SLS is a very widely used surfactant & degreaser, a chemical that is used in a wide variety of products including toothpaste, bubble bath, shampoo, soaps and much more to cleanse and (super) foam. Examine some of the labels in your bathroom and it's likely that you will find it.
Much is said about SLS and it's ability to irritate the skin. Chances are you've done some of your own research and perhaps come across those who prefer their toiletries to be SLS free. One possible reason for the conclusion that SLS is irritating to the skin is the fact that it's molecules are teeny tiny and have the ability to be absorbed.
In contrast, (SLSA)Sodium Laureth Sulphoacetate is a large molecule surfactant whose structure prevents it from being absorbed by the skin. This aspect is perhaps why it has found favour with those suspicious of SLS and its potential as an irritant, along with the fact that it is derived from Coconut and Palm Oils.
Both of these products work effectively. Both must be used by the home crafter with extreme caution - examine the MSDS of each and you will see exactly the same risk phrases; each in its dry form is an irritant to the airways and eyes and can cause serious damage. Always use with appropriate breathing equipment, protective clothing and in a well ventilated environment. It is worth noting that these dry powders become airborne the moment you open the bag. If you do so without breathing protection you will be coughing in an instant. This goes for the "noodle" form of SLS as well as the powder form.
Of course once your products are made and the ingredients combined and bound together such as in a bath bomb or bubble bar, they are quite safe.