Flame Retardant

Flame Retardant

Flame retardants are chemicals used in thermoplastics, thermosets, textiles and coatings that inhibit or resist the spread of fire. These can be separated into several different classes of chemicals:

• Minerals such as aluminium hydroxide ATH, magnesium hydroxide MDH, huntite and hydromagnesite, various hydrates, red phosphorus, and boron compounds, mostly borates.
• Organohalogen Compounds. These include organochlorines such as, chlorendic acid derivatives and chlorinated paraffins; organobromines such as decabromodiphenyl ether (decaBDE), decabromodiphenyl ethane (a replacement for decaBDE), polymeric brominated compounds such as brominated polystyrenes, brominated carbonate oligomers (BCOs), brominated epoxy oligomers (BEOs), tetrabromophthalic anyhydride, tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD). Most but not all halogenated flame retardants are used in conjunction with a synergist to enhance their efficiency. Antimony trioxide is widely used but other forms of antimony such as the pentoxide and sodium antimonate are also used.
• Organophosphorus compounds such as organophosphates, tris(2,3-dibromopropyl) phosphate, TPP, RDP, BPADP, tri-o-cresyl phosphate, phosphonates such as DMMP and phosphinates. There is also an important class of flame retardants that contain both phosphorus and halogen, examples of such are the chlorophosphates like TMCP and TDCP.

Mineral flame retardants are typically additive while organohalogen and organophosphorus can be either reactive or additive. The basic mechanisms of flame retardancy vary depending on the specific flame retardant and the substrate. Additive and reactive flame-retardant chemicals can function in the vapor or condensed phase.

The annual consumption of flame retardants is currently over 1.5 million tonnes per year, which is the equivalent of a sales volume of approx. 1.9 billion Euro (2.4 billion US-$).