text: is sodium lauroy, an ingredient found in toothpaste and shampoo, harmful? l? does sodium lauroyl cause cancer? no. it's a myth.  this is another myth/hoax/urban legend. the american cancer society has this to say about 'sodium lauroy' (sodium laureth sulfate):  "shampoo    rumor:  one chain email floating through cyberspace says a common ingredient in many health and beauty aids is known to cause cancer. the warning reads: “check the ingredients listed on your shampoo bottle, and see if they have this substance by the name of sodium laureth sulfate, or simply sls. this substance is found in most shampoos, and the manufacturers use it because it produces a lot of foam and it is cheap. but the fact is that sls is used to scrub garage floors, and it is very strong. it is also proven that it can cause cancer in the long run. i went home and checked my shampoo (vidal sasoon), it doesn't contain it; however, others such as vo5, palmolive, paul mitchell, the new hemp shampoo, etc. contains this substance."   fact:  sodium lauryl sulfate (sls) and its chemical cousin sodium laureth sulfate (sles) are known irritants, not known carcinogens. sls and sles are powerful surfactants (wetting agents) and detergents. they have industrial uses because they are detergents that exert emulsifying action, thereby removing oil and soil. there is no way of knowing where this internet information comes from, but there are a variety of web sites offering health and beauty products that are sls-free. according to david emery and his urban legends website, "all these web sites are maintained by 'independent distributors' for various multi-level marketing companies hawking natural personal care products. as a matter of fact, the majority of urls returned in a standard web search on the keywords 'sodium laureth sulfate' all point to versions of the same propaganda."   http://www.cancer.org/docroot/med/content/med_6_1x_shampoo.asp?sitearea=med