The Laboratory Glassware Washer: The Unsung Hero of the Laboratory

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Please check out our Glassware Washer / Laboratory Glassware Washer section for more information or to find manufacturers that sell these products.

laboratory glassware washer is a piece of equipment that you usually don't think about until it malfunctions, and all work in the laboratory screeches to a halt. The lab glassware washer is a relative of the consumer dishwasher you might have in your kitchen, but it is manufactured at much higher standards of quality, precision, and durability. Laboratory glassware washers come in many sizes and shapes, from compact, undercabinet models to large, double-stacked units that can handle the glassware needs of half a dozen laboratories. Models developed in recent years often include programmable controls, and some are network-enabled, so that you can control them from your workstation.

Manufacturers also offer specialized laboratory dishwashers for applications in hospital labs and animal facilities, for example, and huge glassware washers for equipment used in pharmaceutical production. Most laboratories, however, will need a standard washer that can handle flasks, pipets, and other common items of glassware. These are available in a range of sizes, from compact, undercounter models to free-standing models that occupy an entire wall.

Undercounter Glassware Washer

An undercounter washer is generally the most basic, economical model of washer. This type of washer should have a strong pump for circulating clean water, multijet spray arms, direct spray injection for hollow items, and hot air drying. Also look for variable spray arm rotation speed and programmable controls so that you can customize cleaning programs for lightly to heavily contaminated glassware. A high heat cycle can be very helpful for removing tough substances like oil, agar, and wax.

For safety and efficiency, many undercounter models offer redundant temperature control and monitoring sensors, automated program cut-outs, efficient use of water and cleaning products, and racks that can be tightly packed for optimum use of space. A stainless steel chamber will hold up best under incidental exposure to laboratory chemicals. Internal components like pumps, seals, and other rubber and plastic bits should be designed so that they do not disintegrate with exposure to common chemicals and solvents.

The G7804 General-Purpose Laboratory Glassware Washer from Miele Professional Products (Princeton, NJ) is an entry-level undercounter model that can handle most of the basic cleaning challenges in a typical laboratory.

Free-Standing Glassware Washer

A large-chamber, free-standing washer can serve multiple laboratories or an entire facility. These washers are commonly used by institutions that have centralized glassware washing. Typically constructed of sturdy stainless steel, insulated for heat and noise absorption, free-standing washers may offer doors on both sides for access to racks.

A typical floor model will hold 100 or more flasks, and many have racks that can be customized for washing specialty items like pipets. These no-nonsense industrial systems will often allow you to control every variable of washing, not only water temperature and cycle time, but drying temperature, water pressure, water filtration, air circulation, steam condensation, and relative humidity.

The 1600 LXA Freestanding Glassware Washer Dryer from Lancer USA Inc. (Winter Springs, FL) can serve large, centralized facilities and accommodate bulky, nonstandard items.

Additional features

Whether you choose an undercounter or free-standing model of laboratory washer, your lab may require additional features like water softening, flowmeters, or heated deionized water rinse. Deionized (DI) water is better at solubilizing chemicals on the glassware because it is free of contaminating ions itself. The DI rinse also prevents introduction of new contamination by the rinse water.

Soft water provides better cleaning results than hard water, so an integrated water softener can improve the quality of cleaning. Softened water will also help with equipment maintenance by preventing scaling within the chamber and in spray arms, hoses, and fittings.

Lab glassware washers use specially formulated detergents that leave no residue on glassware. The wash is typically followed with a weakly acidic rinse. Some washers will automatically dispense metered quantities of detergent and rinse agent from large internal reservoirs, so that cups need not be filled each cycle. Some have vacuum drying to make sure the glassware is totally dry.

FlaskScrubber Dishwashers from Labconco Corporation (Kansas City, MO) have a vacuum drying system for thorough drying of glassware, particularly narrow-neck pieces like volumetric flasks.

A flowmeter allows the operator to monitor the amount of water the machine is using, and precisely control filling volume. A final rinse with heated deionized water can further improve cleaning results, removing residues and trace contaminants that could affect laboratory results.

When it is necessary to use different water supplies for different parts of the wash cycle, pay attention to the plumbing system of the washer. Deionized water should not be piped through the same system as tap water or recirculated water, and water used for rinsing should never contact waste residue from a previous cycle.

Airborne contamination may also be introduced through the air circulation system, so for sensitive applications, air filtration is necessary.


The umbrella of current Good Manufacturing Practices (cGMP) compliance covers every aspect of laboratory management, and glassware handling is no exception. cGMP-compliant laboratory washers must include the same high-end features as the standard models, plus enhanced features such as HEPA-filtered drying, secure controls, cycle documentation, fail-safe cycles, and program monitoring.

In laboratories where a fully cGMP compliant washer is not mandatory, a validated washer with external monitoring can provide good results.

Glassware Washer Networking

Your laboratory dishwasher may not be on Facebook (yet), but many new models of washers are provided equipped for connection to laboratory networks. Using an ethernet or RS232 connection, the humble glassware washer can become a part of the laboratory information management system (LIMS). Through the LIMS, the dishwasher can report data from a glassware washing cycle. The data then become a part of subsequent experiments carried out using that batch of glassware. If something goes wrong, the technician can look for and correct problems in the cleaning cycle.

A laboratory glassware washer is truly an unsung hero of the lab. Unlike more glamorous pieces of equipment that output publishable data, the washer quietly does its job day after day, producing glassware that many researchers take for granted will be sparkling clean and free of contaminants. However, improperly cleaned labware can ruin an experiment, often in such a way that no one ever knows what went wrong. Whenever an experiment succeeds, you can be assured your washer is on the job.

Additionally, the glassware washer, much like the home dishwasher, is a labor-saving device. Many working scientists still remember the days of hand-washing laboratory glassware. While hand-washing may provide a sense of control, it is labor intensive and the results are generally not as good as machine-cleaned glassware. Even when the washer is located outside the lab, in a central glass-washing facility, it is still an important member of the equipment “team” of a laboratory, and, like all other laboratory instruments, washer models are continuously improved and upgraded by manufacturers, offering improved performance and features.

Please check out our Glassware Washer / Laboratory Glassware Washer section for more information or to find manufacturers that sell these products.

Catherine Shaffer, M.Sc., studied Biological Chemistry at the University of Michigan.  Catherine reports full time for BioWorld Today, and her work has also appeared in Nature Biotechnology, Nature Medicine, and several other publications.