This article is from the Food Preserving FAQ, by Eric Decker firstname.lastname@example.org with numerous contributions by others.
Mark Preston wrote:
1020 Chestnut Street
sells many chemicals for food. Usually in CP (chemically pure) which is
about 5 or 6 grades higher than food grade. This is for the home sausage
maker quantities of such stuffs.
For the commercial end see:
who sells to all large, larger or largest sausage and ham makers."