The BobbStopper is mostly composed of food-safe components. The alligator clip, the weight, and the fishing line were specifically chosen because they are made of materials that are safe to submerge in liquids meant to be consumed. The alligator clip and weight are made of stainless steel (the same material as many of Gregory's pots) and the string is a nylon fishing wire. We are still testing to see how food-safe the bobber is. We are also still testing to figure out the highest temperature of liquid that the BobbStopper can safely be used in. We advise using tongs when removing the device from hot liquids in order to reduce to risk of accidents.