I wonder if that was the dye that harmed my Mum?
X-Ray fluorescing dye used by British NHS in 1950s and 60s, for spinal X rays, it was toxic but they denied it and covered it up. it caused scarring, arachnoyditis, that resulted in terrible pain, pinch nerves, as a result.
I vaguely recall it was something like "naphthalene orange" or some other such name, but heck it could have been "blue" for all I recall as the memory banks ain't what they used to be
quite a few of the dyes developed turned out to be toxic.
Steelworks, oddly enough, produced a lot of such materials, since they used "coke", not coal for firing the furnaces, so large steelworks have coke making plants on site, taking coal deliveries in vast quantities to make coke, and selling the by products of the conversion for good profit.
producing coke creates lots of very toxic but important organic chemicals, used for dyes, explosives etc.
likewise back when towns were lit by gas, the gas works produced such as well.
