🔍 Key Concepts

• Dangerous liquid cargo classifications under 46 CFR (corrosive, toxic, flammable, etc.) • Differences between open, closed, and restricted gauging systems on tank vessels • How gauging requirements change for highly corrosive/toxic cargoes

💭 Think About

• Consider whether formic acid is treated as a hazardous/dangerous liquid cargo and what that implies for crew exposure during gauging. • Think about which gauging method minimizes vapors and physical contact with the cargo. • Ask yourself: for corrosive or toxic acids, would regulations allow free access to tank vapors, or require containment of vapors during measurement?

✅ Before You Answer

• Verify how formic acid is listed in the chemical/IGC or USCG tank vessel tables (e.g., as a corrosive, toxic, or both). • Check which cargo categories are not permitted to use open gauging under 46 CFR chemical/tank vessel rules. • Confirm the definition of each gauging method (open vs closed vs restricted) and match the safest allowable method for this specific cargo.