http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2005/06/15/FDGMFD2KM01.DTL
San Francisco Chronicle
June 15, 2005
The Sticking Point
Nonstick pans are a boon to cooks, but are there dangers lurking
beneath the surface?
By David Rubien, Chronicle Staff Writer
[Excerpts. This is not the full article]
Cooks who appreciate the almost-magical properties of nonstick
frying pans will be happy to know that the products have gotten
a lot more durable. Unfortunately, so has the controversy surrounding
the chemical behind the nonstick magic.
Pots and pans coated with Teflon -- or any of the surfaces analogous
to Teflon -- are immensely popular. U.S. consumers spent roughly
$1.2 billion on 159 million pots and pans last year, 60 percent
of which were nonstick, according to figures from the Cookware
Manufacturers Association.
"Nonstick has revolutionized America's cooking habits over
the past generation by letting consumers cook with much less oil
and grease and by easing the cleanup chores associated with cooking,"
says Hugh Rushing, vice president of the association. "Nonstick
cookware is now mainstream for the majority of U.S. consumers.
It's found on high-end cookware as well as medium- and low-priced
product."
Decent nonstick frying pans made by companies like T-Fal, Faberware
and Revere are widely available in models ranging from $10 to
$30. Yet scientific studies, not to mention lawsuits (see story,
F4), suggest that there's another kind of price associated with
nonstick: The pans may be bad for you. They can give off potentially
harmful fumes at medium to high temperatures, and a chemical crucial
to the manufacture of nonstick surfaces -- but not found in the
finished surfaces -- is prevalent in the environment, including
most Americans' blood.
"We recommend that people phase out
the use of Teflon cookware in their home," says Lauren Sucher
of the Environmental Working Group, a Washington, D. C.,
organization that compiles data on toxicology.
Teflon is a registered trademark of the DuPont Co., which has
been making Teflon cookware and other products for more than 40
years. The company says nonstick pans are completely safe if used
according to manufacturers' instructions, and that emissions from
DuPont factories have virtually ceased.
"Believe me, you get more toxic fumes
from the food you're cooking than from the pans themselves,"
says Dave Boothe, strategic planning manager for fluoropolymer
solutions at DuPont.
The dominance of nonstick is not surprising, particularly now
that the pans don't flake and divot like earlier generations of
pans, many of which can still be found cluttering the cabinets
of America's kitchens. If the average nonstick frying pan from
20 years ago is like a whitewashed shack, today's pans are akin
to modern condos with deluxe paint jobs. Paint is often the simile
used to discuss the making of nonstick pans, because the nonstick
material is essentially painted onto the surface of the pan.\
Although the technology has improved dramatically, the essential
nonstick ingredient is the same as it was when a DuPont Co. chemist
discovered it in 1938. The waxy substance he scraped out of a
freon cylinder turned out to be the most slippery substance in
the world. Called polytetrafluorethylene, or PTFE, it consists
of a chain of carbon atoms that are surrounded by fluorine atoms.
Dupont began manufacturing PTFE, trademarking it Teflon.
In 1954, a French inventor figured out a way to bond Teflon to
frying pans, and formed a company called Tefal, which evolved
into T-Fal, a giant manufacturer of pans and other household appliances.
The early nonstick pans didn't hold up very well, however; they
began flaking within months. So Dupont and the few other companies
that also make PTFE coatings began experimenting with additives
to make PTFE stronger.
About 15 years ago, PTFE compounds improved dramatically. Nonstick
coatings now are enhanced with powders made out of ceramic, stainless
steel or titanium, and the coatings are applied much more thickly,
as well. The pans to which the surfaces are attached also are
much better, basically a function of bonding different materials
to aluminum, which is the best surface for nonstick, though soft
in its natural state.
"Reinforced nonsticks are resistant to scratching, many
invite the use of metal tools, and their useful life has increased
to years of daily use," Rushing says. "Nonstick's ability
to remain slippery over time has increased enormously in recent
years."
One of the reasons those old Teflon pans would flake and chip
is that utensils would dent the aluminum, thus undermining what
the Teflon was trying to hold onto. Nowadays, aluminum gets anodized,
an electro-chemical beefing-up process that makes the metal nonporous,
nonreactive and harder than stainless steel. The anodized metal
retains the natural superior heat conductivity of aluminum. Today's
pans can also be varying combinations of materials like aluminum,
stainless steel and copper to try to get the best of heat conductivity,
weight, look and cooking effectiveness.
As for how food turns out when cooked in nonstick pans versus
conventional pans, that's a subjective matter. The Chronicle's
own test of some nonstick pans provides some illumination, as
do the opinions of some professional chefs (see accompanying stories).
