1. You can check whether the tin foil tray has anti-counterfeiting marks. The real tin foil tray has anti-counterfeiting code on it, but the fake tin foil tray doesn't.
2. From the way of tapping the tinfoil paper with metal to listen to the sound, the crisp sound is true and the heavy sound is false.
For how to judge whether the tin foil tray is food grade, it is suggested to consult the relevant food industry practitioners to obtain more accurate information.