Nick, I have never heard of HAS (hydroxyl amine sulfate) going boom.

As for the patents, they must contain a working example of the formula, but it does not have to be the preferred formula. It must be within the spec though. And you can patent a formula or a process.

So, a patent may say that they use 1 - 5 g/l of NaBr or alkali metal such as this, or mixtures, and they may end up using 2.74 g/l of LiBr and 0.10 g/l of KI in the actual formula. That is a wild example, but you get the idea.

The same problem crops up in these published formulas. They are not exactly right and I have no idea what they do to your film or paper. I have seen variations that I did in halide content that caused huge swings in interimage or sharpness with the picture looking superficially correct.

I know that using CD4 with color paper can look right but lead to very bad dye stability and this is published.

PE