When the first natural food store opened in my town nearly 3 decades ago, there was a shampoo in a white bottle with green silk screened print. It started with an "A", although I can't remember exactly what the name of it was.
It smelled wonderful, but the cost was astronomical and it left a grease slick in my hair. I inquired about it with one of the sales people, who handed me a book....written by the maker of this product, in order to promote it.

The entire book was about the dangers of Sodium Lauryl Sulphate, including unproven accusations and assumptions that he pushed in order to push his "good smelling", useless, expensive product, that did NOT contain any SLS.
Since this ingredient was in so many products, and so many gullible customers were led to believe it was dangerous, the manufacturers had additional studies and tests done in 2004, that proved, once and for all, that SLS is non-carcinogenic.
What they did find, is an older detergent called Ethenolomine Lauryl Sulphate that was contaminated with nitrosamines in some shampoos that also contained SLS.

The book also pointed out that SLS is used as a water softener and foaming agent for stronger cleaners. To say that it's dangerous because it's used in fire-fighting, is like saying that glycerin is poison just because it's an ingredient used in anti-freeze. The MDS sheet on this product warns that it is an eye-irritant.....of course, any thing strong enough to clean your hair and scalp will probably irritate the eyes.

If you do some research, you will find that this coconut-based ingredient has been the subject of misinformation, rumors, and deliberate untruths, for the sake of profits.
I help take care of Four women in their nineties, who have all used commercial shampoos for decades, and every one of them had enough common sense to close their eyes as the shampoo began to drip down their foreheads.
The best way to stop an unjust rumor, is to research the truth about it and be committed to no longer repeating and perpetuating it.