Misconceptions and Interesting Facts About Teflon

Despite persistent claims to the contrary, Teflon did not emerge as a byproduct of the space program. “Teflon” is a trademark for polytetrafluoroethylene (PTFE), or fluoropolymer resin. Teflon was discovered entirely by accident by Dr. Roy Plunkett in 1938. It was commercially released in 1946.

Polytetrafluoroethylene, or fluoroplastic-4, better known under the trademark “Teflon,” is a polymer of tetrafluoroethylene (PTFE), a plastic with rare physical and chemical properties widely used in engineering and everyday life.

The word “Teflon” is a registered trademark of the American chemical company Chemours, a spin-off of the DuPont corporation.

In April 1938, 27-year-old chemist Roy Plunkett from Kinetic Chemicals was experimenting with gases related to the group of refrigerants (such as Freon) when he discovered that a sample left under cold conditions had turned into a waxy, whitish solid with quite interesting properties overnight. Not only did the material have an unusually slippery surface, but it was also remarkably resistant to almost all chemicals and solvents, including highly corrosive acids.

In 1941, Kinetic Chemicals was granted a patent for Teflon, and in 1949, it became a division of the American company DuPont. The new discovery quickly found practical applications: first in the “Manhattan Project” (the codename for the nuclear weapons program from 1942 to 1946), and then in cookware.

To this day, no one has been able to pinpoint the origin of the “space program” myth—except, perhaps, for the fact that the Apollo space program heavily relied on Teflon, which was used for cable insulation.

Another misconception related to Teflon is the myth that Teflon-coated bullets penetrate body armor much better than any other bullets. In reality, the purpose of the Teflon coating is to reduce wear on the inner surface of the gun barrel, which has nothing to do with the bullet's effectiveness.

Teflon indeed has the lowest coefficient of friction compared to other known solid materials— which is why it works so well as a non-stick coating for frying pans.

But if Teflon is so slippery, how does it stick to the pan? The process requires preliminary sandblasting, which creates numerous tiny scratches on the pan's surface. Liquid Teflon is then sprayed in a thin layer onto these scratches. It is dried under high temperatures, solidifies, and firmly adheres. It is then coated with a special sealant and subjected to another heat treatment.

Next, we will explore in detail the various fields where Teflon is used and how safe it is for our health.

Where else is Teflon used?

Teflon is a white, transparent in thin layers, substance resembling paraffin or polyethylene. It has high heat and frost resistance, remains flexible and elastic at temperatures from −70 to +270 °C, and is an excellent insulating material. Teflon has very low surface tension and adhesion and is not wetted by water, fats, or most organic solvents.

Fluoroplastic is a soft and fluid material, so its use in loaded structures is limited. It has very low adhesion (stickiness). DuPont specifies the melting point for different types of Teflon as ranging from 260 °C to 327 °C.

Teflon is used in the chemical, electrical, and food industries, for the production of membrane clothing, in medicine, in vehicles, for military purposes, mainly as coatings. Fluoropolymers gained the most recognition due to their widespread use in the production of non-stick cookware. So, let's explore the main areas where this unique substance is applied.

1. Food industry and household

Due to its low adhesion, non-wettability, and heat resistance, Teflon, as a non-stick coating, is widely used for making extrusion molds and baking molds, as well as frying pans and pots.

Teflon is also used in the production of other household appliances. A thin film of Teflon coating is applied to razor blades, significantly extending their lifespan and making shaving easier.

Care for Teflon-coated cookware

Teflon coating is not very durable, so when cooking with such utensils, only soft—wooden, plastic, or plastic-coated—utensils (spatulas, ladles, etc.) should be used. Teflon-coated cookware should be washed in warm water with a soft sponge and liquid detergent, avoiding abrasive sponges or cleaning pastes, and should not be overheated above 415 °C or used for high-heat frying.

Interesting history of the Tefal brand

In 1954, French engineer Marc Grégoire discovered a method for applying polytetrafluoroethylene (Teflon) to aluminum. Thus, the first non-stick frying pan was invented. Two years later, in 1956, the company Tefal was founded in Sarcelles, France.

By the end of 1956, the new production was producing 100 pans a day. The invention was marketed under the slogan “The TEFAL pan—the first pan that truly doesn't stick.” By 1961, demand for Tefal pans reached 1 million units per month.

In 1968, Tefal became the leading cookware manufacturer in France, with sales of 49 million francs. That same year, the French household appliance group Groupe SEB struck a deal to acquire Tefal. Throughout its history, SEB has expanded the Tefal product range with new technologies and home appliances.

In 2009, Tefal produced its billionth pan.

2. Industry and technology

In various industries, fibers made from polytetrafluoroethylene (Teflon) have found wide application as high-temperature bag filters, various types of heat-resistant gaskets, threads for textile fabrics, as well as in automotive equipment, general-purpose industrial filters, components of shut-off and control valves, mixers and pumps, filtration and separation equipment.

