In message , at 18:30:37 on Mon, 18 Jul
2016, tim... remarked:
It's every much the same sort of thing: banning a commodity because
it's harmful/unethical or whatever.

There is a mile of difference between unethical and harmful, especially
when in normal use the item isn't harmful at all, it's only harmful if
it's abused.

Ivory hunting is harmful to elephants.

The reason I mentioned that one example (rather than say a pesticide)
is that sufficiently old examples have grandfather rights. Which you
might be suggesting doesn't apply to mercury instruments??

The grandfather rights to antique mercury based instruments apply to
unrepaired ones (whether still working or otherwise).

as soon as they (the mechanism) is newly repaired they have to follow
the same rules as newly made, which means that their sale is banned.

Cite? If true, I agree; but I've never come across a situation that a
repaired grandfathered item is suddenly ungrandfathered.
--
Roland Perry