Q: Why is it said that SLS and many other man-made chemical surfactants found in conventional shampoos are neither ideal or safe for use in personal care products ?

A: Yes, you heard this correctly. According to the Cosmetic Ingredients Review (CIR), what you heard is exactly this. Read it for yourself here:

By the way, Sodium Lauryl Sulfate is the stuff used in car washes, garage floor cleaners, engine degreasers - and in about 90% of products that foam.

http://www.cir-safety.org/staff_files/alerts.pdf

it says: "Sodium Lauryl Sulfate and Ammonium Lauryl Sulfate are irritants in patch testing at concentrations of 2 percent and greater, and that irritation increases with ingredient concentration. In some cosmetic formulations, however, that irritant property is attenuated. The longer these ingredients stay in contact with the skin, the greater the likelihood of irritation, which may or may not be evident to the user.

Although Sodium Lauryl Sulfate is not carcinogenic in experimental animals, it has been shown that it causes severe epidermal changes to the area of the skin of mice to which it was applied. This study indicates a need for tumor-enhancing activity assays.

Autoradiographic studies of rat skin treated with radiolabelled Sodium Lauryl Sulfate found heavy deposition of the detergent on the skin surface and in the hair follicles; damage to the hair follicle could result from such deposition. Further, it has been reported that 1 percent and 5 percent Sodium Lauryl Sulfate produced significant number of comedones when applied to the pinna of albino rabbits. These two problems - possible hair loss and comedone formation - along with proven irritancy, should be considered in the formulation of cosmetic products".

Make your own conclusion. Consider that a conventional daily shampoo contains 15% to 20% SLS. Our dish-washing detergent contains 30% to 40% SLS.