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A review of the data generated in Europe shows the vinyl industry
as a minor contributor to dioxin levels. Vinyl constitutes only
1% of the total chemical processes in general and hence represents
only about one half of 1% of the dioxin source. The dioxin levels
found in vinyl production are comparable to the amounts present
in grass or soil and pose no threat to human health.
The vinyl industry's voluntary dioxin characterization program
for reassessment of dioxin levels further confirms vinyl's minimal
contribution to dioxin emissions. Sampling data from various
points in the vinyl production process show emissions of about
24 gms. of dioxin to air, land or water or less than 1% of the
3000 gms that the EPA estimates are emitted annually by sources
throughout the country. The recent dioxin source inventory shows
the most dioxin coming from municipal waste incinerators, backyard
trash burning, landfill and forest fires. [Vinyl and the Environment
-Environmental Briefs - December 1999]
The US Environmental Protection Agency has always contained
one mystery: the signal of the existence of a large "unknown"
source of dioxin. One of these mystery resources is located
to backyard trash burning. An increased amount of vinyl in the
trash barrels did not produce high amounts of dioxin. Further,
the design and the operating conditions of the incinerator and
not the vinyl content of the waste are the determining factors
in dioxin generation and emission. [Vinyl and the Environment
- Environmental Briefs - July 1999]
Greenpeace and the other environmental groups accuse the chlorine
industry to be the main source of dioxins in the environment.
But, the whole chlorine industry and the PVC industry are only
a minor source of dioxins today. The most important sources
are the incinerators.
The amount of PVC or chlorine plays no important role in the
amount of dioxins formed at incinerators. From more than seventy
experiments at municipal incinerators, all over the world, there
is evidence to prove that there is no relation between chlorine
input and dioxin emissions.
On a production of 500,000 tonnes per year, about 4 gms of dioxin
was formed. This is 500 times lower than the figures suggested
by Greenpeace. After cleanup in a biological wastewater treatment
and the incineration of the sludge of the waste treatment and
the off-gases, about 40 milligram of dioxins are released to
air and about 10 milligram are released to water per year. Thus,
only 30 to 80 milligram of dioxins per year are released from
a PVC factory producing hundred thousands tons of PVC. Nowadays,
the dioxin levels are the same as much in 1945, even though
the chlorine and PVC production is enormously higher than in
those times.
Enclosed is an endorsement from ECVM removing some of the fears
on dioxin coming from PVC.
PVC AND FIRE
PVC Polymer because of its chlorine content is inherently
fire resistant. In fact among all the common polymers, PVC
is the most resistant to fire. Not only it is better than
the common plastics, it certainly shows some interesting advantages
over conventional materials like wood. The self ignition as
well as flash ignition temperatures of PVC Polymer as well
as rigid PVC Products like window profiles having more than
80-85% content of PVC polymer are almost 150° C higher
than wood clearly indicating that PVC would be more resistant
than wood to initiate fire on its own or when heat is increased
due to fire emanating from other sources. For spreading of
fire, oxygen is essential - PVC polymer and Products used
in infrastructure/buildings like pipes, conduits, profiles
or even flooring and wires/cables have limiting Oxygen Index
ranging from 30 to 50 compared to 21 present in normal atmospheric
conditions or 21 limiting Oxygen Index of wood. It is therefore
quite natural that all the building institutes around the
world not only approve such PVC products for building/infrastructure
but also provide it the highest ranking among the alternate
materials that can be used for such applications.
In fact, rigid PVC products generally extinguish by themselves
once the fire source is eliminated.
It requires high temperatures, continuity of fire and abundant
supply of fresh oxygen to sustain fire in these PVC products.
PVC products tend to provide some benefits in fire situations.
First of all burning of PVC tends to reduce or maintain heat
instead of increasing it. Secondly, when PVC burns, it releases
hydrogen chloride and relatively small amount of carbon monoxide.
Generally other materials on burning tend to produce carbon
monoxide which is odorless but very toxic. Hydrochloric acid
which has irritating smell warns the victims even when it
is present in small quantity. Due to these two distinct benefits
the fire authorities favour PVC products.
Experiments conducted by Boston Fire Dept. as well as Harvard
University have shown that in a typical building fire HCI
levels did not exceed more than 300 ppm. At such levels, there
is no danger to human/animal fire victims.
