The most important inorganic flame retardants are aluminum trihydrate (ATH) and magnesium hydroxide (MDH) used as filler in wide plastic and rubber applications.
In addition, antimony trioxide (ATO) is used in large quantities as a synergist with halogenated flame retardants and PVC. Aluminum oxide hydrate (AlOOH or Boehmite) also acts as a synergist in conjunction with metal phosphinates.
Aluminum Hydroxide(also known as ATH)decomposes at around 200 °C. So it only can be used with plastics processed at lower temperatures such as PVC, polyethylene, EVA, and thermosetting.
Aluminum oxide hydrate (AlooH) or Boehmite decomposes at 320 °C. It can therefore be used in engineering thermoplastics and is synergistic with metal phosphinates. It is also used in printed circuit boards.
Magnesium hydroxide (MDH) decomposes at around 300 °C. Its main applications are polypropylene, polyamides and wire & cable.