Re: Alternatives to PVC piping and coated wire?

[C Neurath <cneurath@tds.net>]

>Date: Thu, 03 Sep 1998 00:43:20 -0400
>From: Mike Ewall <catalyst@envirolink.org>
>To: dioxin-l@essential.org
>Subject: Alternatives to PVC piping and coated wire?
>
>I'm working on fixing up a home which has inadequate electrical wiring.
>Does anyone know if there are sources of electrical wiring and outdoor
>electrical conduit which don't have PVC, but which still meet the National
>Electric Code?  I need something that would be National Fire Protection
>Association (NFPA)-approved.
>
>Mike Ewall


Mike,

I've just finished wiring an addition to my own home and one of my prime
goals was to minimize PVC use.  It was actually quite easy.  "Alternative"
materials were more expensive but are probably higher quality and labor was
perhaps less than for PVC.

The wiring methods I used are actually standard for any
non-single-family-home electrical service.  I totally avoided PVC jacketed
NM and UF cable and substituted MC flexible galvanized steel jacketed
cable.  The wires inside the jacket are PVC insulated, but I would say the
amount of PVC in the individual wire insulation is only about 1/4 the
amount used in the PVC jacket.  Trying to find non-PVC insulation would be
difficult.  There is cross-linked polyethylene XP and more exotic
insulations like teflon or silicone, but I doubt any of these would be
easily obtained, especially inside an MC metal jacket.  You can also get
the flexible metal jacket ("Greenfield") without any wires in it, and pull
your own wires through it, so that would be the way to go if you absolutely
wanted to eliminate PVC.  I've used XP insulated wires in other situations
and it seems like a very tough insulation, and is probably rated as high as
most PVC in terms of heat resistance and water resistance.  I don't know
what types of additives XP contains.

The metal jacketed cable will fish through walls as easily as NM and
because of the metal armor, it can be used in areas more subject to abuse.
If you do decide to use it, I would recommend buying a special cutter for
about $30 which will make your job a lot faster and easier than trying to
cut it with a hack saw.

For straight runs, or for neater exposed wiring, thin wall galvanized steel
conduit, EMT, is cheap and easy to use and when used with the compression
style fittings is considered rain-tight so it can be used in exposed
locations.  It only costs a little more than equivalent PVC rigid conduit.

If you need flexible conduit that is suitable for outdoor use then you
might have a problem finding materials that don't use a lot of PVC.
"Liquidtight" flexible conduit is either all PVC or a flexible metal
covered with PVC as far as I can tell.  It's a little harder to design a
system that uses only EMT for outdoor use, but it can usually be done.  You
might need to get an EMT bender.  The only situation where you absolutely
need a flexible conduit that I can think of is if you have something that
vibrates a lot or needs to move, yet remain electrically connected.  Most
normal wiring doesn't have these problems.  Electricians often seem to use
the liquidtight stuff because it is very easy to use, not because it is
cheap or better than rigid conduit.

With the flexible metal jacketted cable or EMT conduit all boxes will also
be galvanized steel (or aluminum for outdoor use), so you automatically
eliminate the use of PVC boxes.

As far as meeting NEC, I am not a licensed electrician but I have
researched the NEC and I have talked to licensed electricians and all the
above materials can not only meet code, but they are generally considered
to meet the more stringent code requirements for commercial or multi-family
buildings.  Talk to any electrician and they can set you straight on all
this stuff as they use it every day.

Oh, and this topic reminds me of a point that was made at one of the
Citizens Dioxin Conferences by a representative from the plumber's union:
They didn't like working with PVC pipe because the fumes from the glue are
so toxic.  On a job site, by the end of the day, he said all the workers
were "high" from the solvent fumes.  I can attest to the nastiness of the
glues.  My recent electrical work was much more pleasant because I avoided
PVC conduit and the glue that goes with it.

In the larger picture, there have been reports that steel recycling mills
can be very high emitters of dioxin, I think because they use feed material
that is contaminated with PVC or chlorinated cutting oils or some such.
I'm not aware of whether anyone has looked into how much dioxin is released
on average when making steel.  I doubt it would be as much as is released
when making PVC, but it just goes to show you that everything we humans do
is likely to have negative impacts somewhere.

Chris Neurath