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tackle, but it was the most noticeable, as various
municipalities in the Western Cape, in just five years,
had already experienced significant wear and tear
caused by UV on the fittings that had passed the
initial standard.
“Previously, the standard demanded a test of 48
hours under UV, because it was based on international
standards for underground fittings,” says Snyman.
“Additionally, in Europe, they hide their pipes away
inside walls or fixtures. We run it out in the open, in
direct sunlight. Any old polypropylene would have
passed the initial test without modification. The new
standard calls for 2 000 hours of UV testing, which is
much more representative of the application of
the product.”
The fact that the fittings are to be used above ground
also impacted on the required thickness of the pipes.
“In the end, we found a European standard that
dictated thickness for the above-ground applications
and we based ours on that one. The end result is that
the necessary wall thickness has changed to become
thicker,” says Snyman, adding that the final challenge
was one with much more severe consequences for the
use of polypropylene in South Africa.
Snyman explains that perhaps polypropylene’s biggest
weakness is the way that the raw material acts in fire.
Polypropylene’s biggest
weakness is the way that the
raw material acts in fire.
now been published. This means that any company
still claiming to have SANS 721 accreditation is
incorrect and could fall foul of the Copyright Act
should SABS decide to act.
“Any action on these false claims will have to come from
SABS, because the SANS standards are a SABS mark.
I have my doubts, though, on whether SABS will be
effective on that. Based on past personal experiences,
they don’t always follow up on these things rigorously,”
explains Snyman.
He insists, however, that what happened with
SANS 721 is unlikely to be repeated. “I think SABS
got a massive wake-up call on this thing. Initially, I
believe they were hugely pressurised by one of the
polypropylene manufacturers and the thing was just
pushed through. Then suddenly there was evidence
that they hadn’t followed their own processes, which
is SANS 1 – Part 1, in terms of developing standards.
When that came to light, they realised they could be in
big trouble and did everything they could to bring us
as speedily as possible to the point where we are now,
with a new standard,” says Snyman.
“PVC is used in mining because when there is a
fire, it is self-extinguishing. It doesn’t burn easily
and even if it does eventually burn, the moment
you take away the heat source, it stops. Unmodified
polypropylene is the exact opposite: it burns easily
and carries on burning,” he says. “It was essential
that we consider this because it is coming against,
or even inside, your house.” Johnston is also happy with the way that things
eventually panned out, saying, “I’m very comfortable
with the ultimate process and the conclusion. I think the
SABS has done a lot of things wrong and faced a lot of
criticism, but the big thing is to put things right when
they go wrong. I think that SABS took a very difficult
situation and handled it quite well.”
As a result, the SANS standard insists that polypropylene
fittings only be used with PVC pipes. “If you use it with
PVC pipes, it doesn’t matter if it burns. The PVC will act
as a firebreak,” says Snyman. There seems to be agreement around the table that
the initial standard was a mess, but that this new
one covers the bases and does so from a strongly
defensible position.
“All the things we fixed had complaints about them in the
initial stages, but they simply weren’t looked at. This new
version addresses these problems,” he says. “Scientifically, on every single step we took in the
calculations, there was a scientific publication on which
our decisions were based. Nothing was thumb-sucked
or pulled out of thin air. There was a rationale behind
everything, and I think if anyone wants to challenge this
standard, we are in a far stronger place to defend it,”
says Johnston. PA
ON THE UPSIDE
The result of all the changes is that the initial
version has been withdrawn and the new one has
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January 2019 Volume 25 I Number 1