CSLB C-33 Painting & DecoratingSafetyMedium
A painting contractor is using a spray application method for oil-based paints in a large commercial building. To prevent the accumulation of flammable vapors, which type of ventilation system is generally most effective?
- APortable fan directed at the worker
- BLocal exhaust ventilation (LEV) system
- CRecirculating air filtration system
- DGeneral dilution ventilation system
Show answer & explanationAnswer & explanation
Correct answer: D. General dilution ventilation system
General dilution ventilation is designed to dilute and remove airborne contaminants from the entire work area, making it effective for controlling flammable vapor accumulation in large spaces during spray painting.
Why the other options are wrong
- A. A portable fan directed at the worker may disperse vapors but does not effectively remove them from the space and can increase exposure.
- B. LEV is highly effective for specific point sources but less so for area-wide spray operations.
- C. Recirculating systems typically filter particulates, not volatile organic compounds (VOCs) or flammable vapors.
General Dilution Ventilation
A ventilation method that introduces fresh air to dilute and exhaust contaminated air from an entire work area, reducing the concentration of airborne hazardous substances.
- Effective for low toxicity or low flammability contaminants.
- Requires large volumes of air movement.
- Less effective for highly toxic substances or localized high concentrations.
Memory trick: Ventilation Varies Vapors Vigorously.