This calculator will help you figure out the maximum gross mass of solid material that you can safely transport in your liquid rated container.
49 CFR 173.24a indicates that you can use drums (or any single or composite non-bulk container) with a U/N rating for liquids to ship solids. There are several formulas for calculating the maximum weight in solids that a liquid rated container can contain and still remain in compliance. We’ve compiled these formulas and built a calculator to help you remain in compliance. To use this calculator you’ll need to provide the packing group of the container, the rated capacity of the container in gallons and the specific gravity of the container. More information and the formulas can be found here.
Calculations are for single non-bulk packagings. More information can be found here 49 CFR §173.24a(b)(3)