1. Stabilizers One of the most critical functions of additives in plastics is to protect the material from degradation due to exposure to environmental factors, such as heat, light, and oxygen. Stabilizers, such as antioxidants, UV stabilizers, and thermal stabilizers, are incorporated into plastic formulations to extend their lifespan. For example, ultraviolet (UV) stabilizers prevent discoloration and brittleness that can occur when plastics are exposed to sunlight.