Safe Soap Study

During the course of lecturing about greywater in a class on Sustainability at Oregon State University this past fall, the students asked about the type of soaps that are "safe" for greywater reuse. A good question. I checked Oasis Design, the global leader in greywater reuse. Art Ludwig briefly discusses the issue for laundry soap where he states "... sodium, chlorine and boron are the no-no's. Most do-it-yourself cleaners rely on baking soda or borax, which are truly disastrous for plants". And he wisely recommends learning more in his book.

I have not seen much in the way of research regarding other bathing products, though. This recently published open access article in Energy Procedia titled The Inherent Biodegradability Characteritics of Light Greywater for the Different Bathe Products by Chinese researchers He Weitaoa, Wang Yayia, Yang Jiana, Zhao Xub explores this issue on bath soaps and shampoos. The sources of their research are the mainstream products that frequently show up on TV advertisements.

Their results?

There was little difference in biodegradation between the bathe products...[and]...It revealed that all of the products met the requirements of environmentally friendly products.

Maybe it does not cost extra to save the environment after all.

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It isn't pollution that's harming the environment. It's the impurities in our air and water that are doing it.

~ Former Vice President of the United States Dan Quayle