🔍 Key Concepts

• Flammable vapor behavior in enclosed spaces (heavier-than-air vapors settling low) • Purpose of mechanical ventilation when handling flammable liquids • What to do before vapors form vs. while vapors may be present

💭 Think About

• Think about whether you want vapors to have time to build up or to be removed as they are produced • Consider if shutting down or delaying ventilation makes an explosive atmosphere more or less likely • Ask yourself what the safest practice is during the entire time flammable liquids are being handled

✅ Before You Answer

• Verify what standard practice is for ventilation operation during the handling/transfer of flammable liquids • Consider whether ventilation should be continuous or intermittent when vapors might be present • Check which choice would prevent rather than react to an explosive mixture forming