Introduction to powder coating
Coating powders are mixtures of pigments, resins, curing agents and other additives. They give a corrosion resistant, attractive and durable finish and are used to coat metal window frames, many car components and some 'white goods' such as fridge freezers and washing machines. In more recent years similar techniques have been developed to coat plastics and wood products. In their uncured state these products present health and safety hazards and can also harm the environment.
The basic coating powder process involves it being sprayed through the nozzle of the spray gun where it becomes electrostatically charged. The work-piece to be sprayed is earthed so that the powder particles are attracted to the work-piece and deposited on it. This gives a fairly uniform coating thickness.
The information on the following webpages is separated out depending on who you are, and what information you require.
See also HSE's webpages on occupational asthma Asthma caused by work which gives general advice on the health risks and the control measures needed to reduce the exposures of individuals to asthmagens.
Working with coating powders – employees
The Working with coating powders - employees page is aimed at operators of spraying equipment giving them basic information about the potential risks of using coating powders and what they can do to ensure they use the equipment properly and hence reduce dust exposure. It explains what else can be done (eg washing before eating and reporting health issues), and what personal protective equipment (PPE) should be used.
Reducing risks associated with using coating powders – employers
The Reducing risks associated with using coating powders - employers page outlines the precautions that are required of employers who operate both manual and automatic spraying equipment.
The Specialist powders page gives information on some powders which have historically given cause for concern because some of the constituent chemicals are toxic. These include chemicals such as triglycidyl isocyanurate (TGIC), tri-mellitic anhydride (TMA) and lead chromate based pigments. There may still be some old stock in industry which could still be used occasionally, but it is proposed that under the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) legislation that these chemicals will most probably be prohibited from use in the next few years.
Other Risks when using powder coatings:
- Fire or explosion - minimise the risk by regular cleaning to prevent build-up of dust and exclude sources of ignition, such as naked flames, cigarettes, etc from powder coating work areas. Anti-static footwear, overalls and other personal protective equipment (PPE) should be made from conductive materials. See HSE's Fire and explosion webpages for more information
- Electric shock - minimise the risk by ensuring good earthing of work equipment and regular maintenance of electrical equipment. See HSE's Electricity webpages for more information
- Manual handling risks – lifting and handling of workpieces and the powder coating storage boxes containing the powder. See HSE's Musculoskeletal disorders webpages
- Risks from the operation of pressure systems (ie compressed air systems) associated with powder coating equipment HSG39 guidance book - Compressed air safety for more information