I'm sure you know to be very careful with the Cyanotype chemicals, right? A number of years ago I assisted for a Cyanotype class and got so, so sick from being in the darkroom with the chemicals, I couldn't go back. That never happened with any other photography process.
You're still the only person I've ever heard of who has the misfortune of getting ill from cyanotype chemicals
I don't see how unless you were fling around the ammonium citrate green so it'd kick up dust. Ammonium Ferric Citrate is actually used in foodstuffs, it's listed on a certain "iron" soda popular in Scotland. Pot.Ferri is even less likely to kick up dust because it looks like red table salt. Once it's all into solution there's no smells or fumes. Sunprint paper for kids is just cyanotype-soaked & dried paper...
You weren't mixing the solution with a strong (like HCL - not straight vinegar) acid, right? And there wasn't the smell of almonds anywhere ... ?(! that's cyanide gas smell by the way)
I could see your point if it was the 1 solution, more complex cyanotype(II) formula that Dr. Mike Ware came up with. That is suppose to be a bit more toxic. I mostly disagree on Dr. Ware's "disadvantages" points of the traditional formula so I just stick with the traditional formula. His formula seems to involve heating at some stage too...