49 CFR § 173.188 - White or yellow phosphorus.
Phosphorus, white or yellow, when offered for transportation or transported by rail, highway, or water, must be packaged in water or dry in packagings conforming to the requirements of part 178 of this subchapter at the Packing Group I performance level, as follows:
(a) When placed in water, it must be packaged in specification packagings as follows:
(1) Steel, aluminum or other metal boxes (4A, 4B or 4N) or wooden boxes (4C1, 4C2, 4D, or 4F) with:
(i) Inner hermetically sealed (soldered) metal cans, enclosed in other hermetically sealed (soldered) metal cans, or
(ii) Inner water-tight metal cans containing not over 0.5 kg (1 pound) of phosphorus with screw-top closures; or
(2) Steel, aluminum or other metal drums (1A1, 1B1 or 1N1) not over 250 L (66 gallons) capacity each or steel, aluminum or other metal drums (1A2, 1B2, or 1N2) not over 115 L (30 gallons) capacity each.
(3)
(i) A 115 L (30 gallon) UN1A2 steel drum certified to the PG I performance level for solids and the PG I or PG II performance level for liquids and dual marked, at a minimum, as a UN1A2/X400/S (for solid) and UN1A2 X(or Y)/1.4/150 (for liquids) subject to the following conditions:
(ii) Enough water must be present in each drum to ensure that the phosphorous is covered by water at all times during transportation, in any orientation of the drum;
(iii) Drums must be held and observed for a minimum of 24-hours before transportation. Any leaking or otherwise unsuitable drums must be replaced prior to transportation;
(iv) Packages must be destroyed and may not be reused;
(v) The net mass of the material and water, in kilograms, must not exceed the mass that would be permitted by calculating the volume of the packaging in liters multiplied by the specific gravity indicated on the package certification;
(vi) Transportation is by private or contract motor carrier only; and
(vii) Transportation is authorized from the offeror's location to a facility where it must be unloaded by the consignee.
(b) When dry, it must be cast solid and shipped in packagings as follows:
(1) Steel, aluminum or other metal drums (1A2, 1B2 or 1N2) not over 115 L (30 gallons) capacity each, or
(2) In projectiles or bombs when shipped by, for, or to the Departments of the Army, Navy, or Air Force of the United States Government, without bursting elements.