Читать книгу Antisepsis, Disinfection, and Sterilization - Gerald E. McDonnell - Страница 33

The concept of parametric control (or release) as a method to verify the effectiveness of a biocidal process is based on the understanding of all the key physical parameters that can affect its success or failure. Although theoretically this could be applied to any disinfection or sterilization process, it is generally restricted to well-characterized sterilization methods, including steam, dry heat, ethylene oxide, and ionizing radiation. An example is steam sterilization. The efficacy of steam is affected by the temperature and time, but also by the presence of air (see section 5.2). These parameters are reasonably well understood and can be physically measured (by using mechanical indicators [see section 1.4.2.3]) to ensure that the correct conditions have been met during a given steam sterilization cycle. In addition to monitoring these conditions, a series of in-process tests and controls are also conducted to provide further assurance that the sterilization process has been efficient. However, the concern with parametric release as an alternative to biological monitoring is in the control of other variables that can affect the effectiveness of the process. In the case of steam, these include the quality of the steam (see section 5.2), variations in the load being sterilized, and in the case of reusable devices, if the cleaning process has been sufficient prior to sterilization (see section 1.4.8). In most cases, disinfection and sterilization processes are routinely tested and monitored using a combination of biological and chemical indicators in parallel with mechanical indicators for parametric control.

TABLE 1.24 Examples of chemical-indicator standards

Referencea	Title	Summary
ISO 15882	Chemical Indicators—Guidance on the Selection, Use, and Interpretation of Results	Guidance for the selection, use, and interpretation of results of chemical indicators used in process definition, validation, and routine monitoring and control of sterilization processes
ISO 11140-1	Sterilization of Health Care Products—Chemical Indicators—Part 1: General Requirements	General requirements for production, labeling, test methods, and performance characteristics of chemical indicators to be used in the validation and routine monitoring of sterilization processes
ISO 11140-3	Sterilization of Health Care Products—Chemical Indicators—Part 3: Class 2 Indicators for Steam Penetration Test Sheets	Specific requirements for class 2 steam penetration test indicators
EN 867-1	Non-Biological Systems for Use in Sterilizers—Part 1: General Requirements	General requirements for indicators that are used to monitor the presence or attainment of one or more sterilization process variables
ANSI/AAMI ST60	Sterilization of Health Care Products—Chemical Indicators—Part 1: General Requirements	Requirements for chemical indicators intended for use with sterilization processes employing steam, ethylene oxide, irradiation, or dry heat

^aISO, International Standards Organization; EN, European Norm, from the CEN (European Committee for Standardization); ANSI/AAMI, American National Standards Institute/Association for the Advancement of Medical Instrumentation.