Zeal developed their own silicone material 7 years ago which is odorless. Silicone before always had a chemical smell to it and most cheap silicones still do now. Zeal silicone is EEC approved which is a far higher standard for food contact than the FDA requirement for quality of silicone. In fact, FDA silicone quality would not pass an EEC food contact test. The real problem for silicone is when it comes into contact with hot oils and other hot substances. Inferior silicone will leach into food. Zeal silicone does not and it also stands up to high temperatures of food contact [up to 572 F/ 300 C]. Throw out your old bulky, hard to clean metal muffin pans with these easy to clean, space-efficient Silicone Muffin Cups. Constructed from commercial grade silicone, this silicone bakeware promotes even heat distribution and quick and even cooling and can be filled with muffin or cupcake batter, placed in the freezer, then thawed in the microwave. Safe at temperatures as high as 572F, these flexible silicone muffin cups make removing cupcakes and muffins from the pan a snap by simply pressing on the bottom of each muffin cup. These silicone muffin cups make standard 3" muffins or cupcakes. They are constructed from safe and durable commercial grade silicone with no bulk fillers, are easy to clean and dishwasher safe. Promotes even heat distribution and shorter bake times, conserving energy. This silicone bakeware set includes six standard muffin cups.