Flame testing to check to see if a toy is silicone has been mentioned several times, but do note that this can be very dangerous. Many non-silicone sex toy materials are quite flammable and easy to light on fire. TPR burns very easily and melts at a low temperature - this means that there may be a burning liquid from your sex toy that can drip flames, seriously burn you, and will float on water (so don't toss a cup of water at it to put it out). If you feel the need to flame-test your toys please do it in a fireproof area where burning liquid will not run somewhere that can cause a fire or burn anyone. If you need to put it out treat it like a grease fire, and cover with a non-burnable metal cover until it goes out. Eden does a very good job of pinning down what the toys are made of in almost all cases, so there really isn't much of a need for personal flame tests.