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Validating Glassware Washer Results

Lab washers go through installation qualification, operational qualification, and performance qualification

Mike May, PhD

Mike May is a freelance writer and editor living in Texas.

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Validating Glassware Washer Results

Although many of my friends claim that I wash any dish like it’s laboratory glassware—and I have done more than my share of lab “dishes”—I have never validated this claim. In fact, I can remember working as a research assistant, cleaning glassware from radio-labeled assays, and not checking a single thing about the efficiency of my cleaning.

Today, lab washers go through installation qualification, operational qualification, and performance qualification. Washers used in pharmaceutical science must even go through specific validation steps determined by the U.S. Food and Drug Administration. “Also, a scientist buying a washer for a lab wants some sort of verification that it is working,” says Malcolm McLaughlin, vice president, product and business development at Alconox, Inc. (White Plains, NY), and coauthor of The Aqueous Cleaning Handbook (

Related Article: Product Focus: Laboratory Washers

Validating a cleaning process requires several steps. As Dennis Luisi, field service supervisor, professional products division, Miele USA (Princeton, NJ), explains, it is “a multifaceted undertaking with many different aspects that require the careful attention of those ultimately responsible for its successful completion.” One piece of the process, he says, requires “familiarity with the cleaning and monitoring capabilities of the glasswasher.”

For a specific application, scientists also need to, as Luisi explains, “establish thresholds for the continued presence of those contaminants post-cleaning.” In short, how clean is clean enough?

Detergent details

Getting rid of all residue on glassware also depends on the detergent. “The detergent doesn’t care what the surface is,” says McLaughlin. “It cares what the residue is.” He adds, “Nothing can clean everything.” So validating a washing process must ensure that the detergent takes care of the residue generated in specific applications and that the racks and loading pattern reliably deliver detergent to the substrates being cleaned. “In our product line,” McLaughlin explains, “most new products were developed because someone ran into something that an existing detergent couldn’t clean.”

For example, scientists using heavy-metal radioactive isotopes can’t rely on standard detergents. “They need heavy chelators,” McLaughlin says. I suspect that means my hand-washing of that radioactive glassware didn’t get the job done.

For most scientists, a standard process does the trick. “An alkaline clean and an acid rinse will cover you for the vast majority of what you run into,” McLaughlin explains, “and most lab washers come with that capability.” Add a final rinse with water, and you can be pretty confident that your washing process removes the residue from your lab’s glassware.

Keep it clean

Part of ensuring that glassware is clean depends on a lab putting a system in place. This, says Luisi, requires “establishing and maintaining appropriate monitoring and maintenance programs for continued verification of cleaning results.”

Experts, including Luisi and McLaughlin, and their companies also help scientists keep their glassware clean. As Luisi says, “Miele offers full support for the installation and operation qualification portions of the validation process.” He adds, “Our protocols are written by factory-trained engineers, and we offer execution of those protocols in the field with technicians who know the equipment better than anyone.”

Related Article: Lab Washers: Selecting the Right Options, or Being Able to Add them, Makes all the Difference

The cleaning process, however, goes beyond the lab. Ultimately, scientists—in both industrial and academic arenas—need equipment and detergents that consistently provide the desired level of cleaning, all while not doing any harm. The process must ensure safe and effective products as well as consistent outcomes over time and place. As McLaughlin and his coauthors wrote in The Aqueous Cleaning Handbook, “There are challenging opportunities for advancement.” Not surprisingly, my old-school, hand-washing ways do not stand up to today’s glassware-cleaning needs.

For additional resources on lab glassware washers, including useful articles and a list of manufacturers, visit