In aviation, for example, Teflon is used to make flexible metal-plastic pipelines for hydraulic systems operating under high pressure (over 200 kgf/cm²) and with high-temperature working fluid.

Fluoroplastic grade F-4 can be used to make: distillation columns, pumps, pipes, valves, bellows, lining tiles, packing materials. As a dielectric, polytetrafluoroethylene is successfully used in high and ultra-high frequency technology. Rolled fluoroplastic film is used in the production of high-quality cables, wires, capacitors, for insulating coils, and slots in electrical machines. As a structural material, polytetrafluoroethylene is used in the manufacture of various machine parts. Teflon is especially widely used in the production of bearings operating without lubricant, with limited lubricant, and in the presence of a corrosive environment.

Due to its chemical inertness, hydrophobicity (contact angle of 108±2°), oleophobicity, and fluidity, Teflon is widely used for sealing threaded and flanged connections (FUM tape or Teflon tape).

Due to their qualitative characteristics, Teflon self-adhesive tapes are very popular and are often used in the textile and food industries, as well as in everyday human activities. These include: Teflon tape, Teflon tape for vacuum sealers, glass fabric with Teflon coating, Teflon tape for sealers, Teflon self-adhesive tape, and others.

Lubricant

Fluoroplastic-4 (Teflon) is an excellent anti-friction material with the lowest coefficient of sliding friction among known available structural materials (even lower than that of melting ice). Due to its softness and fluidity, solid fluoroplastic sliding bearings are rarely used. In highly loaded units, metal-fluoroplastic bearing liners and metal-fluoroplastic support tapes are used. Such sliding elements can withstand tens of kilograms per square millimeter and consist of a metal base coated with Teflon.

Teflon is also used as an anti-friction filler material (solid lubricant) to improve the sliding properties of base polymers, such as polyetheretherketone (PEEK) or polyphenylene sulfide (PPS), to create a “bearing” composition with high strength, wear resistance, creep resistance, and good anti-friction properties.

Lubricants containing finely dispersed fluoroplastic are known. Their distinguishing feature is that the filler, settling on the rubbing metal surfaces, allows mechanisms to operate for some time even with a completely failed lubrication system, solely due to the anti-friction properties of Teflon.

Electronics

Teflon is widely used in high-frequency technology because, unlike similar materials such as polyethylene or polypropylene, it has a very low temperature-dependent dielectric constant, high breakdown voltage, and extremely low dielectric losses. These properties, along with its heat resistance, make it widely used for wire insulation, especially high-voltage wires, various electrical components, and in the production of high-quality capacitors and printed circuit boards.

In special-purpose electronics, wiring with fluoroplastic insulation, resistant to aggressive environments and high temperatures—wires of the MGTF, MS, and other types—is widely used. A wire with Teflon insulation cannot be melted with a soldering iron. A disadvantage of fluoroplastic is its high cold flow: if a wire with fluoroplastic insulation is kept under mechanical load (for example, by placing furniture on it), the wire may become exposed over time.

3. Medicine

Due to its biological compatibility with the human body, Teflon is successfully used for making implants for cardiovascular and general surgery, dentistry, and ophthalmology. Polytetrafluoroethylene is considered the most suitable material for producing artificial blood vessels and heart pacemakers.

In dentistry, non-resorbable membranes made of Teflon with or without titanium reinforcement are used in guided bone regeneration (GBR) techniques. There is also a suture material made of PTFE.

In 2011, Teflon was first used for plastic surgery of damaged nasal septums and sinus walls instead of titanium mesh. After 12–15 months, the implant completely dissolves and is replaced by the patient's own tissue.

4. Clothing

In the production of modern high-tech clothing, membrane materials based on expanded polytetrafluoroethylene are used.

By physically deforming Teflon, a thin porous film is produced, which is applied to fabrics and used in clothing manufacturing. Depending on the manufacturing process, membrane materials can have either windproof or waterproof properties, while the regulated pore size of the PTFE membrane allows the material to effectively wick away body moisture.

There is a Teflon-based membrane material on a fabric base that allows air to pass through but blocks wind.

Teflon is also used in the production of carpets, umbrellas, raincoats, jackets, balls, and many other items.