Hydrogen Chloride being corrosive was thought to contribute
to corrosion of concrete structure. However large scale experiments
have proved that HCI emitted in fires from PVC products do
not corrode such structures.
EFFECT OF PHTHALATES
Phthalates are among the most studied materials in this world.
Based on the best evidence to date, the producers of phthalates
strongly believe that these products are safe and pose no
risk to children or adults properly using products containing
phthalate esters.
Phthalates are important since they make plastic flexible.
These phthalates have undergone extensive health and safety
testing. A phthalate commonly used in children's toys is DINP.
There is an extensive database that includes test results
from studies that examined possible liver and kidney effects,
cancer , reproduction and development as well as endocrine
modulation. Based on the extensive date available, there is
no scientifically validated evidence that shows that the use
of phthalates in human toys poses a human health risk. The
Phthalate Esters Panel stands by the extensive research and
testing that shows that phthalates in toys are safe for intended
use. The Consumer Products Safety commission has stated that
the amount children may ingest does not reach to harmful levels.
[Phthalate Esters Panel - November 2000]
DBP exposure in people was recently studied by the Centers
for Disease Control and Prevention (CDC). Results were consistent
with prior levels of exposure. The average DBP exposures were
more than 60 times below the level mentioned by the US EPA.
There were earlier claims that the presence of plasticizers
in vinyl flooring and wall covering could lead to childhood
asthma. These claims have been discredited by the Institute
of Medicine of the National Academies Of Science. The researchers
have placed plasticizers in the study's lowest category claiming
that they could find only insufficient evidence. [Vinyl and
the Environment - Environmental Briefs - May 2000].
In addition, phthalate esters have been shown to be readily
biodegradable in tests conducted using a number of different
protocols. In addition, the phthalate esters are easily photo
degraded and biodegraded and hence they do not tend to persist
in the environment.
A blue ribbon panel headed by Surgeon General C. Everett Kopp
has declared that vinyl toys and medical products made with
phthalate plasticizers are not harmful to children or adults.
In fact, the panel has revealed that the use of phthalates
in some medical devices makes them safer than alternative
materials. Dr. Koop has reassured that the use of vinyl toys
and medical products are safe. [Vinyl and the Environment
- August 2000 briefs]
All aspects of the toxicology of phthalates are currently
being assessed in a number of international forums, the most
important of which are outlined below :
The Scientific Committee on Toxicity, Eco toxicity and the
Environment (CSTEE) has issued opinions on the migration of
phthalates from soft PVC toys and childcare articles in April
and November 1999. In these opinions it has evaluated the
extensive toxicity data available on the phthalates, identified
No Observable Adverse Effect Levels (NOAEL) and, after applying
a safety factor of 100, defined Tolerable Daily Intakes (TDI)
for each of six phthalates. The TDI values have been coupled
with a worst case exposure scenario to give guidance values
for migration. If the guideline values are not exceeded then
these phthalates can be used safely.
Thus all toxicological concerns have been taken into consideration
by the CSTEE and they have concluded that the listed and assessed
phthalates can be used safely in toys provided that the guideline
values for migration are not exceeded.
United States Consumer Product Safety Commission (CPSC). The
CPSC has evaluated the potential health risk to children under
3 years of age from teethers, rattles and toys made from PVC
containing DINP. The evaluation included both in-vivo and
in-vitro measurement of the migration of DINP during mouthing.
Based on this migration data and the 'time of mouthing' information
obtained by the Dutch Consensus Group, the CPSC concluded
that "few if any children are at risk from liver or other
organ toxicity from the release of DINP from these products
[The Use of Phthalate Plasticizers in Soft Toys-Environmental
Briefs - April 2000]
Hypothesis on endocrine disruption and other health issues
(ECVM report)
A number of scientific papers have given rise to concern about
a possible general reduction in male sperm counts and other
reproductive disorders. These have resulted in a hypothesis
that certain products in the environment which mimic the natural
female hormone oestrogen may be the cause. This has become
known as the hormone - or endocirne - disruption theory. However,
there is no study based on sound science that shows this actually
occurs.
Extensive research is being carried out by the chemical industry
and others in Europe, the United States and elsewhere, into
endocrine disruption theory. Phthalates have been implicated
as one of a number of possible hormone-mimicking chemicals
but they are not the only substances under scrutiny along
with many naturally occurring substances (phyto-oestrogens)
found in plants and vegetables.
