Its BS, the chemical that these idiots were talking about is the fire retardant coating. It is toxic IF the board is on fire, within 10 seconds the fire should be self-extinguished. The smoke is toxic gas.
Some dumb ass confused this with the "smell" by from the warm exhaust fan. The smell is most likely from cooling oil residue from manufactured metal parts in the miner.
Their argument about high temp is laughable. They said its safe from normal computer because its not as hot as bitcoin miners. Dumbest shit i've heard. Pick an IR camera and look into your computer retards.
My source: Work in datacentre industry, EE degree.