🔍 Key Concepts

• Behavior of LPG (liquefied petroleum gas) vapors in a leak or spill • Comparison of gas density to air and how that affects where vapors accumulate • Why some gases rise and others sink in an enclosed space

💭 Think About

• If LPG leaks on deck or in an engine room, where would you expect the vapors to collect: near the deck/head level or up near the overhead? • How does the relative density of a gas compared to air affect ventilation and gas detection placement on a vessel? • Think about common safety warnings around LPG in galleys or small craft—are you more worried about low spaces (bilges) or high spaces?

✅ Before You Answer

• Recall that LPG is commonly propane/butane mix and how those vapors behave • Consider whether LPG detectors are usually mounted high or low in a space • Verify which option matches a gas that tends to settle in bilges and low areas rather than rise and disperse quickly