49 CFR 178.519 - Standards for plastic film bags.
(a) The identification code for a plastic film bag is 5H4.
(b) Construction requirements for plastic film bags are as follows:
(1) Bags must be made of a suitable plastic material. The strength of the material used and the construction of the bag must be appropriate to the capacity and the intended use of the bag. Joints and closures must be capable of withstanding pressures and impacts liable to occur under normal conditions of transportation.
(2) Maximum net mass: 50 kg (110 pounds).