I cannot speak as to why this product would be so restricted. I have used it many times and it has never caused me or any of my fish any problems.
But with any chemical you should take proper precautions. Good ventilation during the application and curing process, I also recommend gloves. I like to use the surgical type disposable gloves.
It doesn't seem to have any stronger odour than GE1.
also the MSDS is lower on the page if anyone has sever concerns, just don't use it.