5. Other products that use Teflon

• Heating lamps
• Portable heating devices (electric heating pads)
• Iron plates
• Ironing board covers
• Stove burners
• Baking sheets
• Electric grills
• Popcorn makers
• Coffee makers
• Rolling pins (with non-stick coating)
• Bread machines
• Skewer or grill trays
• Ice cream molds
• Toilets with Teflon coating
• Immersion heaters
• Corkscrews
• Stovetop surfaces
• Kitchen utensils
• Pots and pans for frying
• Woks (Chinese pans for frying vegetables and meat)
• Baking molds
• Hot sandwich presses
• Waffle makers
• Optical cryostats
• Razor blades
• Internal tank barrel coatings
• Electrostatic rocket engines
• Seals for articulated mechanisms (joints)
• Paints and varnishes

How Teflon affects the human body

The potential negative impact of polytetrafluoroethylene on human health has been a subject of debate for many years. The polymer itself is very stable and inert under normal conditions. Polytetrafluoroethylene does not react with food, water, or household chemicals.

When ingested, polytetrafluoroethylene is harmless. The World Health Organization asked the International Agency for Research on Cancer to conduct an experiment on rats. The experiment showed that consuming up to 25% polytetrafluoroethylene with food had no effect. This study was conducted in the 1960s and repeated in the 1980s on a common rat population, which consumed PTFE daily in amounts corresponding to 25% of their total food intake.

Research by French experts, published in the journal “60 Millions de Consommateurs,” confirms the safety of non-stick coatings. The French journal reports that tests proved the complete safety of frying pans. All samples successfully passed the test after being rubbed with an abrasive material a thousand times over two cycles.

Teflon is mainly biologically hazardous in two cases: during production and when the finished polymer is overheated (at temperatures above 200 °C).

When fluoroplastic is overheated, thermal decomposition occurs, releasing toxic substances.

Industrial pollution

The main source of biological risks in the production of fluoropolymers is perfluorooctanoic acid (PFOA), known as “C8.” This compound was used in Teflon production in the US since the 1950s. The first information about its health effects was obtained at 3M and DuPont plants in the 1960s. In the 1980s, scientific groups began studying its biological effects. In the late 1990s, US regulatory agencies took notice, leading to the recognition of the substance's danger and the establishment of concentration limits. Technological processes in the US were modified to completely phase out C8. Large-scale campaigns were launched to monitor PFOA concentrations and clarify its impact on human health.

Interesting fact

DuPont faced lawsuits (as depicted in the film “Dark Waters,” 2019) amounting to hundreds of millions of dollars from its own employees and nearby residents due to health damage and the concealment of production hazards. For many years, corporate lawyer Robert Bilott, who uncovered the link between a series of mysterious deaths and a high number of illnesses in a small town and the chemical company DuPont, sued the manufacturer over PFOA contamination of water in the Parkersburg area, where the substance was not regulated by law at the time.

In 2006, DuPont, then the sole US producer of PFOA, agreed to remove the reagent from its plants by 2015. According to the company's official information, since January 2012, DuPont has not used PFOA in the production of cookware and baking molds.

Independent European studies have shown that non-stick coatings do not contain PFOA in amounts exceeding safe limits. The Chinese Academy of Quality Control, Inspection, and Quarantine (GAQSIQ), as well as the Danish Technological Institute, confirm that exposure to PFOA used in cookware production has not been detected.

Thermal decomposition of Teflon

Signs of Teflon decomposition (pyrolysis) are observed at temperatures as low as 200 °C. However, this process occurs relatively slowly up to 420 °C. At temperatures above 380 °C, perfluoroisobutylene (an extremely toxic gas, about 10 times more toxic than phosgene) and other pyrolysis products are released.

Experiments show that the products of thermal decomposition when Teflon is heated above 350 °C cause symptoms of poisoning, resembling metal fume fever—symptoms known as “Teflon flu.”

For more details on such experiments and the potential dangers of overheating Teflon, see the video at the end of this article.

Conclusion

Since the mass release of toxic substances from Teflon begins at temperatures above 450 °C, cookware with non-stick coatings is considered safe, as such temperatures cannot be reached under normal use.

It should be noted that manufacturers consider heating with water or oil in a pan as the norm. Water prevents Teflon from overheating, and its complete evaporation signals significant heating of the cookware, which is no longer visible and can become critical. Cooking oils decompose at temperatures up to 200 °C, releasing smoke, which makes it easier to identify overheating.

Heating a dry pan on a stove is considered abnormal, and in this case, Teflon pyrolysis temperatures are easily reached. To simplify use, some Teflon cookware models are equipped with built-in visual temperature indicators.

In general, use Teflon cookware correctly!

The danger of Teflon decomposition products for birds

The unique structure of birds' respiratory systems makes them highly sensitive to toxic substances in the environment. It has been established that even minimal amounts of perfluorooctanoic acid, when inhaled, affect birds' respiratory systems, leading to death within some time (from a few minutes to several hours).

Small birds are more sensitive to toxic substances; a few seconds of inhaling Teflon vapors are enough for them to die within 24 hours. There are many reports of domestic birds (such as parrots) dying from Teflon pan vapors left unattended and overheated beyond safe temperatures.

Interesting facts about Teflon

Are Teflon pans dangerous?