The specifications and safety data sheet are on this page, CASTLE MALTING®: Cleaning Products, but at first sight I only see the usual suspects, such as sodium carbonate and sodium carbonate peroxide. Maybe the enzymes are not part of the safety aspects?
Enzymes are named “-ase”. On the MSDS, I see “cellulase”, which according to its name, would appear to be something that helps to break down cell walls. I have not researched it further than that and can’t speak as to its effectiveness; however, this might lead you in the right direction. Hope this helps.
Ah, indeed, I stupidly mixed up cellulase and cellulose… Cellulase helps split up cellulose and related polysaccharides. But the product contains less than 1% of cellulase.
I used it years ago to clean all sorts of junk from all sorts of glass labware. It worked well but need a soak to give it time to work. Enzymes are awesome.
It also appears to contain phosphate sequestrants.
HDPE is pretty much impervious to everything. I don’t have a reason to believe that it would be dangerous to other plastics because it doesn’t seem all that dissimilar to other brewery detergents other than the cellulase.