(a) The following are the identification codes for metal drums other than steel or aluminum:
(1) 1N1 for a non-removable head metal drum; and
(2) 1N2 for a removable head metal drum.
(b) Construction requirements for metal drums other than steel or aluminum are as follows:
(1) Body and heads must be constructed of metal (other than steel or aluminum) of suitable type and adequate thickness in relation to the capacity and the intended use of the drum. Minimum thickness and marking requirements in Secs. 173.28(b)(4) and 178.503(a)(9) of this subchapter apply to drums intended for reuse.
(2) All seams must be welded. Chime seams, if any, must be reinforced by the application of separate reinforcing rings.
(3) The body of a drum of a capacity greater than 60 L (16 gallons) may have at least two expanded rolling hoops or two separate rolling hoops. If there are separate rolling hoops, the hoops must be fitted tightly on the body and so secured that they cannot shift. Rolling hoops may not be spot-welded.
(4) Openings for filling, emptying, or venting in the bodies or heads of non-removable head (1N1) drums may not exceed 7.0 cm (3 inches) in diameter. Drums with larger openings are considered to be of the removable head type (1N2). Closures for openings in the bodies and heads of drums must be so designed and applied that they will remain secure and leakproof under normal conditions of transport. Closure flanges may be welded in place so that the weld provides a leakproof seam. Gaskets or other sealing elements must be used with closures unless the closure is inherently leakproof.
(5) Closure devices for removable head drums must be so designed and applied that they remain secure and drums remain leakproof under normal conditions of transport. Gaskets or other sealing elements must be used with all removable heads.
(6) Maximum capacity of drum: 450 L (119 gallons).
(7) Maximum net mass: 400 kg (882 pounds). [Amdt. 178-97, 55 FR 52717, Dec. 21, 1990, as amended at 56 FR 66285, Dec. 20, 1991; Amdt. 178-102, 59 FR 28494, June 2, 1994]