Using the List of Packing Instructions

To best understand the use of the List of Packing Instructions, it is helpful to look at an entry in the Dangerous Goods List (IMDG Code Part 3, bound in Volume 2). Open the DGL, look for the heading "UN No." in the left hand column. This column shows the four-digit UN numbers for each item in sequential order. Locate the UN Number 1791. (In the print version of the IMDG Code book, this is found on page 87). This is the listing for HYPOCHLORITE SOLUTION. Diluted solutions of hypochlorite are sold as household bleach. Note that there are two entries for 1791. The first is for packing group II. The second is for packing group III. We will focus on the first listing.

Look across the row, and stop at the column that says "P001." This refers to Packing Instruction number 101. Next to this, we see a packing provision listed as PP10. Note that in the next four columns there are also listings for IBC and tank transport methods, also with provisions. For now, we will focus on the packaging instruction P001 and the provision listed.

Returning to Volume 1, Part 4, locate Section 4.1.4. This is the first page of the List of Packing Instructions. Note the format of the table seen there. The first line of the table shows the packing instruction number. In this case it is P001, the packing instruction designated for UN 1791, HYPOCHLORITE SOLUTION. The second line of the table indicates which provisions must be met in order for this packaging method to be valid. After this, the lines appearing in each instruction may vary. Where applicable, the table will show acceptable single and combination packagings. The combination packagings will be further broken down into acceptable outer packagings, inner packagings, and the maximum quantity allowable in each inner or outer packaging. For example, in P001, the inner packagings may be glass, plastic, or metal, but they are limited to the liter volumes shown.

You may note that the specific items listed under "Outer packagings" are followed by a number in brackets (for example, steel (1A1, 1A2)). These designations refer to specifications outlined in Part 6, Section 6.1, which describe the packaging type in detail (for example, see 6.1.4.1 to locate the information about the steel drums specified in P001; this material will be covered in a future lesson). Now, reading across the P001 table, you will note that three Packing Group designations are listed. You may recall from previous lessons that goods in certain classes may be given Packing Group I, II, or III designations based on the severity of the hazards they present. Packing Group I is given to goods that present the greatest hazard, II to intermediate hazards, and III to the least hazardous. In the packing instructions, Packing Group levels dictate the maximum capacity or maximum net mass allowable for a given outer packaging type. For our example, UN 1791, which showed a Packing Group of II or III, we can see that there would be no change in the maximum capacity or net mass allowable across all outer packaging types.

Finally, you may recall that UN 1791 carried a packing provision shown as "PP10." Where they are present, packing provisions are shown at the bottom of the packing instruction tables under the heading "Special packing provisions." For P001, there are several provisions listed. Under PP10, it states "For UN 1791, for packing group II, the packaging shall be vented." With that, the entire instruction for the packaging of HYPOCHLORITE SOLUTION in containers other than IBCs or tanks has been provided. The procedure for learning the packing instructions for any dangerous good, regardless of the packaging type, follows the same sequence.

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