Last reviewed 22 August 2012

Desmond Waight looks at the safe carriage of dangerous goods in packages.


To ensure the safe carriage of packaged dangerous chemicals from one place to another a number of elements must come together to form a chain of compliance under the applicable regulatory provisions.

The elements in the chain are: training, classification, packaging, labelling and/or marking, documentation, loading, stowage, segregation, and unloading. The failure of any one of these elements can lead to potentially life-threatening or life-changing consequences.

While a correct, or at least an adequate, classification is very important, the critical role that packaging plays is to ensure that during the carriage there is no exposure to, or leakage of, the dangerous chemical that would result in risks to the health or safety of the workers involved, or the general public; or risks to the environment.

These days, through the work carried out initially by the UN Committee of Experts on the Transport of Dangerous Goods (UNCETDG), and more recently by the UN Sub-Committee of Experts on the Transport of Dangerous Goods (UNSCETDG), the regulatory requirements, including those for packaging, are usually agreed at the UN level. They are then published in the UN ECE Recommendations on the Transport of Dangerous Goods — Model Regulations (the “Orange Book”, or “UNRTDG”). These are revised on a two-year cycle, with the most current version being the 17th revised edition which was published in 2011.

In the late 1980s the UN developed the system of packaging sometimes described as “performance orientated packaging” that is used today, and which has been applied by the modal legislators since the early 1990s; albeit with the occasional modal variation on the UN recommended scheme.

In this feature we consider only the packaging, and packaging related, requirements as set out in ADR (the European Agreement concerning the International Carriage of Dangerous Goods by Road), which are applied domestically in the EU Member States (MSs), including the UK, in consequence of the requirements of the Directive 2008/68/EC — inland transport of dangerous goods (ITDGD); albeit for certain derogations available for domestic only transport.

Please note that this feature will not cover packaging for Class 1 (Explosives), Class 2 (Gases), Class 6.2 (Infectious), or Class 7 (Radioactives).

The requirements of the International Maritime Dangerous Goods (IMDG) Code, which covers sea, being very, very similar.

However there are a number of additional requirements laid down in the air requirements, the legally applicable International Civil Aviation Organisation (ICAO) Technical Instructions (Tis) as reproduced also in the International Air Transport Association (IATA) Dangerous Goods Regulations (DGRs), which despite the name, are actually only terms and conditions of contract.

Training in packaging

Before anyone undertakes a duty in relation to packaging dangerous goods that will be carried, ADR requires (Chapter 1.3) that a person shall be trained in the requirements concerning packaging appropriate to their responsibilities and duties, and before commencing those duties.

This applies to those whose job is to physically pack the goods. For example, a failure to train in the proper application of the clinching tool used to close multi-lug pails, can lead to leakage from the pails during transit. This indeed did occur on a vehicle travelling from France to the UK carrying flammable adhesives, and on arrival the atmosphere in the back of the vehicle was found to be in the explosive atmosphere region (ie above the Lower Exposure Limit and below the Upper Exposure Limit). If this had been ignited on a ferry crossing of the Channel, the consequences could have been dire.

The training requirement also applies to those whose job is to decide which sort of packaging shall be used for each dangerous good to be carried.

Training in packaging issues is also required for those who may subsequently handle packages prepared for shipment, eg those who may unitise a number of different dangerous goods into what is called in ADR an “overpack”. An overpack being defined as "an enclosure used (by a single consignor in the case of Class 7) to contain one or more packages, consolidated into a single unit easier to handle and stow during carriage”. Overpacks are created by simply placing a number of packages onto a pallet and securing them with banding, shrink or stretch wrapping, or by placing several packages into some outer protective packaging such as a box or crate.

The training requirement essentially applies to all sorts of dangerous goods being carried, including dangerous goods packed in Limited Quantity (LQ) packages (see later) and those packed in Excepted Quantity (EQ) packages (see later), though the training only needs to be appropriate to the responsibilities and duties of the people concerned.

As always, there are a few special cases where training is not required. For example for UN 3373 BIOLOGICAL SUBSTANCE CATEGORY B, under which many samples provided by patients are shipped, special provision 319 is applied in the dangerous goods list to such goods. This however, does require compliance with packing instruction P650, which requires that clear instructions on filling enclosing the packages shall be provided by the manufacturers and substances and distributors to the person who prepares the package (eg the patient) to enable the package to be properly prepared for carriage.

