HMG Knowledge Base
Hazards & Preventative Methods of Paint Spraying
When dealing with paint, potential hazards exist regarding:
- Fire and explosion - Due to content of solvent & oxidising materials
- Intoxication of operator - Due to contact with high levels of toxic compounds
Unfortunately, some serious accidents have happened due to the use, or more commonly the mis -use of paint products. Fire and explosions have caused damage to property as well as causing death. Prolonged exposure to harmful substances due to not using personal protection equipment has caused acute and even chronic harm to paint users. The following principles of safety give a guideline on preventative measures, when carrying out paint spraying.
When attempting to reduce the levels of risk and understand those risks, some points should be kept in mind: Flammability:
- Flash point - The lowest temperature ( ºC ) at which the solvents in a product give off sufficient vapour to form ignitable mixtures with the air above the surface.
- Explosion limits - The limits ( % by volume ) giving the range of flammable vapour concentration in which fire and explosion can occur upon ignition.
Inherently, if the flammable vapour concentration is within the explosion limits (also known as flammability limits), a product will catch fire easier than one with a higher flash point.
- Threshold limit value ( TLV ) - Refers to the airborne concentration ( parts per million or mg per m³ in air ) of substances that represent conditions under which it is believed that nearly all workers will be repeatedly exposed without adverse effects. The lower the TLV, the higher the toxicity of a substance. TLV regulations are generally available from local or central government.
Fire and Explosion
The key factors in preventing fires and explosions are:
- Adequate ventilation
- Elimination of ignition sources
To avoid fires and explosions:
- The flammable vapour concentration must be maintained below the lower explosion limit. Ventilation requirements are available from local or central government.
- Constant air intake to the spray booth/room must be maintained
- Adequate airflow into the spray booth/room must be obtained to avoid a vacuum being formed within the booth/room
Elimination of Ignition Sources
When paint is or has been sprayed in a confined area, the likelihood of fires and explosions occurring can be minimised by adhering to the following precautions:
- Smoking must be permitted only in designated locations
- Welding, cutting or metal grinding must be forbidden until solvent vapours have been totally removed
- Spark-proof/Explosion-proof electrical equipment and certified lighting must be used within paint application areas. Airless spray equipment must be earthed to avoid static electricity discharge
- Paint must only be applied to cold surfaces. Heated objects of welding must be at ambient temperature before any paint is applied
- All clothing, shoes, safety equipment, tools etc must be manufactured from spark proof materials
- Overspray, particularly on booth filters, should never be allowed to build up. This is a static hazard
Operational Health Hazards
All persons required to work in areas where there is a risk that their clothing may be sprayed or splashed with paint should be furnished with protective clothing such as:
- Disposable paper suits
- Disposable gauntlets
- Impervious gloves
- Face masks
Additional use of barrier cream should be encouraged. Good safety habits should be established with respirators. They should be inspected and cleaned on a regular basis and expertly repaired as necessary, using only manufacturers replacement parts. It is good practice to start each working day by cleaning personal respirators. Air-fed respirators should have air supply checked frequently for hose damage, air contamination and suitability of compressor air intake. High standards of housekeeping should be operated at all times ensuring containers are covered, spills are contained, rags removed and overspray is effectively cleaned up.