Laboratory Cleaning: Best Practices Using a Household Dishwasher

Q. Our lab just has a regular household dishwasher that we use to clean labware. I heard this is not ideal, but it’s what we have. We’re using Alcojet detergent, but the instructions say to turn it into a liquid by diluting 1:100. Can we pour the powder straight into the dishwater powder cup in the door? Anything else we should do to get the most out of our household dishwasher?

A. You can dose straight Alcojet® Low Foaming Powdered Detergent right into the cup in the door of the household dishwasher.  The cup is typically sized to dose something in the vicinity of 1:100 detergent or so when diluted with the wash water.  Alcojet detergent is a very robust detergent that will work well in a range of likely dilutions.  When in doubt, you can always use a little more and then optimize as needed down the line.

As you mentioned, it is not ideal to use a household washer for scientific cleaning. Here are some tips that can help it do the job to slightly more exacting standards. 

• Try to avoid letting things dry on to anything that is to be washed.
• Presoak lab glassware in a detergent like Liquinox® Critical Cleaning Detergent or Alconox® Powdered Precision Cleaner (10-20 g/L or 10-20 mL/L), completely submerged prior to final washing in the household washer.  If the only detergent you have is Alcojet, you can pre-soak in a 1-2% Alcojet solution (10-20 g/L) – this would be far better than not presoaking at all, but not quite as good as using Alconox or Liquinox detergent.
• Pay careful attention to how you load things in to the washer.  Try very hard to avoid any upturned cup configurations. It will not only leave that glassware piece dirty, but will spread dirty wash water all over the the other labware and inhibit proper rinsing. Place things to be washed in racks carefully angled to assure complete gravity draining of any dirty wash water on the parts.
• Avoid caking detergent by making sure the cup in the door is dry before adding detergent and always add detergent just before starting the washer.   

Taking these steps will help ensure that your lab glassware is clean and residue free, however, a laboratory grade commercial dishwasher is always the best option for critically clean lab glassware. For more about cleaning laboratory glassware effectively, please watch our new video: How to Clean Laboratory Glassware and review our Labware Washer Guide.

To request an Alconox, Inc. detergent for free, please complete the questionnaire at Get Sample. For more information about any one of our Alconox, Inc. detergents, consult the technical bulletin for each product. Or click here to access each of our detergent’s Safety Data Sheets.

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