Uneasy about Nonstick Cookware?

Written: 5/2005

Is it safe to use your nonstick pan on high heat?

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.

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.

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.

Reprinted with permission from the May/June 2005 issue of Cook’s Illustrated magazine.

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