Called by its first commercial name, Teflon (trademarked by DuPont), polytetrafluoroethylene (PTFE) is a polymer with nonstick properties.

Its use is controversial in cookware, given that with exposure to high temperatures it emits gasses lethal to birds and carcinogenic to humans, according to several studies.

Teflon, a generic name derived from the commercial brand that the U.S. chemical company DuPont trademarked in 1944, is a polymer (reinforced molecular composition) similar to polyethylene.

Its most characteristic properties, like that of non-stickiness, result because in teflon the hydrogen atoms are substituted by fluorine. It has the lowest coefficient of friction of any known solid material.

It is an inert material, capable of working as an electric insulation and flexible structural component that isn’t affected by light, created in 1938 by a DuPont chemist.

Used first as a military material (it was used in the Manhattan Project, that later would develop the atomic bomb), teflon was first used commercially beginning in 1946. It is currently used:

• In coatings for airplanes, rockets and spaceships, due to the thermal changes it can withstand.
• In high resistance fabrics, like Gore-Tex.
• In medicine, it is used in prosthetics.
• It is used as a coating for electronics.
• In paints and varnishes.
• In products subject to corrosive environments, like hoses.

Teflon at high temperatures

More controversially, teflon has been historically used in non-stick frying pans and other cookware. The U.S. public watchdog group the Environmental Working Group (EWG), has published its findings on the behavior of this cookware at high temperatures:

• Gasses emitted by products using teflon are lethal for domestic birds. When the polymer known as teflon, including in a pan or pot, reaches temperatures above those recommended in its use (the limit is around 300 degrees Celsius), its molecular structure breaks down. It is then when, according to the Environmental Working Group, teflon emits toxic particulates that kill domestic birds and can provoke an undetermined number of human health problems.
• At temperatures, according to DuPont scientists, above 340 degrees Celsius (660 degrees Fahrenheit) “significant decomposition of the coating will occur”.
• Studies by the EWG show that teflon, at high temperatures, can emit lethal chemical agents, such as the nerve gas PFIB, used as a chemical weapon during World War II.
• At temperatures above 350 degrees Celsius, teflon emits up to 6 distinct toxic gasses, according to the scientific studies published by the EWG, two of those are carcinogenic, two atmospheric contaminants and MFA, a chemical agent lethal to humans in small doses.
• On January 30, 2006, the U.S. Environmental Protection Agency (EPA) published that teflon can cause cancer.

DuPont has claimed for the past five decades that teflon cookware does not emit dangerous chemical substances during “normal use”.

The company assures on their website that “DuPont non-stick coatings will not begin to significantly decompose until temperatures exceed about 660°F (349°C) – well above the smoke point for cooking oil, fats or butter.”

Consumer groups and media outlets have performed studies, like those of the Environmental Working Group, showing that the temperature stated by DuPont where the non-stick pans begin to offgas is reached fairly easily.

In the EWG study on a conventional, electric stovetop, their generic non-stick pan reached 736 degrees Fahrenheit in three minutes and 20 seconds, and rising when the test was terminated. “These new tests show that cookware exceeds these temperatures and turns toxic through the common act of preheating a pan, on a burner set on high.”

• Studies on the toxicity and hazards of teflon, in the section that the EWG dedicates to teflon and its affects on the health of the environment, animals and people.
• The official webpage of DuPont where they assure that the cooking products with Teflon coating- as one can see from the title of the page- that “teflon is safe”. It is an opinion of DuPont.
• An article in the Washington Post about the most likely carcinogenic effects of teflon.
• More information about the composition of the polymer, in Wikipedia.