Are Anodised Metals Safe in Fires?

Fire safety is a critical element of UK Building Regulations. When designing large façades, coatings may not immediately seem like a priority, but their behaviour in fire conditions is important to consider.

The horrific fire at Grenfell Tower resulted in much stricter standards, although it may be several years before the inquiry’s recommendations are fully implemented.

Anodising

Anodised aluminium is widely regarded as one of the safest finishes. The anodising process simply thickens the naturally occurring oxide layer on aluminium through electrolysis. Aluminium itself carries an A1 fire rating, meaning it is fully non-combustible, so anodised coatings are also classified as A1. In other words, anodised finishes pose no fire risk.

Electroless Nickel Plating

This is a popular alternative to anodising. It is a complex process provided by specialists like https://www.poeton.co.uk/surface-treatments/plating/electroless-nickel-plating/. Electroless nickel plating provides superior hardness and chemical resistance, although it adds weight and thickness, but its thermal stability means it does not burn.

Powder Coating

Powder coatings behave differently. Although only a very thin film, typically 40-60 microns, they contain organic compounds that can ignite under extreme conditions. This places them at an A2 fire rating. While this still offers a high level of fire resistance, it is not technically non-combustible. Nevertheless, building control officers may approve powder-coated façades, especially if additional testing demonstrates A1 behaviour in certain thicknesses or colours.

Where thicker layers are required for corrosion resistance-such as in coastal environments-anodising and nickel plating may be more reliable solutions. Ultimately, early consultation with fire officers and façade specialists is essential to ensure regulatory compliance and peace of mind.