The inventors of Teflon, the wondrous material that is ‘non-stick’ and the most widely used, made many people’s lives easier —- no sticking means easier cooking, less use of oil, and no soaking and scrubbing pots and pans. Dosas, omelettes, curries, and just about any food can take advantage of being cooked in a non-stick vessel.
However, there has been an ongoing debate over non-stick surfaces releasing toxic substances during the cooking process. A synthetic chemical called perfluorooctanoic acid, known as PFOA, is used in the manufacture of non-stick pans. When the vessels are heated, the coating can break apart and release these toxic chemicals. The point is still being debated. The important thing to note is the temperature at which this damage begins. A test published by the Environmental Working Group (EWG), an independent consumer watchdog, shows that a Teflon, even on heavy-bottomed pans, can easily be heated to above 382°C in five minutes during the normal process of pre-heating.
So how hot should be the tawa when you are making dosas, for example? The directions for all non-stick recipes mention medium heat, which is approximately 204°C. I measured 180°C on a good quality tawa used to make dosas. It was heated for 2 minutes which is sufficient pre-heating to make dosas. The heat is reduced and controlled after this point and appears to be safe as far as heat conduction is concerned. It is up to you to control the heat.
Consensus Most researchers agree that using non-stick utensils for cooking is safe if temperatures are less than 232- 260°C. At very high temperatures, pans significantly decompose, emitting strong chemical fumes. These pans would not have been in the market if heating to such high temperatures were commonplace. The more older and scratched the non-stick coating gets, the more harmful it is, because the surface is more vulnerable to erosion and particle emission. In Indian households, many a time these pans are not handled with care and scratch easily during the cooking and cleaning process. Employed cooks need to cook quickly to get to the next household, so they generally use high heat for faster cooking. The non-stick pan deteriorates with every use with such high heat. One solution is to only use non-stick pans when you cook and control heat.
When using non-stick, keep these tips in mind: Use good quality, heavy-bottomed cookware. It will sustain higher temperatures. If the bottom is too thin, then it gets heated too fast. Good quality is more expensive, but it is a must if you want to use a non-stick.
Do not use metal spatulas or spoons — they scratch the surface.
Clean with mild detergents and a soft scrubber.
Do not use scouring pads.
Do not leave pan on a high flame. If you are making dosas or chapatis, you need to make sure the pan is not left on high heat at all times.
Learn how to control the heat. Most cooking should be done on medium to low heat in any case. When the surface begins to scratch or chip, it is time to get a new vessel.