CO2 cylinders must be recharged when the weight of the charge in the cylinder is less than what percent of the stamped full weight of the charge?

Correct Answer: Option C — 90%

Per 46 CFR and marine safety standards, fixed and portable CO2 cylinders must be weighed periodically. If weight loss exceeds 10% of the stamped full charge weight (meaning weight drops below 90%), the cylinder must be recharged or replaced immediately.