Heat Stabilizer is used to prevent degradation (yellowing) and plastic scorching at high temperatures. The correct amount of heat stabilizer is in all of our M-F Plastic formulations. Hard plastics that are kept at high temps longer will need to be stabilized. Very little additional stabilizer needs to be added: use a maximum of 4 fl oz of stabilizer for every 5 gallons of plastic. Heat Stabilizer comes in pint container.