MSDS are written by manufacturers who need to shield themselves from product liability lawsuits if someone buys their chemical, then does something dumb, gets his hand blown off and personal injury lawyers try to figure out whom to shake down for their 40% cut from the settlement. MSDS is supposed to be informative but there is no reason for the manufacturer not to exaggerate the risk warnings. Also it is a formulaic, tedious work according to government rules, to write MSDS documents, not really something a lab chemist would like to do for living, so MSDS is often written by office drones with little practical experience.

Speaking of beach: I kid you not, a bottle of pure river sand (used for column chromatography) supplied by Baxter for many years had the following warning on the label, in capital letters: "THIS PRODUCT IS KNOWN TO STATE CALIFORNIA TO CAUSE CANCER"

You see, sand = silicon dioxide => silicosis => lung cancer