CSLB C-33 Painting & DecoratingSafetyMedium
A painting crew is applying a highly flammable solvent-based sealant inside a newly constructed, unventilated room. What is the most effective fire prevention strategy to implement in this scenario, beyond simply eliminating ignition sources?
- AEstablishing a hot work permit system
- BImplementing continuous mechanical ventilation to dilute vapors
- CHaving fire extinguishers readily available
- DEnsuring all workers wear flame-retardant clothing
Show answer & explanationAnswer & explanation
Correct answer: B. Implementing continuous mechanical ventilation to dilute vapors
In an enclosed space with highly flammable solvent-based materials, continuous mechanical ventilation is crucial to dilute flammable vapors below their Lower Explosive Limit (LEL), thereby preventing the formation of an ignitable atmosphere. This goes beyond simply removing ignition sources.
Why the other options are wrong
- A. A hot work permit system addresses ignition sources, but the question asks for a strategy beyond just eliminating ignition sources, focusing on vapor control.
- C. Fire extinguishers are for fire suppression, not prevention of an explosive atmosphere.
- D. Flame-retardant clothing protects workers in case of a fire, but does not prevent the fire or explosion itself.
Flammable Vapor Dilution
The process of reducing the concentration of flammable vapors in an enclosed space through ventilation to prevent them from reaching their Lower Explosive Limit (LEL).
- Crucial for fire and explosion prevention.
- Achieved primarily through mechanical ventilation.
- Must be continuous and adequate for the space and material.
Memory trick: Ventilate vapors, prevent the boom, clear the room.