In message , at 10:25:58 on Tue, 19 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.

I was referring to the mercury instrument (I thought that was bleeding
obvious)

The problem with mercury is that even if not "abused" (whatever that
means) it has a tendency to get split, and when it does the tiny
droplets run everywhere and are very difficult to clean up.
--
Roland Perry