It is very toxic (think cancerous ) you have to be careful with it. It is something to have another do unless you are doing a lot of it at a number of different times.
Just a little sniff of the dye can put you down quickly. This from a guy that stood in allot of very and vapors through my career.
There are other yellow dyes that I've run across but never played with them enough to see if they could be substitute, how much to use, soak time, .....
This stuff is really bad news.