How to reduce exposure of workers to hazards in powder coating

How to reduce exposure of workers to hazards when you use powder coating powder 

Elimination

Choose TGIC-free powder coating powder which are readily available.

Engineering controls

The most effective engineering controls for reducing worker exposure are booths, local exhaust ventilation and automation of the powder coating process. In particular:

• application of powder coatings should be performed in a booth where practicable
• local exhaust ventilation should be used when conducting powder coating activities, during filling of hoppers, when reclaiming powder and during clean-up
• use automatic spray guns, feed lines and feed equipment
• prevent unnecessary powder build-up inside powder coating booths by minimising spray gun air pressure to prevent overspray
• interlock the power supply and powder coating feed lines with the air extraction system so that if a fault develops in the ventilation system, the powder coating and power supplies are cut off
• prevent or minimise the generation of dusts by containing the opening of powder coating packages, loading of hoppers and reclaiming of powder, and
• minimise the generation of dust when filling the hopper by considering the layout of the work station and the size of the hopper opening.

The following should be considered regarding the use of hoppers:

• use spray systems where the container in which the TGIC is supplied can be used as the hopper, thereby avoiding the need to transfer powder
• large hoppers can be used to avoid frequent refilling of smaller units
• powder coating powder that are supplied in drums allow for the powder to be transferred mechanically rather than manually

Administrative controls

Administrative controls should be used to support other measures in order to reduce exposure of workers to hazards associated with powder coating activities. Administrative controls include:

• work practices designed to avoid the generation of dust
• restricting access to spray areas
• ensuring workers are never between the object to be sprayed and the airflow of contaminated air
• situating the articles to be sprayed sufficiently within the booth to avoid rebound
• ensuring that only spray guns and the cables connected to it are in spray areas or booths. All other electrical equipment should be located outside the booth or area or enclosed in a separate fire-resistant structure, unless the equipment is suitably designed for a hazardous area – for example it may be installed in accordance with AS/NZS 60079.14: Explosive atmospheres – Electrical installations design, selection and erection or AS/NZS 3000: Electrical installations. This equipment should be protected against the depositing of paint residues
•  implementing good personal hygiene practices, for example powder coating dust should not be allowed to collect on the face, exposed body areas should be thoroughly washed and overalls should be regularly cleaned storing powder coating and waste powder in a designated area with restricted access
• cleaning booths and surrounding areas on a regular basis
• promptly cleaning-up spills of powder coatings to reduce the spread of TGIC
• using a vacuum cleaner with a High Efficiency Particulate Air (HEPA) filter for clean-up operations and not using compressed-air or dry sweeping
• vacuuming work clothing as an initial method of decontamination
• emptying vacuum cleaners in the booth and under exhaust ventilation
• taking care to avoid the generation of dust during disposal of waste powder
• baking waste powder in the original box for disposal to landfill as a solid
•  ensuring all electrical equipment is switched off before cleaning spray guns
• keeping the quantity of hazardous chemical to a minimum at the workplace
• cleaning spray guns with a solvent that has a high flash point and, have low vapour pressure at the ambient temperature
• ensuring that incompatible chemicals are not stored together e.g. flammable and oxidising
• regularly checking that plant and equipment are being cleaned and maintained including ventilation and spray equipment and filters, and
• proper induction training and general training of workers.