Before a medical instrument can be sterilized, it has to be clean—truly clean. And achieving that level of cleanliness in a medical device reprocessing (MDR) environment depends entirely on the chemistry doing the work. The detergents used in this process are purpose-built, carefully formulated, and increasingly, enzyme-driven.
To better understand how these products work and why their design matters, three industry experts weighed in: John Howell, business development with Novonesis; Brandon Beyer, North American technical manager with Ingredients + Specialties from Univar Solutions; and John Harp, staff scientist and product management with Novonesis.
Two categories, one goal
Howell described the MDR detergent landscape as falling into two primary categories: enzymatic and non-enzymatic. Enzymatic detergents typically operate at a pH of 7 to 9 and combine surfactants with enzymes to remove soils from instrument surfaces. Non-enzymatic options divide further into neutral formulations—surfactant-based with no enzymes—and alkaline detergents, which pair surfactants with a high pH to break down clinical soils.
“They all kind of have a similar intent, but they go at it about different ways,” Howell said.
Beyer added a practical layer to that framework, noting that in MDR settings, the method of cleaning matters as much as the chemistry. Instruments cleaned in automated washer-disinfectors have different detergent requirements than those cleaned manually at a sink—and low foaming is critical in automated systems.
“Foam is not such a great thing when you’re doing medical device reprocessing and scrubbing,” Beyer said, “because you want to see that these devices are actually clean, and any foam obscures the vision.”
Design features that matter
Howell pointed to ASTM standard D8179 as a key reference for MDR detergent manufacturers. Among the critical design features the standard addresses: products must appear clear and uniform, disperse readily into water without gelling, rinse away completely without leaving residue, and produce minimal foam in automated systems.
“Time is everything in these reprocessing departments,” Howell said. “It’s got to go in, disperse, and immediately start the cleaning process.” At the end, he emphasized, performance is what matters most—the detergent has to clean what it claims to clean, whether that’s orthopedic instruments, colonoscopes, or other reusable devices.
Where enzymes come in
Harp explained that enzymes are strings of amino acids folded in a precise configuration that creates what is called an active site—the location where a targeted chemical reaction occurs. Critically, the enzyme itself is not consumed in that reaction, meaning a single enzyme molecule can continue working on soils repeatedly.
“In theory, one protease, if it did not denature, could go through and catalyze an unlimited number of protein cleaves,” Beyer said. “You get a lot of bang for your buck out of enzymes.”
Common MDR enzymes include proteases, which target proteins; amylases, which break down starches; and lipases, which address fats. Harp noted a newer technology gaining traction: nucleases, which go after extracellular DNA—a problematic soil type for reusable devices.
Beyond their cleaning power, enzymes offer practical advantages over alkaline alternatives. They require fewer handling precautions, work synergistically with surfactants, and are compatible with a range of cleaning methods—manual soaking, ultrasonic cleaning, or automated processing. They also minimize wear on delicate instruments.
“Enzymes are a good solution for greener practices,” Harp said. “They are becoming a standard in medical device processing.”
Follow the IFU
All three experts closed with a consistent theme: chemistry alone is not enough. Howell stressed the importance of following a detergent manufacturer’s instructions for use (IFU). Not all detergents are appropriate for all instruments—alkaline formulations, for instance, can damage endoscopes, which are expensive and delicate.
“Detergent manufacturers spend a lot of time on their IFUs,” Howell said. “It’s always important that you follow them and understand them.”
The standard articulated is simple but non-negotiable: There should be only one standard of clean—and that’s what all three are trying to achieve.
To learn more about Novonesis, click here.
Learn more about Ingredients + Specialties from Univar Solutions, click here.
Be sure to watch the first episode, Beyond the Scrub: How Enzymes Are Shaping the Future of Medical Device Cleaning and the second episode, Inside the Art of Cleaning—and What Happens When It Fails.
