Different types of plastics have drastically different melting points, which means some plastics such as polyvinyl chloride plastics can melt at as low as 165 degrees Fahrenheit, while other types such as the plastic in Teflon cookware will not melt until they reach temperatures of around 600 degrees or hotter. Most sturdy plastics will melt before 500 degrees.
Plastics are polymers that have a huge variety of chemical makeups. For this reason, some plastics are incredibly easy to melt, while others are almost impossible. Sturdy plastics can typically hold boiling water, which is at 212 degrees Fahrenheit, while soft plastics like plastic bags would melt if they came into contact with boiling water.