How to reduce thermal spray hazard

Thermal spray processes put strong coatings onto metal parts. A powder or wire is melted and then sprayed at high speed onto a surface and this creates a tough layer but it also makes a lot of very fine dust and fumes. These tiny particles can spread through the work area and be breathed in without people even realising it.

Why the Dust Is a Problem

The main risk comes from breathing in metal dust. It can also get into the eyes, land on the skin or be swallowed if your hands aren’t washed properly. In many thermal spray coating processes, like the examples seen here, www.poeton.co.uk/surface-treatments/thermal-metal-sprays/, the dust may contain metals such as nickel, cobalt, copper, aluminium and chromium.

Nickel can cause skin allergies and has been linked to cancer and cobalt may lead to skin rashes and breathing problems. Copper can irritate the eyes and lungs and breathing in aluminium dust for a long time can affect the lungs. Hexavalent chromium, which can form when spraying chromium materials, is especially dangerous and is linked to lung cancer and serious damage to the nose, throat, and lungs.

How to Reduce the Hazards

The best way to lower the risk is to control the dust at its source so a dust collection system designed for your specific spraying process is essential. Local exhaust ventilation should capture fumes as they are created, not after they spread. Air testing should be carried out to check that metal levels are below legal limits and workers should wear proper respiratory protection, eye protection and gloves.