Well if your shampoo is pure SLS, then I'd see the relevance of the MSDS to the decision-making process. Since NONE of them are pure SLS...
This could be done with any substance. I know there must be a MSDS for oxygen, and one for Vinegar. BTW I noticed acetic acid listed as a questionable ingredient at that EWG website. Know what acetic acid is? VINEGAR, which I use instead of bleach 99% of the time.
Oxygen under the wrong circumstances and in too high a concentration can be dangerous. I don't see anyone suggesting we stop breathing.
Actually I don't care what any given family decides to do regarding the use of whatever products. And if your experience is such that you know that using something with SLS is a problem, then by all means, avoid it! I do the same when I see ingredients that I know are a problem for me--like lanolin, wonderful natural lanolin that will make me itch and take my skin right off...yet there it is in some of the high-end "hypo-allergenic" natural soaps..

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Big peeve of mine is seeing the label "hypo-allergenic" on substances that I know very well ARE allergens, like Seventh Generation's Latex pillows. Cut me a break!!! and how stupid do they think we are?
But please make the decision based on fact and personal experience rather than fear mongering or hyperbole.
That's all I suggest.
