Question 1 TK02 - Tank Vessel Assistant - Liquefied Gas

The Correct Answer is C **Why Option C ("Flammability") is correct:** The primary hazard associated with both Liquefied Petroleum Gas (LPG, which is mostly propane and butane) and Liquefied Natural Gas (LNG, which is mostly methane) is their inherent ability to burn rapidly and explosively when mixed with air and ignited. Both substances are stored as high-energy-density fuels. If containment is lost, the rapid vaporization and mixing with ambient air create a massive cloud of flammable vapor. Ignition of this vapor cloud (either immediately or after dispersion) is the main threat to life, property, and the environment. **Why the other options are incorrect:** * **A) Temperature:** While LNG is stored at extremely low cryogenic temperatures (-162°C) and can cause severe cold burns (frostbite) upon contact, and LPG is stored under moderate pressure at ambient temperature, temperature itself is a secondary hazard. The release of energy during combustion (fire) represents a far greater and more widespread danger than contact with the cold liquid. * **B) Toxicity:** Neither methane (LNG) nor propane/butane (LPG) are chemically toxic in the sense that they poison the body. They are considered simple asphyxiants, meaning that in very high concentrations, they displace oxygen and can lead to suffocation. However, this asphyxiation risk is a minor concern compared to the catastrophic flammability hazard. * **D) Pressure:** Both LPG and LNG are typically stored or transported under pressure (or high pressure in the case of some LPG storage). While pressure is necessary to maintain the liquefied state and its sudden release can cause equipment damage, the pressure itself is a mechanism for release, not the primary danger of the substance once released. The primary hazard stemming from a catastrophic release is the ignition of the resulting fuel vapor.