10/10/2019 - 10 min
How Do Flame Retardant Adhesives Work?

As fire safety regulations increase, more manufacturers turn toward using flame retardant materials in their product assembly processes, including adhesives. Be sure you’re in the know on what these materials are and how flame retardant adhesives work to know if they’re right for your application.
What are Flame Retardant Materials?
Flame retardants, projected to reach $12.81 billion by 2021, stem from various raw materials, such as:
- Bromine
- Chlorine
- Phosphorous
- Zinc
These raw materials are then processed according to application requirements of end-use industries, include:
- Automotive and transportation
- Electronics and appliances
- Building and construction
Once formulated into adhesives, these materials are able to:
- Prevent ignition
- Reduce the rate of flame spread if ignited
- Reduce the fire intensity

How Do Flame Retardant Adhesives Work?
Flame retardant adhesives offer four modes of action to mitigate the fire, depending on its formulation. These include:
- Gas Phase: When the material reaches its decomposition temperature, free-radical reactions are rapidly dispersed, which interrupts the combustion process.
- Condensed Phase: The material forms a char layer, which creates a barrier between the heat and fuel sources.
- Endothermic Cooling: Water is released from hydrated metal, which cools the reaction.
- Intumescence: Flame retardant materials that follow this mode of action are composed of a carbon donor, blowing agent and acid donor. When activated, they cause a thick, foaming layer of char to form.
Bostik formulates a variety of flame retardant adhesives designed to improve end-use application safety while enhancing operational efficiencies. Contact a Bostik expert today to learn more about how these solutions can help you.