http://www.epoxyproducts.com/nsp120.html great product, primitive website.

A low amine emissions epoxy adduct that is approved by NSF/FDA for 'large' water systems. Coating the internals of a 'small' tank will probably exceed the leachable emissions limits (total wetted surface area to volume ratio). I use a carbon packed filter downstream of the tankage in an attempt to 'strip' out the excess amines, etc.
Available in quart (2) containers. Easily 'rolled-on' to clean/'bright' tank internals.

hope this helps