On 6/12/2016 7:52 PM, Tim Watts wrote:
On 12/06/16 15:18, Brian-Gaff wrote:
Several messages both on Usenet and from people I know seem to suggest
that
most recycling or waste sites run by councils won't take plasterboard,
saying its a hazard. Excuse me, but my ceilings are made of the stuff,
if it
was in any way dangerous, we surely should have figured this out by now!
Maybe its just hazardous to the machinery that crunches everything up....
Brian


The principle reason is (apparently) it reacts with certain food wastes
to produce hydrogen sulphide (aka stink bombs) - however, the gas is
toxic in sufficient concentrations.

Don't dispute that H2S might be the argument, but I'm not sure of the
logic. Yes, it's toxic and the problem, indoors, is that you smell it
very easily at a safe concentration but then the nose gets saturated (or
something), and you don't smell it any more, and you die. But certainly
until the 1960's every decent school chemistry lab had a Kipps Apparatus
(and had done for 100 years) and I don't recall hearing of any fatalities.

H2S used to be used in the manufacture of heavy water. I have heard it
argued that one reason for the general UK reluctance for Candu and
similar heavy water reactors is that you couldn't site a heavy water
manufacturing plant in the UK because a significant accident there would
kill people 100 miles away. (Yes I know we had a heavy water reactor at
Winfrith, and had plans to build a commercial one, but we got the heavy
water for the prototype from Canada where they have plenty of space to
make it).

But there's sulphur in lots of things. If you stir up the black slime at
the bottom of ditches, or in drain gulleys, you get the distinctive
smell. It's been manufactured by anaerobic bacteria which of course
means they are operating the absence of oxygen. It oxidises fairly
readily in air. Waste tips only smell of it when they are disturbed.

Maybe there is some argument about ground water? But it's not very
soluble in water.