🔍 Key Concepts

• Purpose of gas-freeing a tank before entry or hot work • Typical steps in tank cleaning and ventilation on tank vessels • Difference between removing residues and adding new chemicals/solvents

💭 Think About

• Think about the main goal of gas-freeing: what conditions must exist inside the tank before people can safely enter or do hot work? • Which options describe actions that normally help remove flammable/toxic vapors or residues from the tank? • Is there any option that might actually add more vapors or create an additional hazard instead of reducing it?

✅ Before You Answer

• For each choice, ask: does this step reduce vapors and hazards, or could it introduce additional dangerous fumes? • Identify which steps are clearly part of cleaning and ventilating (physical removal and air exchange). • Check which option sounds more like a special chemical treatment that could require extra controls rather than being a standard gas-freeing step.