The gross weight of a fully charged CO2 cylinder is 80 lbs. When the bottle is empty it weighs 60 lbs. What is the minimum acceptable gross weight of the CO2 bottle before it should be recharged by the manufacturer?

Correct Answer: Option C — 78 lbs

Per 46 CFR maintenance standards, carbon dioxide cylinders must be recharged if weight loss exceeds 5% of the charge or 10% of total capacity. Here, net capacity is 20 lbs; a 10% loss equals 2 lbs, establishing 78 lbs as the minimum allowable gross weight.