Composite material

Materials science

Fire retardant

Environmental science

Nature Reviews Materials

Flame retardants mitigate the threat of fire from inherently flammable materials responsible for sustaining a high standard of living. Although bulk flame retardants have proven effective for many years, there is now increased interest in the use of surface treatments to localize flame-retardant chemistry at the exterior of a material, where combustion occurs, in an effort to preserve desirable bulk properties and minimize the amount of additive needed. This Review provides a historical overview that leads to the most promising surface treatments that will help pave the way for developing more effective and non-intrusive flame retardants in the future. The way in which a fire transpires, and the various chemistries and mechanisms used to counteract fire propagation, are discussed. Challenges that remain to improve current flame-retardant surface treatments are also addressed, as the success of these treatments depends on the scalability, durability and ability to impart desired functionality without conferring environmental problems. Fire endangers lives and property worldwide. Significant efforts are underway to develop flame-retardant surface treatments that minimize the weight added to a given object and preserve its intrinsic mechanical properties. This review summarizes the history and latest developments in flame-retardant treatments, as well as outlining the challenges ahead.

Flame-retardant surface treatments