Experienced chefs who use nonstick pans know that they are good
for certain things, like making crepes, but not for other things,
like searing meat. But the same could be said for other pans --
for example, cast iron isn't good for cooking anything acidic,
nor would you want to grill a kielbasa in a wok. For some cooks,
using nonstick -- or not -- boils down to picking the right tool
for the job.
Still other cooks may avoid Teflon altogether because of safety
concerns. A letter to Dear Abby that ran in The Chronicle on May
7 from a distraught "Bob in Atlanta," was a cautionary
tale about a beloved 26-year-old Amazon parrot who died from exposure
to fumes emitted by a burned Teflon pan.
Bob's parrot perished from a syndrome known as Teflon toxicosis,
which results from overheated PTFE-coated pans and has been recognized
for decades. That's why instructions packaged with nonstick cookware
say that pans should never be left empty over a flame. Birds have
extremely sensitive respiratory systems.
DuPont says that off-gassing from nonstick pans does not occur
until the pans are heated to over 400 degrees, in which case,
at worst, fumes can lead to brief flulike symptoms in humans,
called polymer fume fever.
DuPont scientists point out that birds can die from many different
types of fumes, including those produced by burning onions or
butter.
"Anything that's degraded thermally, whether it's food,
wood or plastic, will give off toxic gases," says DuPont's
Boothe.
The Environmental Working Group has collected data from several
industry, government and academic studies that have been done
on off-gassing of PTFE- coated pans heated to various temperatures.
The tests revealed that more than a dozen
types of potentially toxic particulates -- including hexafluoropropene,
hydrogen fluoride and difluoroacetic acid -- are released. But
whether the fumes occur in enough quantity to harm humans has
not been determined.
"DuPont says that gasses aren't released in normal use,
but academic and peer-reviewed studies show that pans get hot
enough to release toxic gases at normal cooking temperatures,"
Sucher says. But pan fumes are nothing compared to the heat DuPont
has gotten over environmental contamination (see story, above).
It's not clear whether health and safety considerations have any
effect on sales of nonstick cookware.
"(PFOA) has been used to manufacture millions -- probably
billions -- of pans, and we don't see evidence that anyone is
injured by their use," says Boothe. "That's a pretty
good safety record." ...
Chemical exposure lands Teflon maker in hot water
DuPont has been subjected to three major lawsuits over alleged
pollution by a chemical that's necessary to manufacture Teflon.
Perfluorooctanoic acid (PFOA), or C-8, is used to smooth out
PTFE, which tends to be clumpy in its natural state. Shown to
cause birth defects in animals, C-8 is estimated to be in the
blood of more than 90 percent of humans, although in levels below
what is thought to be dangerous, according to recent studies.
The chemical also is prevalent in normal household dust.
DuPont studies, including a recent peer-reviewed analysis, indicate
that C-8 is not present in Teflon itself -- the chemical is eliminated
in the heating process that bonds the Teflon to the pan. But there's
no question C-8 is out there in the environment.
DuPont's legal troubles over C-8 began in the late '80s when
Wilbur Tennant, the owner of a family dairy business in Parkersburg,
W. Va., saw almost 300 of his cows sicken and die. He suspected
it had something to do with the creek water they drank, and discovered
that a nearby DuPont plant was dumping waste into the water.
Tennant sued, and documents uncovered in the trial showed that
the chemical company was indeed dumping C-8 into the stream and
had been aware for 20 years that C-8 was potentially hazardous.
DuPont and Tennant settled in 2001 for an undisclosed amount,
but the case triggered a much bigger lawsuit, this time a class-action
effort filed by 50,000 West Virginia residents claiming contamination
of their drinking water.
That suit, in turn, brought on an investigation by the Environmental
Protection Agency. In February, DuPont paid out $107.6 million
in settling the class-action suit. The EPA case is still pending,
although DuPont recently admitted that it hid medical data for
20 years, and may have to pay up to $300 million in fines, according
to the federal agency.
Last month, the U.S. District Court for the District of Columbia
subpoenaed DuPont for documents pertaining to C-8 as part of a
grand jury investigation, Bloomberg.com reported.
DuPont is the third-largest chemical company
in the world, with $1.8 billion in income last year, and
$200 million in profit from Teflon sales, according to Hoover's
business database. DuPont maintains it has reduced PFOA emissions
by 98 percent by treating wastewater and scrubbing air, and it
is now sharing proprietary information with other companies on
how to eliminate the chemical...
©2005 San Francisco Chronicle
[Note from FAN: see
2003 newspaper account on the Tennant farm]
