Just like lead
There will be bans on unique chips that uses a minute quantity of mercury, safely bound up in a crystal lattice (like HgCdTe infrared diodes).
But power stations dumping tons of the stuff into the air or 3rd world plants putting it in the ocean will be exempt
Like when we had to redesign our product because a single vital timing chip wasn't available in ROHS. It probably didn't even have any lead in it but was made before ROHS and the maker wouldn't pay to certify it.
Of course the 2kg lead-acid battery that powered it was fine!