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High-Level Disinfectants (HLDs) are used in healthcare to kill microorganisms on medical devices such as endoscopes, ultrasonic probes, and cardiac catheters, in order to prevent the transmission of infectious diseases.  HLDs are often formulated with aldehydes, peroxides, and peracetic acid.  All HLDs are heavily regulated by FDA.

The photo below shows a gastroscope soaking in high-level disinfectant to kill bacteria, viruses, fungi, and most spore-forming microorganisms.

FDA has set clear guidelines for testing, which include the following:

Of these tests, companies often find the Tuberculocidal Rate-of-Kill and AOAC Sporicidal Activity Tests to be the most challenging. The Tuberculocidal Rate-of-Kill uses Mycobacterium terrae, a surrogate of Mycobacterium tuberculosis.  Mycobacteria have a waxy coat that is hard for HLD products to penetrate.  The time and temperature in which an HLD product can achieve 6-log kill in the Tuberculocidal Rate-of-Kill test determines the high level disinfection time.

Per FDA regulations, HLDs must also qualify as sterilants by passing the AOAC Sporicidal Test. The AOAC Sporicidal Test uses bacterial endospores which have a tough, calciferous coating and are inherently more difficult to kill than actively-growing bacteria.  For the AOAC Sporicidal Test, Bacillus subtilis and Clostridium sporogenes spores are dried onto porous porcelain penicylinders and silk suture loops, where they find plenty of places to hide. All of these factors make the AOAC Sporicidal Test quite challenging.

The market for HLD products is driven primarily by the demand for fast, easy to use, and affordable high-level disinfectants.  If your company is interested in bringing an HLD product to market, please contact Microchem today.