There are still other drawbacks on LCA's. An LCA is a investigation
of a certain moment and can be outdated rapidely, because of investments
in the factories. So are e.g. the emission of dioxins and other chlorinated
compounds from PVC factories to water reduced by a hundredfold in the past
ten years, just by introducing (biological) waste water treatments. The
same is true for air emissions.
Another problem can be that the differences in emissions between factories,
making the same products, can differ widely, where the difference can be
much wider than between factories making different products. In that case,
factories which have invested a lot in reducing emissions are punished,
because other ones didn't do that. In fact, average emissions for one type
of product should be accompanied with lowest and highest measured values
and with the possible lows when the Best Available Technology (BAT) should
have been used.
Energy and crude oil use for different materials.
All figures as GJ/ton for energy use and ton/ton for crude oil.
| Energy and crude oil use
for different materials |
||
|---|---|---|
| Material | energy
use |
crude oil
use |
| PVC | 53 | 0.63 |
| LD/HDPE | 70 | 1.10 |
| PP | 73 | 1.17 |
| PS | 80 | 1.26 |
| PET | 84 | 1.65 |
| PC | 107 | 1.68 |
| Steel | 30 | 0.00 |
| Aluminium | 200 | 0.00 |
As you can see, the energy and crude oil use of PVC is the lowest of
all plastics. Not bad for an energy guttler, isn't it?
Steel and aluminium don't use crude oil as raw material, but steel
needs coal and aluminium uses also coal and lots of electrical energy.
The amount of crude oil should not be overemphasised, all plastics in the
world do use only 4% of all crude oil, 94% is directly used for energy,
the rest for other purposes. So, if crude oil should only be used for making
plastics, it would be an abundant material...
It is quite normal that the energy and crude oil use of PVC is the lowest, because 57% of PVC comes from salt, an extremely abundant material on earth. Of course you need energy to split salt into chlorine and sodiumhydroxyde, but in many cases this is done by combined heat/energy power plants with very high yield on energy and you have two valuable products for the same energy. Sometimes you even have three products: chlorine is first used to make another product, like polycarbonate (PC) or polyurethane (PU), before it is used to make DCE/VCM/PVC. That means that in such cases the energy use of PVC and of the other products is even lower.
The energy use per ton is not the only point in total energy use during a lifetime: the amount of material, needed for a certain application, the type of use and the length of a usefull life is important too. Although aluminium needs much more energy for production, it saves much more energy when used for e.g. making car motors, because of the lighter weight. That means that you need less aluminium in weight to make the same motor and lighter cars, which gives less petrol consumption, thus energy (and pollution) savings during lifetime.
Critical volumes for the production of different materials.
All figures in m3 air/kg and dm3 water/kg.
| Critical volumes for the
production of different materials. |
||
|---|---|---|
| Material | c.v. air | c.v. water |
| PVC | 700 | 3,000 |
| LDPE | 265 | 1,650 |
| PP/HDPE | 325 | 3,685 |
| PS | 255 | 6,335 |
| PET | 180 | 8,000 |
| PC | 180 | 5,050 |
| Steel | 3,400 | 4,600 |
| Aluminium | 9,320 | 27,700 |
These figures are in fact not complete and outdated.
Not complete, because the energy emissions were not included. Why,
that was not clear, until we saw the difference: electrical power for salt-chlorine-PVC
plants is mainly produced by the use of natural gas, while most refinaries
use their own waste. This gives for the biggest refinary in The Netherlands
already 1,200 tonnes of soot per year for a work up of 21 million tonnes
of crude oil. As you know the difference in carcinogenity (and persistence!)
between soot and the most important polluters from a PVC factory: VCM and
DCE (see Chlorine and cancer), taking
into account the energy production would give a lot more air pollution
for the 100% oil based products!
Also outdated, because the DCE-VCM-PVC factories in The Netherlands
since 1991 have installed a lot of new equipment to reduce the air emissions
of DCE with a tenfold and of VCM with a fivefold, while not much changed
at the biggest refinary...
Of course, here too it is important, how much material you need for
a certain application and for some applications more important (e.g. aluminium
and plastics in cars), how much - or less - pollution is coming from the
use of these products.
Al together, the figures for PVC are not so bad for an environmental
poison, isn't it?
Of course, all good properties can turn into bad, if that is on behalf
of the environment. We have seen no big problems for PVC when produced,
there are even less when in use. PVC needs practically no maintenance.
This was one of the reasons for the Gothenburg (Sweden) hospitals to choose
for vinyl instead of linoleum floorings. Although the production of linoleum
uses near only renewable raw materials (linseed oil), it is less favorable
in use: before the application of vinyl they had to use 6 tons of cleaning
agents per year, after that, 0.5 tons and they will reduce it to near zero.
The same is thrue for wooden window frames: Wood is a 100% renewable
raw material, but, besides production emissions (2/3 of the wood ends as
production waste, which is mainly burned!), wooden window frames have to
be painted, or treated. This makes the use of wood and PVC for window frames
equally good (or bad) for the environment.
PVC was accused to have many negative aspects for health and environment.
In all cases these accusations turned out to be false.
PVC softeners, like phtalates, are linked to cancer and oestrogenic
properties. That may be the case, if you give massive doses to rats - up
to an equivalent of 500 g/day for an adult human - but after hundreds of
tests, not for primates (apes and humans), because differences in metabolism.
PVC, including phtalates, is the only thoroughly tested plastic which is
permitted for bloodbags. In fact, you ingest near 0.1 g of phtalates per
year by using PVC, the toxic equivalent of drinking 0.01 g of alkohol...
per year.
PVC was accused to give remaining VCM in food and water, which can
cause cancer, it turned out that water from PVC-bottles gives (an insignificant)
1.9% less cancer, compared with water from glass bottles in a mega-experiment.
PVC was accused to be the origin of sudden childrens dead, it turned
out to be the contrary: one of the many possible causes is the use of matrasses
which catch a lot of dust. PVC and other plastic layers prevent that.
PVC was accused to give irritations and allergic reactions, it turned
out to be the contrary: a lot of hospitals, especially build for allergy
patients are using PVC as building material, because a lot of natural materials
like certain types of wood and not well treated natural rubber (latex)
can give severe allergic reactions.
So we can go on... It is easy to find new allegations every day, so
you can accuse anything to be an 'environmental poison', because it takes
months, even years to prove that the allegation was false. The general
public in the meantime will remember only the allegation which was widespread
in newspapers and other media. The positive results, months or years later,
are in general not even mentioned, or somewere on the twentieth page...
You are at level two of the Chlorophiles pages
Created: March 16, 1996.
Last update: September 18, 2001.
Complete Life Cycle Analyses of PVC and alternatives in applications
For any comment on this page, especially on the Life Cycle of materials or on other Chlorophiles pages:
chlorophiles@pandora.be
