Where commodities are subject to Classification provisions which assign classes based upon density, a shipper may, at its option, increase the weight of the package(s) or piece(s) to artificially increase the density of the package(s) or piece(s) and apply the next lower class in the density scale to that increased weight, where the result would be a lower charge. THIS MAY ONLY BE DONE WHERE THE APPLICABLE PROVISIONS MAKE SPECIFIC REFERENCE TO THIS RULE AND MAY ONLY BE DONE AT THE TIME OF SHIPMENT.
    Bumping is accomplished by determining the actual cubage of the particular package(s) or piece(s) and multiplying that cubage by the lowest density named in the density group which provides the next lower class. The following example demonstrates the application of this rule.

A commodity which is classified per item 156600, naming 'Plastic Articles, NOI, other than expanded,' is shipped in a package which measures 40" x 48" x 54" and has a cubage of 60 cubic feet. The package weighs 300 pounds, thus the actual density (weight divided by cubic feet) equals 5 pounds per cubic foot (pcf).

Commodities with densities of 5 pcf are classed per sub 4 of item 156600 (4 but less than 6 pcf) which provides a class 150. The next lower class of 125 is provided in sub 5 of item 156600 (6 but less than 8 pcf).

To bump, the actual cubage of 60 cubic feet must be multiplied by 6 (the lowest density named in sub 5) to determine a declared weight for billing purposes of 360 pounds.

    In each instance where the provisions of this rule are utilized, the shipper must show on bills of lading and shipping orders at time of shipment the:
    (1) actual cube,
    (2) actual weight,
    (3) density group (sub) embracing the actual density,
    (4) declared density, and
    (5) resultant weight for billing purposes (declared weight) of the package(s) or piece(s) for which density is being bumped