Perfluoro-octanoic acid (PFOA), an ingredient of Teflon and also
known as ‘C-8’, is a suspected carcinogen now found
in humans, other animals and plants in the US, Europe and Asia.
PFOA is very persistent. Released into the environment it looks
as if it will take literally millions of years to biodegrade.
The company ‘3M’ (which once manufactured PFOA) found
that it took 4.4 years for just half of it to be excreted from
Where does it come from?
Some PFOA is released during the manufacture of Teflon, but it
is thought that the majority is given off when pans and trays
with Teflon coatings are heated to normal cooking temperatures
and, of course, especially when allowed to overheat or burn dry
in error. The average levels of PFOA (now found in 96% of Americans)
are fivefold higher than can be attributed to releases from the
chimneys of chemical company DuPont’s Teflon factories.
The latest DuPont studies show that Teflon emits toxic PFOA gas
particulates at 446° Fahrenheit (F), but the lowest temperature
linked to emissions by an independent study is 325°F.
(This was the temperature reached by an oven with a Teflon
coating when baking biscuits.) In one case where this occurred,
all the baby parrots in a cage in the owner’s kitchen died.
DuPont does warn that fumes from cookware with teflon
coating can be fatal for birds but, despite even its own evidence
(see below), continues to deny that any emissions occur below
temperatures well above those normally used for cooking. Dupont
has also suggested that it is the fumes from the fat in highly-heated
pans, rather than those from the Teflon coating itself, which
are to blame for bird deaths. However, the biscuits which caused
the parrots' deaths were being baked without oil.
In common domestic cooking, like frying bacon or pre-heating
pans to make pancakes, temperatures often reach 536°F/280°
Centigrade (C).  In recent tests
a generic frying pan with Teflon coating preheated on a conventional
electric stovetop burner reached 736°F in three minutes and
20 seconds, with temperatures still rising when the tests were
terminated. A frying pan with a Teflon coating reached 721°F
in just five minutes under the same test conditions.
A third source of PFOA is waste incineration, which operates
typically at 680°F/360°C. Teflon is used in shatter-proof
light bulbs, heat lamps such as those used in factory farming
and sealants used in military machinery. Teflon-like compounds
known as ‘fluorinated polymers’ (FPs) are used in
grease-resistant food wrappings and containers (like Tetrapack
cardboard drink and soup containers), stain-resistant textiles,
carpets and papers. Although PFOA is not used in the manufacture
of FPs, it is created and released when FPs are heated to 680°F.
As yet, no-one knows how.
Researchers have found that Teflon heated to 680°F also emits
other toxic fumes, including TFE (tetrafluoroethylene), HFP (hexafluoropropene),
OFCB (octafluorocyclobutane), PFIB (perfluoroisobutane, a chemical
warfare agent ten times more toxic than phosgene, a chemical warfare
agent used during World Wars I and II), carbonyl fluoride (the
fluorine equivalent of phosgene), CF4 (carbon tetrafluoride),
TFA (trifluoroacetic acid), trifluoroacetic acid fluoride, perfluorobutane,
MFA (monofluoroacetic acid) which can kill people at low doses,
SiF4 (silicon tetrafluoride), HF (hydrofluoric acid, a highly
corrosive gas) and particulate matter. 
How serious are the health implications?
The fact that PFOA is often fatal for birds tells us nothing,
of course, about its dangers for humans (as a different species),
but we do know that inhaling PFOA damages human health.
A recent study found that cancer rates in the neighbourhood of
DuPont’s Parkersburg (Virginia) chemical plant are over
twice the US average. Elevated rates of prostate, cervical and
uterine cancer, as well as of rarer cancers like non-Hodgkin’s,
leukaemia and multiple myeloma were identified. Increased rates
were also found in plant employees.
Recently uncovered internal Dupont documents, kept secret by the
company for 22 years, revealed that pregnant workers exposed to
PFOA passed it to their unborn children, where it significantly
raised the risk of birth defects, particularly involving the eyes.
DuPont accepts that over-heated cookware with a Teflon coating
releases tiny chemicals which penetrate deep into the lung and
cause a ‘flu-like illness. Headaches, chills, backache and
temperatures of 100-104°F usually last for two days. The true
rates of ‘Teflon flu’ and the temperatures required
to release the fumes which cause it have never been properly established.
Teflon ‘flu rarely appears on doctors’ records because
its symptoms are very similar to common ‘flu and awareness
of a possible connection is extremely low.
A 17-year study covering 35 workers at an Italian chemical plant
showed a potential link between blood concentrations of PFOA and
a slight rise in cholesterol levels. The significance of the finding
is uncertain. Dupont was quick to point out that (i) no adverse
health effects had been reported and (ii) the blood PFOA levels
found were 180 times higher than found in US Teflon factories
(500 parts per billion) and 18,000 times levels found in the general
US population (5 parts per billion).
As evidence of adverse effects accumulates, it looks as if perfluorinated
acids like PFOA will supplant DDT, polychlorinated biphenyls (PCBs)
and dioxin as the most toxic chemical contaminants ever produced.
Ed.- For reasons we can only guess at, it has taken fifty years
for the US Environmental Protection Agency (EPA) to take the potential
dangers of Teflon seriously. The first study showing that Teflon
emitted fumes when heated was published in 1955. 
A 1975 study established emissions from Teflon pans heated above
554°F.  That the Agency has
promised comprehensive research into the possible dangers and
is finally pursuing Teflon through the courts, alleging that it
criminally suppressed important health information, is in no small
measure due to a long, determined campaign by the US environmental
campaigning group ‘The Environmental Working Group’.
For further information visit website: www.ewg.org
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