Polyester resins are combustible. There are no non-flammable resins, but polyester resins can be formulated with limited flammability or self-extinguishing properties — meaning that, once cured, they stop burning once the ignition source is removed.
Self-extinguishing properties can be achieved through various methods. M.M. uses aluminium hydroxide as a flame retardant, which decomposes at around 180°C, absorbing a considerable amount of heat in the process and releasing water vapour. In addition to acting as a fire retardant, it is highly effective as a smoke suppressant. No halogens are used.
M.M.’s IFR gratings are classified as Bfl-s1 in accordance with EN 13501-1.
IFR gratings have also been assessed for the dripping parameter, which describes the release of molten droplets of the product or the production of burning particles during and after combustion, and are classified as level d0 — meaning no dripping.
