In message ,
"Christian McArdle" wrote:

This figure of 1 meter was IIRC calculated and reported in an IEE
newsletter, and repeated fairly recently.

It wasn't so clear. It said that anything above 1m was safe, but didn't
actually say that anything under 1m was not. They should, perhaps, have
worded it more carefully, although this may have required further testing to
determine a reasonable cut off point.

Also, there was nothing said about the effects of salts such as might be
found in cleaning and beauty products when going down the drain.


I hadn't considered waste - waste pipe is rarely (never?) "filled" with
water in the way that supply and heating pipe is, and the nature of the
flow is intermittent to say the least. On top of that, waste has been
90% plastic for many years now, and the only metal waste you are likely
to encounter is the odd cast-iron stack...

Contaminants in the supply water are another matter - treatments in the
heating water, salts in softened water and so on. Hmmm :-/

Hwyl!

M.

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Martin Angove: http://www.tridwr.demon.co.uk/
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