Cook's Illustrated, Chris Kimball
Published April 5, 2005
First made available in France in the 1950s, nonstick cookware soon
made its way to America, appearing on the market here in late 1960 as
the "Satisfry" skillet. As in France, it was a huge hit with
consumers. By mid-1961 orders to the manufacturer, T-fal (still in
business today), had reached 1 million per month. Few kitchens today
are without at least one nonstick pan. In 2004, according the Cookware
Manufacturers Association (CMA), nonstick cookware accounted for 50
percent of all cookware sales.
Yet almost from the moment nonstick cookware came on the market,
rumors began to circulate that it was "unsafe." Concerns then were
similar to those today, focusing on the health effects for consumers
about fumes emitted from the cookware during stovetop use and the
health effects for workers involved in the manufacture of nonstick
coatings.
The information provided below is confined to concerns most relevant
to our readers: home cooks who use nonstick cookware.
HEAT AND FUMES
In the May/June 2005 issue of Cook's Illustrated, we reported the
results of kitchen tests in which we exposed both cheap and
good-quality nonstick pans to high heat on the stovetop and under the
broiler. Cookware industry guidelines recommend that the pans not be
used at temperatures above 500 degrees Fahrenheit; at 600 degrees, the
coatings can begin to emit fumes. We wanted to see if the cookware
would get this hot when used in recipes that call for high heat. We
found that it did. Here's a little more detail on aspects of the test
results we didn't have room to publish in the magazine; more
information is also provided on the effects of inhaling fumes released
by nonstick coatings at high temperatures.
Food can modulate pan temperature:
While our tests showed that in cooking a stir-fry over high heat pan
temperatures did rise above 600 degrees, neither the cheap pan nor the
expensive pan remained at 600 degrees in any one spot for more than a
second or so. The temperature, taken with an infrared thermometer gun,
rose and fell by as much as 200 degrees from one spot in the pans to
another and within the same spot in a matter of seconds. Moving food
over an empty spot would cause pan temperature to fall. When we heated
the pans empty over high heat, however, the temperatures rose to above
600 degrees and stayed there.
This result didn't surprise Dr. Mitchell Cheeseman, director of the
Center for Food Safety and Applied Nutrition, the division of the U.S.
Food and Drug Administration that is charged with, among other things,
determining the safety of food additives. (Yes, Teflon and its
components are considered safe "food additives"; it's acknowledged
that the nonstick coatings on pans do deteriorate and that anyone who
eats food cooked in these pans may consume those particles, which are
judged to be "inert" by the FDA, passing through the gut undigested
and unchanged.) Cheeseman explained: "I wouldn't expect that you could
sustain temperatures of 600 or 700 degrees with food in the pan. If
you did, the food would be charred to the point of being inedible.
Food contains water, and water will mediate the temperature of the
pan." (It's also the case that the readings of the infrared gun used
to monitor the pan temperature are less reliable when there's food in
the pan; the gun is most accurate when used on the smooth dark surface
provided by an empty pan.)
Cheeseman's interpretation of our results reinforces the
recommendation we made in the magazine about use of nonstick cookware
over high heat: The worst thing you can do is heat an empty pan on the
stovetop. Always add butter or oil first. Butter begins to smoke at
about 350 degrees, most vegetable oils between 400 and 450
degrees--before the pan reaches temperatures at which the coating
begins to break down. And never leave a pan--empty or not--unattended.
Likewise, a pan filled with the contents of a stir-fry intended to
serve four will be much less able to sustain high temperatures than a
pan of the same size used to cook a single lonely hamburger or chicken
cutlet. Use a pan size appropriate to the amount of food being cooked.
The effects of fumes:
The primary health concern for a person exposed to fumes released from
nonstick cookware is called polymer fume fever. the symptoms are
similar to those of a cold or flu, including coughing, difficulty breathing, and headaches, and they generally disappear after a couple
of days. Cases of polymer fume fever have been well documented among
people who work in plants that manufacture fluoropolymers--the name
for the compounds, consisting largely of carbon and fluorine, used to
make nonstick coatings. Polymer fume fever has been more difficult to
document among home cooks.
According to representatives from DuPont, maker of Teflon, an empty
pan would have to be left over high heat and maintain temperatures of
600 to 700 degrees for more than 15 minutes in an unventilated room
before a Teflon coating would emit enough fumes to make someone sick.
The other argument made as to why few cases of polymer fume fever in
the home have been documented is simply that they are difficult to
document--for one, because the symptoms are hard to distinguish from
those of colds and flus, for another, because many people with these
symptoms don't consult a physician. In short, neither the person nor
the person's doctor is ever aware that the symptoms indicate anything
other than a cold or flu.
The fumes from nonstick cookware can also be harmful--even lethal--to
birds, whose small size and highly rapid and efficient respiratory
systems make them much more vulnerable than human beings (the reason
canaries were so famously used in coal mines to detect the presence of
toxic gases). As veterinarians warn and as many bird owners know,
their pets' sensitive respiratory systems also make them vulnerable to
the more common household occurrences of fumes from burning butter or
oil, aerosol sprays, and tobacco smoke. Using an oven's self-cleaning
function can release fumes harmful to birds, and even the relatively
small amounts of natural gas released when an a pilot light goes out
can be cause for concern. The kitchen, in particular, is not a good
place for a pet bird.
BEST ALTERNATIVE TO NONSTICK COOKWARE
We continue to use nonstick cookware in the test kitchen, but for
anyone who is looking for an alternative, we've found cast iron to be
the most effective. Over time, cast-iron pans develop nonstick
properties as the oils and fats used in cooking polymerize (the
molecules change shape and link up) and essentially fuse with the
surface of the pan. How much time? Clearly, the older and more
seasoned the pan, the more "nonstick" it will become--as anyone who
has been lucky enough to inherit their grandparents' cast-iron skillet
will tell you. For the rest of us, it's never too late to start.
Cast iron is heavy, of course, and it's not maintenance-free. It
should be seasoned upon purchase, used frequently thereafter (whenever
you want to fry up some bacon or a steak), and cleaned and cared for
properly. For information on seasoning and caring for cast-iron
cookware, click here. Cast-iron cookware is available in many
department, hardware, and cookware stores. To purchase a pot or pan
online, we suggest that you visit Lodge Manufacturing. Lodge sells
both seasoned and unseasoned cookware. In kitchen tests, we found that
the preseasoned cookware (Lodge Logic and Lodge Pro-Logic) had better
nonstick properties than the unseasoned cookware, but its performance
did not come close to that of pan seasoned over years of use. For the
complete results of these tests, click here.