Concerns have been raised about a possible endocrine effect
of some phthalates, although the most recent studies, which
include in-vitro and in-vivo tests on DEHP have shown that
there is no reason that the suspected phthalates would produce
oestrogenic effects in humans.
It is, therefore, very unlikely that any significant risk
to human reproductive health is associated with phthalate
use. However, they continue to be rigorously researched and
scientifically
assessed to confirm they are safe to use and pose no threat
to health or the environment. Such assessments are currently
being undertaken on five phthalates (DBP, DEHP, DINP and BBP)
under the EU's Risk Assessment Procedure (Council Regulation
[EEP] 793/93).
While the International Agency for Research on Cancer (IARC),
part of WHO, used to classify DEHP as "an agent possibly
carcinogenic to humans", this was based only on rodent
studies and did not take into account more recent understanding
of the underlying mechanisms. It has now changed its classification
of DEHP to "not classifiable as a human carcinogen"
based on existing scientific evidence that supports the safety
of DEHP as a component of PVC medical products.
In addition the Specialized Experts Working Group of the European
Commission has concluded that there is no evidence to warrant
classification of DEHP as a carcinogen.
Recently three independent panels convened by Baxter Healthcare
Corporation confirmed that DEHP does not pose a human cancer
risk.
With regard to cancer, it is important to note that since
1980 a large number of investigations have shown that feeding
high levels of phthalates to rodents over their lifetime causes
a large increase in microbodies in the liver called peroxisomes.
This 'perixisome proliferation' leads to the formation of
liver tumors. However, when these chemicals are given to non-rodent
species such as marmosets and monkeys (primates considered
to be metabolically closer to humans), such liver peroxisome
proliferation and liver damage is not seen. The changes seen
in rats are therefore likely to be a species-specific effect.
The European plasticiser industry (represented by the European
Council for Plasticisers and Intermediated - ECPI) is conscious
of the genuine public concern which now exists around the
use of phthalates and takes this very seriously. The industry
is in favour of a public debate, and considers that it has
a duty to respond to public concern by ensuring that there
is an open exchange of information about the performance of
its products. Clearly, if there were evidence that any single
product presented a serious health risk, the plasticiser industry
would have no hesitation in withdrawing it.
The industry is also committed to supporting and, where appropriate,
commissioning further scientific research to make sure that
the current use of phthalates poses no hazard to the health
of people or the environment.
VINYL RECYCLING
Vinyl is primarily derived from salt which is a virtually unlimited
natural resource. The process of manufacturing vinyl has minimal
releases to the environment. Because vinyl is so durable, its
use on long - lived applications provides additional resources.
When vinyl products do reach the end of their lives, they can
be recycled into other useful products.
Even after a useful span of decades, vinyl products can be recycled
into new applications lasting decades more. In the US, more
than 3,500 communities accept vinyls in their recycling program.
More than one billion pounds of vinyl were recycled from post-industrial
and post-consumer sources in 1999, disclaiming the claims that
vinyls cannot be recycled. Independent consulting firm Principal
Partners have found that nearly all scrap is recycled back into
the vinyl manufacturing process resulting in a notably high
resource-efficient process. The plastics such as those used
in milk jugs and soda bottles have higher recycling rates because
of the presence of vinyl. The industry has helped develop the
equipment that automatically separates vinyl from other post-consumer
plastic packaging and expand recycling for non-packaging waste
such as construction and demolition scrap. The use of incineration
facilities together with the associated energy plays a complementary
role to recycling and has allowed to reduce the volumes going
into landfill.
Just one year after the Autovinyl recycling initiative began
its activity of the recycling of automotive scrap, the coalition
of the French Vinyl, automobile and equipment manufacturers
was successful in its interim goal of recycling 5000 metric
tons of vinyl the group reported that 1740 metric tonnes of
automotive vinyl production scrap and vinyl products from end-of-life
vehicles have already been processed by the recycling companies.
Now, the company is focusing its initiatives to developing new
products form these recycled material in the automotive industry
and other sectors. By 2002, the coalition expects to be recovering
80 % of all vinyl automobile parts.
Ten vinyl manufacturers in Europe have teamed up to build a
pilot plant to evaluate the technologies for vinyl recycling.
The project is being funded by members of the European Council
of Vinyl Manufacturers.
