterilisation.

Systems that include an inoculated carrier and nutrient medium to test sterilisation efficacy.

Sterilisation process using steam to ensure penetration of the agent.

Substance that supports the growth of microorganisms after sterilisation.

Substance added to nutrient media to detect microbial growth based on pH changes.

A method using high temperatures to sterilize equipment.

The process of achieving a specific temperature for sterilisation.

Devices that monitor temperature during sterilisation.

Standard minimum requirements for effective sterilisation.

Measured by the level of lethality achieved during the cycle.

Validation process to ensure accurate heat distribution.

Process to remove pyrogens from glassware using high heat.

Regular monitoring ensuring proper sterilisation cycles.

A widely accepted biological indicator for moist heat sterilisation.

The time required to kill spores at 121 °C, varying from 1.5 to 4.5 minutes.

Specific strains of Geobacillus stearothermophilus approved for testing.

Materials on which spores are placed for testing.

Using 103 or 104 spores for certain sterilisation processes.

Time required to inactivate spores at 160 °C, varying from 1 to 5 minutes.

Temperature change required to achieve a tenfold reduction in microbial population.

A measure used for moist heat sterilisation based on log reduction of microorganisms.

A measure used for dry heat sterilisation based on log reduction of microorganisms.

D-value at 121 °C, representing the time needed to reduce viable spores.

D-value at 160 °C, showing the time required to reduce viable spores.

Initial number of viable microorganisms before sterilisation.

Final number of viable microorganisms after sterilisation.

Temperature change needed to achieve a tenfold reduction in the D-value.

A measure indicating the probability that a microbial population is effectively killed.

A logarithmic measure that indicates the reduction of viable microorganisms.

In a sterilization process reduced by 10 °C, 1 in 30 biological indicators may survive.

A suitable test microorganism for dry heat sterilization between 160 °C and 180 °C.

A sterilization method using gases, such as ethylene oxide and hydrogen peroxide, requiring biological indicators.

Micro-organisms selected to validate sterilization processes with specific D-values.

The number of living spores used in carriers for sterilization, at least 1 million (10^6) per carrier.