Date:         Mon, 30 Dec 2002 12:45:13 +0000
Reply-To:     Anthony Polson <acpolson@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Anthony Polson <acpolson@HOTMAIL.COM>
Subject:      A WARNING!!! (Was: Cleaning the water tank!?)
Content-Type: text/plain; format=flowed

Hi Dave,

I am not speaking from a basis of any specialist knowledge, but I am
dismayed to see several people, including yourself, recommending
Chlorine-based bleach as though it were intrinsically safe.

In fact Chlorine-based bleach generates some of the world's most dangerous
chemicals, both in its manufacture and use.  These chemicals are called
Dioxins, and they pose a massive threat to human health and to the global
ecosystem as a whole.  There are strong links between Dioxins and cancer and
birth defects.  At Seveso, Italy, they were the cause of one of Europe's
most massive ever public health disasters.

Throughout Europe, the unequivocal advice is that Chlorine-based bleach
should be used sparingly if at all.  Even when disinfecting the drains, it
is strongly recommended that only small quantities should be used and for a
maximum of 20 minutes, after which dioxin production begins to accelerate.

Surely there are serious implications to using any but the most sparing
quantity of bleach for the shortest possible time in a potable water tank.
It's no good saying that public water supplies include Chlorine-based
bleach, because their concentrations are orders of magnitude lower than we
would be likely to use.  Indeed, many drinking water suppliers are using
ultra-violet light to disinfect water, precisely because of the high risk to
public health that is posed by Dioxins.

It must be far safer to carry out hand cleaning of a potable water tank
using a detergent, followed by disinfecting with vinegar (thanks to Stan
Wilder for suggesting this).  Vinegar carries near-zero long term health
risks, which is why it is used in the food industry as a long term
preservative.

Another alternative is bleach that's based on Peroxide.  This is widely sold
in Europe as a more eco-friendly alternative to Chlorine-based bleach.  It
disinfects just as well as Chlorine-based bleach, but it produces virtually
no dioxins.

I realise that European and American approaches to the environment are very
different, and that advice on hazardous chemicals may be less easily
available on your (western) side of the pond.  However, the principles of
chemistry are the same, and no-one who knows about Dioxins would risk their
production in a potable water tank.  Of all places, surely this is one where
Chlorine-based bleach must be avoided.

I would forget the Chlorine-based bleach and go for a good scrub with
detergent followed by sterilisation with vinegar.  (Thanks Stan!)

Best regards,

Tony

('84 Vanagon in the UK)



------------ Original Message ---------------

Date:    Sun, 29 Dec 2002 18:04:40 -0500
From:    David Brodbeck <gull@CYBERSPACE.ORG>
Subject: Re: Cleaning the water tank!?

On Sun, 29 Dec 2002, Jason Weisberger wrote:

>Bleach seems to not be in keeping with "potable" - are you suggesting
not
>use the internal water tank for drinking/cooking water on camping
trips?

Well, some people don't, but I have.  Don't worry about the bleach -- as
long as you use chlorine bleach, it's the same basic chemical used in
city water systems.  Just rinse thoroughly to get rid of the chlorine
taste and smell, and you'll be fine.  If the tank is slimey or has
visible
growth inside, you should take out the plug on top and scrub it first,
since chlorine can't disinfect if there's dirt in the way.

Incidentally, when storing the van between trips I like to take out the
big plastic plug on top of the tank, lay a clean rag over the hole, then
snug the plug down on top of the rag. I figure this will allow enough
air
in to keep condensation from forming in the tank.  If it stays dry,
nasties can't grow in it. ;)

David M. Brodbeck (N8SRE)

---------------------------------------------



_________________________________________________________________
The new MSN 8: smart spam protection and 3 months FREE*.
http://join.msn.com/?page=features/junkmail&xAPID=42&PS=47575&PI=7324&DI=7474&SU=
http://www.hotmail.msn.com/cgi-bin/getmsg&HL=1216hotmailtaglines_smartspamprotection_3mf