Interesting advantage of C-41 kits with separate fixer + bleach: Easier disposal.

[dcy]

I was just watching YouTuber Shaka1277's review of a particular C-41 kit, and he said something that caught my attention (link):

Any fixer, once used, will have dissolved silver salts in it. That makes it a hazardous waste that has to be disposed of at your municipal waste disposal facility. You can get around this by using the steel wool method to de-silver the fixer. Iron salts replace the silver salts, and the silver turns into metallic silver, coating the steel wool. The de-silvered fixer is safe to pour down the drain and the solid steel wool with silver coating can be tossed in the regular trash.

This doesn't work if your C-41 kit uses blix: The purpose of the bleach is to take metallic silver and convert it back into ionic silver. So it won't let the silver stay on the steel wool.

I thought that was interesting.

 

[koraks]

Interesting, and also correct.
The bleach is a bit of an issue due to the ammonium bromide, which is apparently nasty.

Things a slightly different if you take the used chemistry away for disposal to a dedicated facility. There it depends on the nature of the disposal process if it's still beneficial to have separate bleach & fix.

It's also different for large-scale labs since desilvering and regeneration of blixes is perfectly feasible and indeed commonly practiced (for paper; no high volume film blixes are used AFAIK).