If you've been following the changes in classification descriptions and ratings (classes) published in the trucking industry’s National Motor Freight Classification (NMFC) over the past few years, you've probably noticed that more and more commodities are being classified on the basis of density (weight per cubic foot).

Classifying products based on their density is nothing new. Back in 1945, when National Motor Freight Classification No. 8 was in effect, only 12 different products were classified that way. By 1956, that number had risen to 26. Twenty years later, in 1976, nearly 180 separate article descriptions were subject to density ratings. Many more have been added since then.

When most people talk about density ratings, they generally are referring to the standard multiple scale of ratings based on density. Such scales have been established for numerous commodities that have a wide range in densities. Examples include stepladders, vacuum cleaners, and mail boxes, to mention just a few.

The standard scale includes nine density groups, with separate ratings (classes) applicable to each one, as shown below:

Over the past three or four years, the National Classification Committee (NCC) has broadened the standard scale, adding two more density groups and ratings for articles having densities of 15 pounds per cubic foot or greater:

Some examples of articles that are subject to the broader density scale include Games or Toys, NOI; Paper Goods, NOI; and Tarpaulins, Drop Cloths, or Covers, viz.: Traffic or Road Markers.

Density-based ratings can be structured in other ways, too. Many classification descriptions have just two, three, four, or five density groups, and some are not in conformity with the density groups found in the standard or broader density scales. One example is “Cones, marshmallow-cream filled” under Item 40020 of the NMFC. That item applies Class 200 when the density is less than 9 pounds per cubic foot. For cones with densities of 9 pounds per cubic foot or greater, the rating is Class 100.

A few descriptions apply only if densities fall within a specified range. A typical example is “Benches or Gliders, iron or steel with wood slats, KD flat, having a density in pounds per cubic foot of 15 or greater,” under Item 79890 of the NMFC. The applicable rating is Class 70.

You can seek relief from your present rating if the density of your products is significantly heavier than that of the other products covered by the applicable classification description. If that’s the case, they might warrant a lower rating under the NCC's Density Guidelines.

Let's say your products have an average density of 18 pounds per cubic foot, which would call for Class 70, but the average density of the other products covered by that description is 9 pounds per cubic foot, and the rating is Class 100. All other transportation characteristics being normal, I’d petition for a density break to be established within that description: one for 15 pounds per cubic foot or greater at Class 70 and the other for less than 15 pounds per cubic foot at Class 100.

The objective, whenever possible, is to separate your product from the pack and use that information to achieve a more favorable rating.