I'm in complete agreement with this. I would hesitate to work with it in a lab even. I've worked with my share of toxic chemicals and meds (IV Chemo). Too much can go wrong.I've always been surprised that one of the more toxic chemicals that reefers use, and one of the harder ones to use safely at home, is generally ignored as a safety risk.
If I were to use formaldehyde in a lab, the safety requirements would definitely involve using it only in a fume hood to avoid any exposure. But reefers use it to treat fish at home quite often.
I've never used it at home, and likely never will.
This article today is a reminder of the health risks:
Formaldehyde causes more cancer than any other toxic air pollutant. Little is being done to curb the risk