Plastic additives are chemicals added in a polymer to modify its properties. The polymers used in plastics are combined with monomeric units and are not in their pure form, but are harmless. The objective is to improve the processing characteristics and properties of plastics and to enhance performance. These monomers are known as plastic additives and can be classified as reinforcing fibres, coupling agents, stabilizers, colorants, fillers, processing aids, flame retardants, peroxides and antistatic agents. Plastic additives enable safe handling of the plastic during the manufacture of finished products. The stabilizing plastic additives are halogen stabilizers, ultraviolet absorbers, antioxidants and biological preservatives. Also, there are processing aids such as lubricants and flow controls.