Used crib mattresses?

So I got a crazy good deal on a crib mattress at a consignment sale. The outside of it is almost plastic-y so I figured it would be pretty easy to sanitize. However, when I googled the best way to sanitize a crib mattress, I saw lots of comments about how a used mattress can increase the risk of SIDS. Does anybody know if there is any actual evidence of that, or is it just people being overly cautious? This is what the label of the mattress says and it seems to be in great condition.