1.1   This practice provides a uniform basis of evaluating, in a laboratory, the ability of shipping units, weighing up to but not exceeding 150 lb (68 kg), intended for the single parcel delivery system to withstand the hazards associated with the distribution environment. This is accomplished by subjecting them to a test plan consisting of a sequence of anticipated hazard elements encountered in the distribution cycles. This practice is not intended to supplant material specifications or existing pre-shipment test procedures.