OccuSafe Industrial Hygiene Consulting

OCCUSAFE UPDATE
Monthly Round Up of Important Ideas and Standards in
Industrial Hygiene and Safety

April 2015

IN THIS ISSUE: Chemical Exposure Hazards in Spray Painting Operations

Spray painting is the process in which a liquid coating, usually paint, is changed into a mist or aerosol in order to apply it to a surface. Most spray painting is performed with the use of a spray gun, which helps reduce the coating to a fine spray. In a factory setting, spraying operations are typically done in a spray booth. These are partial or full enclosures that can be equipped with mechanical ventilation and a fire suppression system.

Paint is a mixture of solvents, pigments, and additives that form aerosols, mists, and vapors during spray operations. Potential health hazards include exposure to solid and liquid aerosols as well as organic solvent vapors. The most common means of exposure is through inhalation or dermal adsorption of paint components. Short-term health effects of the solvents are respiratory tract irritation, shortness of breath, dizziness, influenza-like symptoms, tightness of the chest, nausea and headaches. Long-term effects can include cancer, sensitization of respiratory systems, asthma, abnormal reduction in lung function, emphysema and central nervous system dysfunction. Some painting additives and pigments contain highly toxic materials such as hexamethylene diisocyanate (HDI) and toxic metals, which can have additional effects.

Methods to control the harmful effects of spray paints:

• Keep a thorough inventory of all paint components. Safety Data Sheets, manufacturer literature, and other information should be reviewed. Testing may be needed to measure concentrations of each hazardous material and the exposure to the painters.
• Maintain the spray booth. Daily checks should be made to see that filter pads are not blocked. A manometer can be installed to measure the static pressure caused by build-up on the pads. Recorded maintenance checks of the belts, motor, and other mechanical parts of the booth should be instituted.
• Mix paints carefully. Mixing paints can also expose the operator. These tasks should be done in a well-ventilated area or an enclosure similar to a paint spray booth.
• Personal protective equipment, such as a Tyvek-type suits and gloves should be worn to reduce skin exposure and contamination of other parts of the facility. Where paints contain hazardous metals such as Hexavalent Chromium personal protective equipment should remain in the painting area and never taken into restrooms and break room.
• Work practices are very important. The amount of exposure can vary greatly between operators. Painters should never place themselves between the work and the ventilation exhaust. Turntables, trolleys, hangars, and other devices can be used to place the part so paint does not pass through the employee’s breathing zone.
• Select appropriate respiratory protection. This will depend upon the hazards of the paints, characteristics of components of the paint, and the concentration. Operators should be medically evaluated before issued any type of respirator.
• Additional hazards: Support operations such as sanding and cleaning parts before painting can present additional hazards. Dusts may contain hazardous metals that can present additional health hazards.