Who knew dish soap could get so controversial? Lately, dish soap -- especially "green" dish soap -- has been all over the news. Here's why, and why you should care:

Turns out, that many self-described green cleaners contain 1,4-Dioxane [1], a probable human carcinogen created as a byproduct of petrochemicals used in a process to soften detergents. That finding became public in March, courtesy of Organic [1] Consumers Association, a consumer advocacy group that tested 100 “green” products to find that 47 had detectable levels of 1,4-dioxane. Of them, dishwashing liquids were the one of the most likely products to contain the probable carcinogen. In defense, many green companies said they haven't yet figured out a way to make effective dishwashing liquid that doesn't contain 1,4-dioxane -- but that they'll work on eliminating the stuff.

Since even green dishwashing liquids contain 1,4-dioxane, the one way to avoid the stuff is to make homemade liquid dish detergent [2], which Karina of the Tiny Choices blog gave a whirl. Concocting the substance from scratch isn't easy, however. Karina's planning to learn from her mistakes: "I think I’m going to have to try again, but next time, I’ll use a different kind of soap, a larger pot, and maybe mix in more water right at the beginning to thin it out."

Meanwhile, if -- like Katharine Wroth of Grist.org -- you're okay with the small amounts of 1,4-dioxane in green dish cleaners, read her test of six green dish soaps [3] to find out which one works best for you. The test has all the details on the cost, the eco-claims, and the cleaning capabilities of brands ranging from ecover to LifeTree. Read the article to find out which product wins out!

^{Photo by Beatrice Murch [4] via Flickr}