Sterilization is an important technique employed to sterile medical devices, products as well as laboratory equipment. Despite the multiplicity in the methods used to make substances microbe-free, steam sterilization is most commonly utilized but merely exposing the products to steam at elevated temperature does not ensure the efficiency of the process. Rather, validation is required through some other means. As it happens, there are no direct methods to know whether a pack or a medical device has been sterilized or not. For this purpose, chemical indicators are used. An effective, as well as inexpensive method, is the use of Comply steam indicator strips.
COMPLY steam chemical indicator strips
Chemical indicators are the substances that are employed in sterilization to ensure the success of the procedure undergone. Their job is to indicate that the parameters set to be achieved by the process have been met. One of these chemical indicators is the Comply steam chemical indicator strips.
Comply steam chemical indicator strips
As the name suggests, they are perforated white comply steam indicator strips which act as process indicators by changing or retaining their color to indicate sterilization or environmental exposure. In the case of a completely intact product after sterilization, the strip remains white but if the product has been contaminated by the microbes or the particulate matter present in the air, the color of the strip turns brownish or black to signal the adulteration in the product.
Chemical indicator strips before and after color change
How do the steam indicator strips work?
The chemical indicator tapes are self-adhering steam indicator tapes that are put into each bag of the product that is to be sterilized as per the recommendations of the Centers for Disease Control and Prevention (CDC). On one side of these tapes, a chemical indicator is printed. Before the process of steam sterilization, these indicator tapes are used for sealing the packages. The indicator changes color after processing which is a clear sign that the package has been processed.
How to use steam indicator strips?
Chemical indicator strips are employed to ensure that the autoclave is working according to the specifications. During each trial, the autoclave is passed through multiple 15-minute cycles and time variations are calculated. Chemical indicator strips are then dipped into a 0.9% aqueous solution of NaCl followed by packing. Furthermore, the sterilization process is conducted at 121°C. After a specified time, the strips are analyzed for any color change.
Different types of chemical indicator strip
Uses of steam indicator strips
- Steam indicator strips are used in an autoclave during the steam sterilization process where these strips help to monitor all stages of the sterilization process. The purpose is to make sure that the autoclave is working properly and that all the necessary conditions required for sterilization are met.
- These are also vastly used in common steam sterilization processes for qualification as well as routine load monitoring and play a vital role in sterility assurance programs.
- These steam indicator strips are used in biological sterilization processes to ensure complete microbial inactivation.
- Chemical indicator strips are also used for exposure monitoring where these change color after sterilization which helps indicate the operator handling the items that the pack has been sterilized without opening the package.
Biological indicators for sterilization
Infection control protocol requires the medical instruments to be sterilized in order to prevent infections in the patients. Inadequate sterilization can cause exogenously acquired infections. Surgical site infections are one of the most common infections along with urinary tract infections and respiratory infections that are contracted during a hospital stay. To avoid these infections, medical instruments are sterilized mostly by steam sterilization. For this purpose, biological indicators are used.
During the steam sterilization processes, these sterilization indicators such as indicator tapes are used to enable routine monitoring, qualification, and load monitoring. To achieve a specific level of microbial inactivation, these indicators are used to ensure that the conditions during a steam autoclave cycle were adequate to achieve the specified level of microbial inactivation. Biological indicators are used in the pharmaceutical, medical devices, and biotechnology industries.
Chemical indicators for sterilization
Chemical indicators for sterilization are used to sterilize the instruments with the help of chemical vapors. It is a method that is a part of quality assurance. Cleaning the instruments using chemical sterilization can ensure the office staff and the patients that the instruments have been properly and carefully sterilized and will not cause the spread of any disease or infection. Commonly used chemical indicators include bromocresol green, methyl red, litmus, bromothymol blue, and phenolphthalein among others.
There are two types of chemical indicators for sterilization which are as follows:
- Internal chemical indicators
The internal chemical indicator strips find the collapses of sterilization or disinfection processes. They are utilized for the indication of sterilization failures within the minimum time possible.
- External chemical indicators
The external chemical indicator tapes ensure that the sterilization process was performed on the packs. They confirm that the packaging material has been previously exposed to sterilization processes.
Conclusion
Steam sterilization is one of the most employed methods in industries. Owing to its ease of operation as well as the absence of any special requirements for its processing, this method has gained superiority over sterilization procedures. However, the need for validation of the method as well as a time of sterilization still remains. The use of chemical indicator strips has been the method of choice to achieve the purpose. These strips are inexpensive and easy to use, making them ideal for use in all steam sterilizers. Moreover, interpreting the results is as uncomplicated as their use.
