The environmental documentary "The Devil We Know" mentioned that to produce non-stick pans, a chemical raw material-PFOA, also known as C8, is needed. The book "Dark Waters" with the same theme mentioned that PFOA is very toxic and may cause 6 types of cancer.

Its molecular structure is very strong and basically cannot be degraded. After entering the human body, it may be passed on to the next generation in the blood or body fluids. In other words, the non-stick pan that we are looking for as a kitchen helper may be a "harmful pan" because it contains PFOA. What is the truth? Are non-stick pans really toxic and causing cancer? Does the coating falling off mean that these toxic ingredients have entered the human body with food? Can it still be used after the coating peels off?

Where does the claim that non-stick pans are toxic and cause cancer come from?

During the Manhattan Project, the American 3M Company developed a chemical for making waterproof tank coatings. One end of it is a long-chain fluorocarbon group and the other end is a hydrophilic hydroxyl group. The molecular structure is very strong. .

As a new substance, the toxicity and pollution of PFOA are temporarily unknown, and the cost is extremely low. However, as the Teflon non-stick pans produced by DuPont became popular around the world, scientists discovered the carcinogenicity and toxicity of PFOA, and rumors that non-stick pans are toxic and carcinogenic also became rampant.

Dr. Roy Plunkett accidentally discovered tetrafluoroethylene in an experiment. Subsequently, DuPont registered the "Teflon" trademark and produced Teflon, which uses tetrafluoroethylene as a monomer. A polymer obtained. A French engineer accidentally discovered that using Teflon can prevent fishing lines from knotting while fishing. He thought of the sight of fish sticking to the pan when frying, and speculated that Teflon could also prevent the fishing line from sticking, so he started trial production.

Non-stick pans with Teflon as the main ingredient quickly became popular all over the world as soon as they were released, and are deeply loved by housewives all over the world. However, a test report broke this joy. The supplier published a toxicity report on polytetrafluoroethylene, which concluded that polytetrafluoroethylene caused abnormal development of embryos in white mice! The occurrence of fetal malformations and cancer among DuPont assembly line workers further proves this fact. Subsequently, more than 200 cows died unexpectedly after a farmer used Teflon products. During the investigation, it was discovered that PFOA can cause harm to the human body.

PFOA is a persistent organic pollutant that can exist in the environment for a long time and has a long half-life. It can affect human health and harm the environment through accumulation in the food chain. Its Chinese name is perfluorooctanoic acid, which is mainly used as a dispersant for polymers such as polytetrafluoroethylene. It has extremely strong physiological toxicity, is related to 6 types of cancer, and is also persistent.

DuPont has actually discovered the toxicity of PFOA long ago, but in order to reduce costs, it still uses it as an aqueous solution to make Teflon. It does not assume the corresponding corporate social responsibilities, despises people's lives and health, and also So he went to court. Words such as deformity, cancer and death are shocking. Teflon has also been labeled as "polymer" and "king of plastics". Non-stick pans with Teflon as the main ingredient are toxic and cause cancer, and it has begun to be widely circulated.

Will using non-stick pans cause cancer?

People think that Teflon is poisonous and non-stick pans cause cancer. Is this really true? In this regard, "cctv Life Tips" and Beijing University of Chemical Technology conducted related experiments. The researchers scraped out a part of the Teflon coating in the non-stick pan and put it into a small container for weighing. Subsequently, experts used a thermogravimetric analyzer to detect the decomposition temperature of the coating. After one hour of observation, they concluded that the decomposition temperature of Teflon is approximately 300°C. In short, Teflon only begins to decompose at 300°C.

Professor Xiong Jinping from Beijing University of Chemical Technology said: Teflon will only start to decompose when it reaches its decomposition temperature, and the decomposition products and toxicity will also be different at different temperatures. For further verification, the researchers also poured cooking oil into the non-stick pan to test the temperature inside the pan during heating.

The results show:

When the oil in the pot reaches a suitable cooking state, the temperature inside the pot is about 130°C; when the oil starts to smoke, the temperature inside the pot is about 200°C. ; When the thick oil smoke starts to choke people, the temperature in the pot is 300℃.

However, under normal circumstances, when the oil starts to smoke, we start cooking. At this time, the temperature in the pot is only 200°C, which has not reached the temperature conditions for Teflon to decompose.

So, generally speaking, non-stick pans can be used normally when the temperature inside the pan does not exceed 300°C while avoiding high paste and oily smoke. In fact, Teflon itself is non-toxic and extremely stable. It is not only cold and heat resistant, but also acid and alkali resistant.

At present, the main component of common non-stick pan coatings on the market is still Teflon. The polytetrafluoroethylene (PTFE) needs to be polymerized using a solvent, and then applied to the surface of the pan to fill the unevenness. Bake the uneven areas to form a smooth film.

If you look carefully, you will find that the inner surface of the non-stick pan is very different from that of ordinary iron pans, steel pans, etc. PFOA has been included in the banned list in many countries, but in the process, some unscrupulous merchants will still illegally use PFOA for processing like DuPont. If it is not volatilized, high-temperature cooking will still cause cancer risks.

Therefore, when purchasing non-stick pans, we should choose formal channels and choose non-stick pans that meet national standards in order to fundamentally avoid risks. It should be noted that when a Teflon non-stick pan is dry-heated for 5 minutes, the temperature can reach 800°C and decompose into the toxic gas perfluoroisobutylene, which is harmful to human health. Therefore, avoid dry cooking non-stick pans for a long time.

Can the non-stick pan still be used if the coating comes off?

If the non-stick pan is used for a long time or is bumped frequently, the coating will be scratched and peeled off. Some people are worried that these fallen coatings will cause harm to the human body if eaten, and they wonder whether they can continue to be used.

In this regard, experts said: Teflon is very stable. For regular non-stick pans, even if it falls off and is eaten by humans in small amounts, it will not decompose in the human body and will continue to grow over time. Metabolism is eliminated from the body.

However, once the coating of a non-stick pan falls off, it no longer has the "non-stick" property, and the food will easily burn or stick during the cooking process, which will in turn produce more Harmful substances increase the risk of cancer and are more difficult to clean. Therefore, when the coating of the non-stick pan falls off, it is best to replace it with a new pan to avoid unnecessary trouble.