smf85 Loc: Freeport, IL

It would be great if Kodachrome would come back - that’s unlikely though. The film is silver halide based but the processing chemicals are toxic or extremely toxic, in particular the magenta fogging agent. I was able to get ahold of a chemical list for the process - one of the reagents was vanadium oxide. Vanadium can be almost as toxic as chromium (but at least it doesn’t have the hexavalent state). One of its principle uses is to catalyze sulphuric acid from sulphates. There are plenty of sulphates in the other chemistry of the process to catalyze. Might explain why the temperature was so important in the process. Lastly, the description of the chemistry involved with the fogging agent is consistent with vanadium/chromium chemistry.

However, all that being said it can create very strong dye colors that are quite stable, although not as stable as chromium compounds. Chromium pigments can last centuries (think artist pigments). They also tend to be opaque to IR light. I suspect that the original formulation contained chromium compounds as they were considerably easier to obtain prior to the 60’s. But I haven’t see anything that would confirm any of this, but if true it would put the chrome in the Kodachrome.