How to choose a single UN certified packaging

Let's start with the definition of packaging, which, as stated on the ADR, means one or more receptacles and any other item or material necessary to enable the receptacles to perform their containment and other safety functions.
To better understand what single packaging is, we give ADR definitions of some types of packaging:

Inner packaging is "a packaging for which an outer packaging is required for carriage."
Outer packaging is "the outer protection of the composite or combination packaging together with any absorbent materials, cushioning and any other components necessary to contain and protect inner receptacles or inner packagings."
Combination packaging is the "combination of packagings for carriage purposes, consisting of one or more inner packagings secured in an outer packaging in accordance with 4.1.1.5."

To define what a single packaging is, let us consult the IATA regulations instead: single packaging is defined as packaging that does not require any inner packaging to fulfill its containment function during transport. In the case of single packaging, therefore, the dangerous goods are placed directly into a UN-certified packaging suitable for containing them.

Examples of simple packaging are:

HOW TO VERIFY THE SUITABILITY OF THE PACKAGING?

Even when shipping dangerous goods in single packaging, it is essential to check whether the packaging chosen is suitable for what is to be placed and shipped.

Let's take the case of dangerous goods transportation by road ADR.
We can summarize the verification of the chosen packaging in 3 basic step:

1^st STEP

Packing instruction: evaluate whether the reference packing instruction allows the shipment of single packaging.

For example, in packing instruction P010 that we have taken as an example, shipment of single packaging is allowed.

P010

Otherwise, if single packaging is not allowed, the entry "Single packaging" would not be in the table, such as in packing instruction P132 (b) below, where it is mandatory to use combination packaging (inner packaging + outer packaging:

p132b

2^nd STEP

Allowed packaging: check what types of single packaging are allowed by the reference packing instruction.

Let’s always take packing instruction P010 of the ADR regulation as an example.
In this case, the allowed single packaging are:

Steel drums with non-removable lids (1A1)
Steel jerry cans with non-removable lids (3A1)
Composite packaging, Plastic receptacle with steel outer drum (6HA1)

p010

3^rd STEP

Usable packaging: to make sure that the packaging chosen is suitable for the dangerous goods to be entered, with some exceptions, it must be verified that the packaging material does not react dangerously with the dangerous goods. In addition, depending on the contents, one must check:

FOR LIQUIDS

The relative density of the packaging
The hydraulic test pressure
For plastic packaging the date of manufacture
For plastic packaging the chemical compatibility

FOR SOLIDS

The maximum allowable gross weight

CHEMICAL COMPATIBILITY, HOW TO DO IT?

As stated in ADR Chapter 4.1.1.21, for shipping liquids in single polyethylene packaging defined in 6.1.5.2.6 and polyethylene IBCs defined in 6.5.6.3.5, chemical compatibility must be checked. One option is to verify chemical compatibility by assimilating cushioning materials to standard liquids as described from 4.1.1.21.3 to 4.1.1.21.5 and using Table 4.1.1.21.6.

WHAT STANDARD LIQUIDS WAS THE PACKAGING TESTED WITH?

Ask the supplier for the UN certificate, here you will find indicated the standard liquids used for tests.
Below you will find an example of how this information could be listed on a packaging UN certificate.

tab

TO WHICH STANDARD LIQUID IS MY DANGEROUS GOODS ASSIMILATED?

Check table 4.1.1.21.6 of the ADR to which standard liquid, the liquid to be shipped is assimilated, below are some examples.

tab

In cases where there is no proper UN number, chemical compatibility must be verified by prototype tests in accordance with Chapter 6.1.5.2.5 or by laboratory tests in accordance with 6.1.5.2.7 for packaging and 6.5.6.3.3 or 6.5.6.3.6 for IBCs, respectively.

3 DIFFERENT CASES MAY OCCUR DEPENDING ON THE LIQUID INDICATED

CASE 1

CASE 2

CASE 3

The standard liquid listed in the ADR is one of the standard liquids in the packing certificate, the packing is suitable.

The standard liquid listed in the ADR is NOT one of the standard liquids in the packing certificate, the packing is NOT suitable.

In the table, the standard liquid indicated is "Collettive entries". In this case, chapter 4.1.1.21.5 ADR should be consulted and complied with.