Two seconds of googling gave this as the first hit: Stainless 304 - Technical Data (http://www.assda.asn.au/304.html)
(http://www.assda.asn.au/304.html)
The alloy contains Chromium (20%), Manganese (2%) and Nickel (10%) in addition to iron, and what you have leached out is various salts of the above metals. How much problem you will experience because of this is impossible to say. Just make sure you distill your methamphetamine base (or at least recrystallize the HCl salt twice) to remove toxic heavy metals.