Shipment Types

Overpacks

Overpack, except as provided in subpart K of part 178 of this subchapter (i.e., radioactive materials packagings), means an enclosure that is used by a single consignor to provide protection or convenience in handling of a package or to consolidate two or more packages. Overpack does not include a transport vehicle, freight container, or aircraft unit load device. Examples of overpacks are one or more packages:

ICAO, IATA and IMDG definitions are essentially the same.

A few examples that we see rather frequently:

A shipment of 20 cases (fibreboard boxes) of UN 1263, Paint, Class 3, PG III. Each case contains four 5-litre metal cans. Each fibreboard box is addressed, marked and labeled and in proper condition for carriage. This type of packing is identified as "combination packaging."

The boxes are stacked tightly onto a wood pallet, and then shrink-wrapped. That is a typical overpack that you might see shipped by any mode of transportation.

The documentation for air would indicate UN 1263, Paint, Class 3, PG III, 20 Fibreboard Boxes x 20 Litres. “Overpack Used” Total net quantity 400 Litres.

The shrink-wrapped overpack would be marked and labeled in the same manner as the individual fibreboard boxes and additionally would be marked with the word “Overpack” and the total quantity (400 litres).

For highway and ocean the documentation would read:

UN 1263, Paint, Class 3, PG III, 20 Fibreboard Boxes @ 440 kgs.  “Overpack Used”

(note that gross weight is appropriate for highway, rail, and ocean)

All Packed In One

A shipment of 20 fibreboard boxes, each box contains 6 half-litre metal cans of UN 1263, paint, Class 3, PG III, and, 6 half-litre plastic bottles of UN 1805, Phosphoric Acid Solution Class 8, PG III. This method of packing is also a "combination package."

Our documentation for air would read:

UN 1263, paint, Class 3, PG III; 3 Litres P/I 309

UN 2834, Phosphoric Acid, Class 8, PG III 3 Litres P/I 819

All packed in one fibreboard box x 20

If we shrink-wrapped those 20 boxes to a pallet, only then does it become an overpack.

Background: In this example, we would have to determine first if the different hazard classes are compatible, requiring us to check the segregation tables. Yes, they could be packaged together safely.

By air, we also would be required to determine the "Q Value" to make sure that we have not exceeded the quantity limitations per package. The formula is Q = n1/M1 +  n2/M2

("Q" can not exceed the value of 1)

"n1" is the total net quantity of the first chemical that I intend to place in the package. "M1" is the total quantity of that first chemical that I can legally place in the package. In this example, by air, "n1" represents the six half-litre cans of paint that I intend to place in the box. UN 1263, Class 3, PG IIII, which is 3 litres.

M1 is the maximum quantity that we are permitted to place in the package - in this case, under Packing Instruction 309 by air, would be 60 litres.

Dividing 3 by 60 we end up with a (paint) value of 0.05 - rounded up to 0.1

"n2" is the total net quantity of the second chemical that I intend to place in the same package. "M2" is the total quantity of the second chemical that I can legally place in the package. In this example, by air, "n2" represents the six half-litre cans of paint that I intend to place in the box. UN 1805, Class 8, PG IIII, which is also 3 litres.

M2 is the maximum quantity that we are permitted to place in the package - in this case, under Packing Instruction 819 by air, would be 5 litres.

Dividing 3 by 5, we have a value of 0.6 for the phosphoric acid.

Adding 0.1 (paint) and 0.6 (phosphoric acid gives us a Q Value of 0.7

And, finally,

Unit load device means any type of freight container, aircraft container, aircraft pallet with a net, or aircraft pallet with a net over an igloo.