This type of fibre is intended for low flammability and fire prevention. While a "normal" polyester fibre melts at around 255°C and has an LOI (Limiting Oxygen Index) of approximately 21, modacrylic fibres do not melt at all but disintegrate at 170°C. The LOI is around 28 and above. This aspect is a major factor due to injury risks, for example, in public facilities, aircraft, railways etc.