Can I Use Automatic Dishwasher Detergent Powder in My Clothes Washer?

Hello,
I have searched online on whether you can use automatic dishwashing machine detergent in a laundry/clothes washer, and the results are all over the place. When I say automatic dishwashing machine detergent, I mean the powder sort and the generic store brand, not the pods, gel, or other types.

I know you can use hand dishwashing soap in your laundry/clothes washer with no problem, but I can’t find whether or not it’s safe to use automatic dishwashing powder in my clothes washer.

I would guess, if you did use the automatic dishwashing machine detergent for a laundry/clothes washer, you would use a somewhat limited amount–but I am not even sure about this. Some brands of automatic dishwashing machine detergents have bleach in them. I expect you would not add automatic dishwashing machine detergent to your clothes washer until the water level is full to avoid this bleach negatively affecting clothes colors.

Thank you.
Perplexed in Pinopolis

Dear Perplexed,

You have a great question, and I understand why it is so difficult to “do a quick Google search” for the answer. People use dishwasher detergent to mean both the liquid soap you use for handwashing dishes and the much more powerful caustic powders, gels, and pods used for automatic dishwashers.

We will head back to introductory chemistry class for the answer, and keeping things super simple, I will stick to two main factors for my response. First, I also know that you specifically mentioned generic dishwashing powders. I am using name brands in my examples as the data is much easier for me to find, and the generic versions will be very similar as they are often made by the same companies, with perhaps more filler.

First up is pH. Water is generally pretty neutral and around seven or maybe slightly acidic. The higher the number, the more basic or caustic a chemical is. The soap that you use to clean your hands is around 8.

I looked up Cascade because it’s a widely recognized dishwashing detergent brand that I regularly use. According to the material safety and data sheet (MSDS), the pH is 11.0. Now, compare that to Tide’s of 8.1 – 8.5 when diluted to 10% solution. So, Tide is much closer to the pH of what you use to wash your hands. (If you are curious, a material safety and data sheet tells you how to handle and store chemicals safely.)

Not too long ago, I made a very silly mistake. Our teenagers are not the best at remembering to scrape their plates thoroughly, and sometimes the float that allows the dishwasher to drain gets food particles stuck. I’ve learned the trick of dislodging those particles and resetting the dishwasher (This was after a $150 repair bill where he was in and out of our home in less than five minutes.) I was in a hurry and didn’t think to put gloves on. My hand was in that water for less than a minute, and I had the beginning of a chemical burn. So learn from Heather, and don’t be dumb. Use gloves if you have to stick your hand in your dishwasher’s wash water. That detergent isn’t playing around.

What else has a pH of 11?

Hmm, oh, that would be our good friend sodium hypochlorite or… chlorine bleach. What happens if you soak your clothing in a strong bleach solution? It either wears out very, very quickly or gets holes. (Depending on how thick the material was to start with).

And I just touched on my second reason to not use powdered dishwashing detergent in your clothes washer. Most, if not all, contain sodium hypochlorite. 👆🏻 The problem with this isn’t that it has bleach, but that you don’t know the proportions, so it is all guesswork.

I suppose, in an emergency, if you had no laundry detergent available. And if you did not care if your clothing bleached. And if you were very prudent with the amount of detergent you used. And if you dissolved the detergent before adding it to the wash water. You might be able to get your clothing clean. However, this is a whole lot of And If’s. So, unless you have stumbled onto a lifetime supply of automatic dishwashing detergent and somehow lack access to laundry detergent, let us go ahead and file it under “B” for bad idea.

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