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Cleaning of Cosmetic Creams and Lotions from Laboratory Glassware

The cleaning of cosmetic creams and lotions from glassware is achieved through a combination of detergents, hot water – programmed in automated washing system.

by Miele


Cosmetic creams and lotions are typically thick nonwater soluble emulsions that adhere to the surface of glassware. While pre-rinsing with hot water is helpful prior to hand washing; removal of the thin film that often remains can still pose a problem. To overcome this, technicians often use a very strong alkaline detergent – but in most cases – this just compounds the problem, leaving a hard “skin” that is even more difficult to clean. To get the best results: A mild detergent in combination with an emulsifier should be used along with as much water as possible passing over the glassware surface. This is most effectively done in a laboratory glassware washer – specifically, The PG 8536

Effective cleaning is based on a balanced interaction of four important factors and these are:


In general, hotter water provides better cleaning and rinsing. The Miele PG 8536 glassware washer can heat wash and Dl water up to 95°C. additionally; wash and Dl water temperatures are independently adjustable on Miele systems for maximum flexibility dependent upon the cleaning application. For cleaning of cosmetic creams and lotions a wash temperature of 95° C is normally recommended.

Mechanical Action:

It is often assumed that high pressure must be used to provide good cleaning results. The problem is higher pressure means a greater likelihood of breaking delicate glassware. Miele’s high turnover rate (circulation) of water at a low discharge pressure provides the best results without risk of glassware breakage. How often the water and detergent contact the surface to be cleaned is actually more important than how hard it hits. Using only 2.5 gallons of water per cycle, the Miele PG 8536 glassware washer circulates at a rate of 156 gallons per minute. This compares with 25 gpm for typical household dishwashers and 60 gpm for typical lab washers. Miele’s high circulation rate ensures analytically clean results, reduces the wash time required, aids in energy efficiency and allows for lower detergent usage.

Additionally, the lower spray arm features special spray nozzles which angle and feather the jet spray for maximum coverage and impingement. It is also equipped with spray arm sensors which alert user if there is blockage.


Increasing the time of a wash cycle will improve the cleaning results. Unfortunately most labs can’t afford the time waiting for a washer to complete long cycles – that’s why fast cycle times are important. Miele systems utilize only 2.5 gallons of water per cycle which is heated by 6000 watts of power at 220 V. This means that less time is wasted waiting for the water to be heated up to temperature. And the PG 8536 high circulation rate speeds up the cleaning.

For cleaning of cosmetic creams and lotions a longer wash cycle may be necessary. The Miele PG 8536 features programmable wash times for flexibility in designing a customized cleaning protocol.


Selecting the proper detergent is an important step in achieving critically clean glassware. In this application stronger detergents may actually hinder the cleaning process. For cosmetic creams and lotions a mild alkaline powder detergent, neodisher® MA is recommended in combination with an acid neutralizer, neodisher® Z. This combination prevents the formation of hard-toclean surface skin, ensuring analytically clean results.

The Miele Solution

The effective cleaning cycle for this application is found in the PG 8536 Laboratory Glassware Washer. In combination with wash protocols designed by Miele specifically for cosmetic applications, the PG 8536 provides repeatable analytically clean results.

Direct Injection Baskets

If you are cleaning narrow-necked items such as volumetric or Erlenmeyer flasks, direct injection baskets provide remarkably clean results for hard-to-reach interiors. These direct injector baskets utilize a unique radical design where water reaches the end of each injector with equal pressure. This assures that all items are cleaned with the same outstanding results. Some manufactures use a grid type injector design, where water pressure may be inadequate on injectors which are farthest from the feed tube. Furthermore, these injector tubes are available in a variety of diameters and lengths for various glassware sizes – and can be easily arranged for custom basket configuration.


In summary, the Miele PG 8536 Laboratory Glassware Washer equipped with the proper wash protocol, baskets and detergents provides thorough cleaning of cosmetic creams and lotions from laboratory glassware.

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