- out of the frying pan ...
Perfluoro-octanoic acid (PFOA), 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 workers’ bodies.
Where does it come from?
PFOA, a member of the perfluorochemical (PFC) family, is an essential
ingredient of Teflon, the non-stick coating used in cookware.
Some is released during manufacture, but it is thought that the
majority is given off when the non-stick pans and trays are heated
to normal cooking temperatures and, of course, 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
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The latest DuPont studies show that the Teflon emits toxic particulates
at 446°F, but the lowest temperature linked to emissions by
an independent study is 325°Fahrenheit (F).
(This is the temperature reached by a Teflon-lined oven
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 non-stick cookware 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 non-stick 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 non-stick frying pan 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 Teflon non-stick frying pan 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 Teflon cookware 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.
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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