3.1 Zinc oxide is an important rubber compounding material. It is used to activate the organic accelerators to increase the rate of vulcanization and to enhance physical properties. It is also a vulcanizing agent for halogen-containing elastomers.

1.1 This classification system covers the compounding material commercially known as zinc oxide. The types of zinc oxide used in the rubber industry are related to the production process used. Typical chemical and physical properties are included.