Solvay has recently announced a new technology called vinyl
loop for recycling vinyl compound- based products. This process
uses a solvent to separate vinyls from other materials such
as polyester found in applications like architectural canvas
and tarpaulins. The process is also found to be useful to recycle
vinyl compounds from cables, pharmaceutical blister packs, floor
coating and car dashboards. Meanwhile, Japan's Toll Corp. announced
recently a technology to recycle carpet panels and vinyl floor
covering. The recovered wall covering is used to manufacture
flooring and the carpet is recycled into new carpet material.
PVC AND MUNICIPAL WASTE INCINERATION
The amount of PVC in municipal (household waste is less than
1 %. Then PVC is combusted, it is converted into carbondioxide,
water, hydrogen chloride and metal chlorides. However PVC provides
considerably less Co2 for kg. of materials than the combustion
of other materials such as oil, wood, and coal. PVC therefore
makes smaller contribution in both green house effect. HCL is
a hazardous acid gas which must be removed from the emissions
of all municipal; and industrial waste materials.
Dioxins - which are generated as by products from industrial
and combustion process - can also be produced in waste incinerator.
However with advantage of modern incinerator technology, the
control of all hazardous emissions in a matter of safe and
effective operation of an incinerator.
There is some scientific evidence that PVC's presence in municipal
waste dream plays no special role in the amount of dioxin forced
and released from incinerators.
Another comprehensive study by the Association of plastics manufacturers
in Europe (APME) into combustion of mixed plastic waste and
municipal solid waste of the Würzburg incineration plant
in Germany demonstrated that increasing the overall contact
of waste plastics is including PVC - did not produce any measurable
increases in the production of dioxins and furans. All gaseous
emissions recorded during the project completed at German emission
standards.
CONCLUSION
The Global PVC production capacity in the year 2000 is 68 Bn
Lbs ( 31 M MT) During the next five years ( i.e 2000 - 2005)
, the world demand of PVC is expected to grow at an average
growth rate of 4.7% This will take the Global per capita consumption
of PVC to over 10 kg. Despite their maturity, substantial growth
per capita remains in North America(> 40 kg) and Western
Europe (> 30 kg).
TO WHOM IT MAY CONCERN
STATEMENTS ON PVC AND DIOXINS
The European Council of Vinyl Manufacturers (ECVM) represents
the PVC producing industry, including the production of monomer,
at European level. Its membership includes in companies representing
98 % of Western Europe's PVC production. A major responsibility
of ECVM is to monitor co-ordinate and promote programmes within
the industry in order to assess the environmental impact of
PVC on the environment, to develop the use of best environmental
practices and to facilitate eco-efficient solutions for waste
management and recovery.
In relation to the issue of dioxins we can make the following
statements:
Manufacturing of PVC and of its monomer
1) Formation of very small quantities of dioxins only occurs
in one of the process steps leading to the production of vinyl
chloride, the monomer of PVC. These dioxin molecules are absorbed
by the solid catalyst and hence are easily contained by filtration
and destroyed by appropriate treatment of this catalyst.
2) Small quantities of dioxins could also be produced when incinerating
chlorinated waste products, especially dioxin-containing heavy
ends. However, this is the case for any incineration of chlorine
containing organic material (also household waste) and is suppressed
by adequate equipment and operating conditions.
3) The production of PVC itself and of PVC-based products takes
place at temperatures far below those required for dioxin formation.
The PVC production chain is consequently only a very minor contributor
to dioxins' emissions throughout the world (much less than 1%)
and this amount is regularly decreasing.
Incineration of PVC products
The European Union Commission published in July 2000 a Green
Paper on the Environmental Issues of PVC. The Commission states
that: "it has been suggested that the reduction of the
chlorine content in the waste can contribute to the reduction
of dioxin formation, even though the actual mechanism is not
fully understood. The influence on the reduction is also expected
to be a second or third order relationship. It is most likely
that the main incineration parameters, such as the temperature
and the oxygen concentration, have a major influence on the
dioxin formation". The Green Paper states further that
"at the current levels of chlorine in municipal waste,
there does not seem to be a direct quantitative relationship
between chlorine content and dioxin formation".
These views are based on more than ten in-depth studies carried
out in various parts of the world.
In summary, one can be fully confident that dioxin formation
in Municipal Solid Waste Incinerators is not related to the
amount of PVC. Variations in combustion conditions are the most
important parameter for the formation rates of dioxins in MSW
incinerators. Removing PVC from Municipal Solid Waste would
not reduce dioxin formation.
Yours faithfully,
A.Sevenster
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