Melamine cyanurate is a halogen free flame retardant. It is the salt of melamine and cyanuric acid which has a higher thermal stability than pure melamine. Therefore, melamine cyanurate is often used in polymers with high processing temperatures. Above 320 °C it undergoes endothermic decomposition which dilutes the oxygen available to sustain combustion. At the same time the liberated cyanuric acid reacts with the polymer to form an insulating char. Melamine cyanurate is used in nitrogen based polymers such as polyamide, thermoplastic polyurethane and polyurethane.