Illustration: Lu Ting/GT

 "I am not sure what it is made of. It feels like plastic, but it is not labeled as plastic. We bought it from online shops."

Shanghai Television Station recently reported that thin straw sheets used to prepare steamed breads and other steamed snacks have been replaced by "plastic-like" sheets at many local shops. Workers at these shops generally say the sheets are made of food-safe, nonstick silicone. Such claims were questioned after Internet users noticed that similar sheets were being sold online for as little as 2 yuan ($0.33), shipping included. Material science experts say that if these items were made with genuine silicone, they would likely be much more expensive. Cheaper materials, such as PVC, could lead to human health problems if used to prepare steamed foods. Many have called for relevant authorities to look into the quality of these new sheets.