First, what is sodium lauryl ether sulfate? The term "lauryl" refers to a chain of twelve carbon atoms. This chain can be found in nature as part of fatty oils and fatty acids in plants and animals. Coconut oil is a good example of a vegetable oil containing the lauryl group.

Soaps have been made from coconut oil for centuries. The chemical name for these soaps is sodium laurate. Soaps don't work well in hard water, so chemists replaced the carbon-based acid in sodium laurate with a sulfur-based acid. The new substance is called sodium lauryl sulfate.

Both sodium laurate (indeed, all soaps) and sodium lauryl sulfate (SLS) are called anionic surfactants. Anionic surfactants are generally irritating.

A milder anionic surfactant can be formed by adding hydrophilic (water loving) groups to the SLS. This is done with a substance called ethylene oxide, which is made by "cracking" petroleum to form ethylene, then adding oxygen. The new surfactant is called sodium lauryl ether sulfate (SLES) or sodium laureth sulfate. SLES is much less irritating than either sodium laurate or SLS.

Neither sodium laurate, SLS, nor SLES is known to cause cancer, nor are they known to be teratogens or reproductive toxins. They are irritants, and the inflammation they may cause almost always clears in a few hours. This is also true of soaps.

Are SLS and SLES "perfect" chemicals? No. As mentioned SLS is irritating. SLES is irritating, too, but less so.

Are there other anionic surfactants that natural cleaning companies use? Sometimes these companies say, "No SLS" but they use ammonium lauryl sulfate (ALS) instead. Since the cation (ammonium, potassium, or sodium) has little effect on the toxicity or the irritancy this is a deception, not an alternative. Certainly SLS and SLES are superior to the conventional alternatives such as linear alkylbenzene sulfonate (LAS).

I hope this helps answer your question.