Zinc Borate is an important additive to help achieve excellent flame resistance in rubber articles. It is a free-flowing powder that disperses easily. Zinc borate can be added to any flame retardant system and will improve flame test results with minimal effect on compound properties. Zinc borate will form a glassy char at high temperatures that prevents flame propagation. It also releases water of hydration similar to ATH. Zinc borate is a synergist with antimony oxide and halogenated flame-retardants as well as ATH. The combined ingredients will have better flame resistance than the separate materials would have. Zinc borate helps in compounding halogen-free, flame-resistant rubber that generates minimum acidic smoke.