What is the problem?
Spray painting results in exposure to hazardous substances including:
- Paints
- polyisocyanates
- solvents
- degreasers
- powders
- paint removers
- Dusts
- glues
- lacquers
- surface preparation products
- Resins
- rust converters / removers.
Other hazards include:
- plant
- electricity
- paint injection
- noise
- airless spray guns
- manual handling
- risk of fire and explosion.
Health effects can include:
- occupational asthma
- allergic dermatitis
- lung cancer
- painter’s syndrome or solvent neurotoxicity (from long-term exposure to organic solvents and affects the brain)
- damage to the reproductive systems, kidney and liver.
Short-term effects can include:
- irritant contact dermatitis
- burns to the skin and eyes
- vomiting and diarrhoea
- irritation to nose, throat, lungs
- headache, dizziness, nausea and fatigue.
Problem assessment
Risk assessment involves working out the level of risk from each hazard in the spray-painting process: how long is the person exposed? how great is the exposure? what harm might occur and how severe could it be?
Control measures
Spray Booth
Spray-painting must be carried out in a spray booth unless, because of its shape, size or weight, it is impractical to do so; for infrequent spraying of heavy or bulky equipment; or minor operations such as spotting or touching up. The spray-booth must be designed, constructed, installed and maintained in accordance with AS/ NZS 4114.1:2003 Design, construction and testing of spray-booths; and AS/NZS 4114.2:2003 Selection, installation and maintenance of spray-booths.
Exclusion zone/confined space
A spray-painting exclusion zone should be established according to AS/NZS 2430.3.9 1997: Classification of hazardous area: Part 1: flammable gas and vapour atmospheres. Spray-painting in a confined space must be carried out as per AS 2865: 2001 Safe working in a confined space.
Spray booth/mixing room ventilation
The ventilation system should provide an optimum, continuous, uniform and evenly distributed supply of airflow throughout the spray-painting area and mixing room to the exhaust outlets and eliminate pockets of still air in the booth. Where spray-painting is carried out in a building or structure other than a spray booth or confined space, it should be of open construction or a mechanical exhaust system should be used to prevent the build up of flammable or toxic fumes.
Spray-painting guns
High-volume-low-pressure (HVLP) spray guns are recommended over conventional gravity or siphon-feed guns because HVLP guns cut paint over-spray concentrations in half. HVLP guns transfer paint more efficiently and can reduce paint usage.
Respiratory protection
Even the best precautions do not completely eliminate overspray from the air workers breathe. Personal respiratory protective equipment is also recommended.
References
NZS/AS 1715:1994 and AS/ NZS 1716:2003 Selection, use and maintenance of respiratory protective devices, and
NZS/AS 1716:1991 Respiratory protective devices). The current Spray coating Regulations date back to 1962 and are being revised.
