Gas can storage?

Can 5 gallon gas cans be stored on the stern of a inland towboat? I’ve heard they need to be in a vented box, i’ve heard they need to be in a flame proof container, ive heard if they are normal approved gas cans they can be stored outside. Ive looked for a cfr but cant find any. Is there a rule on this? Thanks.

Maybe…46 CFR 147.45 Flammable and combustible liquids.