On 2017-12-13, Martin Brown wrote:

On 13/12/2017 14:38, harry wrote:
On Wednesday, 13 December 2017 14:00:07 UTC, Adam Funk wrote:
I got a package today with the "dead tree & fish" label on it & a
13-page safety data sheet inside. It turns out that desoldering braid
is so labelled because copper is "aquatic acute 1, H400" and "aquatic
chronic 1, H410". (The other component, rosin, is marked as "skin
sens. 1, H317".)

I'm a bit surprised that copper is apparently safe to contain & carry
drinking water but a hazard if dropped in water outside. What am I
missing here?

The surface area to weight ratio. Copper pipe isn't that easy to
dissolve whereas desolder braid will rot away quite quickly. It can be

Good point.

quite bad for fish. It is true for all heavy metals to a greater or
lesser extent even iron which we need for haemoglobin can be toxic.

https://en.wikipedia.org/wiki/Copper#Toxicity

I recall a copper tainted well not far from here which in times past
resulted in a lot of unexplained illness in the people who used it.
There were a fair number of copper mines round here in the distant past.
It isn't clear if arsenic colocated with the copper mineral vein wasn't
at least partially responsible for their problems.

Some copper mine spoil heaps have grass that has adapted to growing on
highly copper rich soils where there is almost no competition. Humans
can normally tolerate some copper in their diet but certain breeds of
sheep and dairy cows are prone to concentrating it and then expiring.

http://www.fwi.co.uk/livestock/farme...g-in-sheep.htm

(and links therein)

That all makes sense, thanks. The other thing I thought of after
posting the question is that "outside" water might be acidic or
otherwise more capable of dissolving copper than drinking water is.