Chemical Indicators 101: Applications for Use

Since the 1st steam sterilizer was made by Charles Chamberland in 1880, researchers been employed by on solutions to monitor sterilization procedures. It was not before past due 1940s and early 1950s that biological and chemical substance indicators were utilized routinely to monitor the process. At that time, it was stated that no single quality-assurance monitoring method assures that any item is usually sterile: rather, it assures that the conditions for sterilization to occur were met. That very statement remains valid in todays healthcare environment.

As sterilization processes have evolved and become more complex, so have the monitoring systems that we use. Sterility assurance programs may consist of the following tools that healthcare management can use:

Physical monitoring
Chemical indicators/integrators
Biological indicators
Sterilizer preventative maintenance
Load record keeping This article discusses chemical indicators/integrators (CIs).
Chemical indicators are defined by the Association for the Advancement of Medical Instrumentation (AAMI) as sterilization process monitoring devices designed to respond with a chemical or physical change to one or more of the physical conditions within the sterilizing chamber. CIs are often used to detect sterilizer malfunction/failures resulting from improper loading of the sterilizer, incorrect packaging, deficiencies of the sterilizing agent, or malfunction of the sterilizer itself.

Remember, the pass reading of a CI does not mean that the item or products in the sterilizer load are sterile; it implies that the parameters or parameter for sterilization that the CI was designed to measure have been met. The usage of CIs is one portion of a highly effective quality assurance plan. They should be found in conjunction with a biological indicator (spore check ), physical monitors, a sterilizer preventative maintenance plan, and accurate record keeping for every sterilization load.

Chemical Indicator Classifications

AAMI ST-60 defines five classes of CIs and the precise performance requirements for every.

Process Indicators (Class 1): The standard of chemical indicators, they are referred to as throughput indicators also. These CIs are designed for use with singular items to end up being sterilized. They are made to demonstrate that that has been subjected to a sterilization procedure and also to distinguish between prepared and non-processed items. Types of Class 1 indicators are tape and the indicators found on paper or plastic peel pouches.

Indicators for Use in specific Tests ( Class 2): Also known as specialty indicators, Class 2 indicators are designed for use in specific test procedures as defi ned by relevant sterilization standards. Examples of Class 2 indicators are the Bowie Dick and Dart products used in steam sterilizers. These indicators check for the existence of atmosphere in the steam sterilizing chamber. A positive check would mean that atmosphere, which inhibits the circumstances necessary for sterilization, provides either not really been removed through the routine or provides entered the chamber through leaks in the system. Maintenance must be performed on the steam sterilizer to prevent the existence of air flow in the chamber during a sterilization cycle.

Single-parameter Indicators (Class 3): These indicators react to one of the critical process parameters of sterilization and indicate exposure to a sterilization cycle at stated values of the chosen parameter. Critical parameters typically chosen for steam sterilization processes are time or heat.

Multi-parameter Indicators (Class 4): These indicators are more accurate by design than Class 3 indicators. They react to two or more crucial parameters of the sterilization process and indicate contact with the sterilization routine at expressed ideals of the selected parameters. Temperature and period are types of steam sterilization parameters, and concentration and period of ethylene oxide are selected for EO sterilization.

Integrating Indicators (Class 5): These indicators, referred to as integrators, are created to respond to all critical parameters more than a specified selection of sterilization cycles. Their functionality provides been correlated to the functionality of a biological indicator (BI) under its labeled circumstances for use. This class of indicator can be used in place of the BI in many applications, reducing the overall cost of sterile processing thereby.

Usage of Chemical Indicators
When considering which course of indicator to use, you need to think about your internal and external chemical substance monitoring needs for your various sterilization systems.

External indicators are accustomed to distinguish between prepared and unprocessed items simply. A Course 1 indicator in the kind of tape, an indicating label, or the indicator legend on a paper or plastic-type material peel pouch is suitable and should be positioned on each package that’s designed for sterilization. The exterior CI generally exhibits a straightforward visual color alter that shows the bundle has been subjected to physical circumstances present throughout a sterilization process.

Internal indicators have to be used within each package that’ll be sterilized. Based on the complexity of the pack and products within them, a Class 3, Class 4, or Class 5 CI can be used. All internal CIs should be positioned in a section of the package that is determined to be the least accessible to sterilant contact. This may not always be in the center of the package.

AAMI states a Course 5 indicator might provide as the foundation for the release of processed items, excluding implants.

Integrator challenge packs make use of a Class 5 chemical substance integrator in a appropriate problem pack to monitor sterilization loads. The task packs are positioned within the sterilization load, beyond your packs, in the sterilization chamber, and also have been correlated to the eliminate attained in the AAMI 16 towel BI test pack. The full total result of the chemical substance integrator enable you to release the load, excluding implantable devices.

Results of exterior indicators and chemical substance integrator challenge packs can be read at the end of the sterilization cycle when the package is retrieved from the sterilizer. However , internal indicators must be interpreted at the time of use. Therefore all healthcare staff should be trained on the proper interpretation of a positive and negative result and what to do if a negative result occurs.

Be an Informed Consumer
In order to be an educated consumer you must be familiar with the parameters you wish to monitor, which will help you select the type or class of indicator(s) to purchase. Healthcare management should inquire the indicator manufacturer for reliability data and for the security and efficiency characteristics of their items. Queries to ask include:

Will be the indicator results simple to interpret?

Is it possible to store the indicator outcomes for a time period?

What sterilization parameters shall the indicator detect?

Is it correlated biologically? If so, what accurately are the specifics (organism, D-value, population)?

Does a shelf end up being had by the indicator lifestyle and what are the mandatory storage conditions?

By asking these simple queries, you shall ensure the right choice of indicators to meet up your quality assurance needs.

John A. Kurowski, BS, RN, is a worldwide clinical education supervisor for STERIS Corporation. He provides education and schooling to STERIS workers and healthcare services in the certain specific areas of infection prevention, the proper usage of STERIS items, and correct cleaning, decontamination, and sterilization techniques and procedures. He has been a featured speaker for both the local and national Association of periOperative Space Nurses (AORN), the Association for Professionals in Illness Control and Epidemiology (APIC), and the Society for Gastroenterology Nurses and Associates (SGNA). He is an active member of these organizations.

Get to know more chemical indicator

Leave a Reply

Your email address will not be published. Required fields are marked *