Powder coating is a dry powder application that is an alternative to liquid paint. This versatile finishing method is continuing to grow in popularity because it offers high performance strength and resilience.
Its main application is in the finishing of metals, giving them protection from corrosion and making them durable for extended outdoor exposure and use.
It also protects metal furniture and various household items, along with machinery and fabrications.
But, given its broad range of uses, how safe is it? Is powder coating flammable?
Unlike liquid paints, powder coatings contain no volatile organic compounds (VOCS) such as solvents.
Volatile organic compounds are organic materials which, at ordinary room temperature, have a high vapour pressure.
What this means, is that, at a low boiling point, VOCs will release large numbers of molecules to evaporate into the surrounding air. VOCs in liquid form may also sublimate from liquid or solid form to release molecules into the air.
This is why they are volatile.
Because powder coating contains no VOCs, if it burns, any fumes will be of a low toxicity, and the material will generate a low density of smoke.
However, generally coatings used in applications such as architecture and construction have both a high electrical and thermal resistance.
This means that the metal surfaces they coat retain their fire resistance.
The main risks associated with the flammability of powder coating come from the possibility of dust explosion and fire hazards.
These can arise from combining air with combustible organic powders.
However, thermosetting powders are only hazardous within certain concentrations of powder and air mixtures.
If you follow proper health and safety procedures, these concentrations should only occur within the spraying and recovery system you are using to apply powder coatings.
This should minimise the risk when powder coating is most flammable.
Overall, powder coatings are non-flammable, but in their atomised state, during spray application, this is when they could support fire.
During the curing process, applied powders are subjected to temperatures of 200°C to cure them.
Once finished, powder coatings offer a high resistance to heat, with some specially formulated coatings having the capability to withstand temperatures of up to 550°C.
Powder coatings are generally safe form fire hazard, providing you follow careful procedures during the spraying process.
If the end application of the powder coating requires fire resistance, then it is important that the coated surface will meet regulatory standards.
These include BS 476 and EN 13501-1.
For more information about powder coating, its performance and potential applications, please contact us.