As always, there are a few special cases where training is not required. For example, for UN 3373 BIOLOGICAL SUBSTANCE CATEGORY B, under which many samples provided by patients are shipped, special provision 319 is applied in the dangerous goods list to such goods. This, however, does require compliance with packing instruction P650, which requires that clear instructions on filling and enclosing the packages shall be provided by the manufacturers and distributors of substances to the person who prepares the package (eg the patient) to enable the package to be properly prepared for carriage.

Training in relation to packaging issues shall at least cover:

  • familiarisation with the general requirements for the carriage of dangerous goods

  • function-specific training in relation to packaging tasks that the employee will perform.

Unfortunately, ADR uses the words “general awareness training” as the heading for the requirement to be given training to familiarise the person with the general requirements for the carriage of dangerous goods. Also, unfortunately, ADR does not provide the explanation, which is provided in the UN Orange Book, as to what this familiarisation training should include. The UN Orange Book (1.3.2 (a)) indicates that such training should include:

  • a description of the classes of dangerous goods

  • requirements for packaging, labelling, marking, segregation and compatibility, and placarding

  • description of the purpose and content of the dangerous goods transport document

  • description of available emergency response documents.

Function specific training involves training the person in the specific dangerous goods transport requirements which will be applicable to the function that the particular employee will be performing.

As a result it is often the case that people who have received a “General Awareness” training are incorrectly assumed to have had appropriate function specific training in packaging.

Records of the training received shall be kept by the employer, with sufficient detail to show the Competent Authority (CA) the extent and depth of the training provided (which a certificate of training alone often fails to do).

The training should be periodically supplemented with refresher training as necessary, especially when needed to take account of changes in regulations. Here it should be stressed that changes in packaging requirements happen with every new edition of ADR. Therefore, consideration of refresher training should be addressed at the end of every even-numbered year.

This feature does not constitute function specific training in relation to packaging issues. Its aim is to highlight the areas that have to be taken account of.

Determining which sort(s) of packaging are permitted

Though in some cases classification is dependent on the packaging that will be used, in most cases decisions on the type(s) of packaging allowed will follow on from the classification decision.

Once the classification is available for the dangerous goods the first action should be to determine whether or not any “special provision” which may be listed in column 6 of the dangerous goods list (DGL) (ADR Chapter 3.2 Table A) has any packaging significance. For example, in the case of wipes wetted with a flammable liquid these would be allocated by the classifier to UN 3175 SOLIDS CONTAINING FLAMMABLE LIQUID, N.O.S. This classification has two special provisions allocated, SPs 216 and 274, of which only SP 216 has packaging relevance (in that it exempts from being considered as dangerous goods when packed in sealed sachets meeting certain conditions).

The next thing to consider is whether the quantities per receptacle and the package chosen are likely to be such that packages can be designed to comply with the more relaxed rules of the LQ packaging or EQ packaging provisions of ADR. These will be covered later.

However, presuming that the LQ or EQ relaxations are unlikely to be applicable, eg where carriage in drums or Intermediate Bulk Containers (IBC) or large packages is required, then the next step is to look up the one or more Packing Instructions (PI) assigned to the particular dangerous goods in Column 8 of the DGL, and any Special Packing Provision(s) in Column 9 that may be applicable.

It is important that the correct entry line is chosen. A UN number may have several different lines, eg when it applies to more than one Packing Group.

Packing Groups were introduced when the UN was developing its performance orientated packaging provisions as a way of distinguishing different degrees of hazard to a hazard class, in order that an appropriate level of packaging of performance could be assigned. These often will equate to the Category assigned to a hazard under the GHS system, as implemented in Europe by the Regulation (EC) No. 1272/2008 on classification, labelling and packaging of substances and mixtures, amending and repealing (in June 2015) Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No. 1907/2006 (known as CLP). For example, Class 3 PG II is equivalent to CLP Flammable Liquid Category 2.

The PIs are prefaced by letters indicating the type of packages to which they refer.

  • “P” relates to the various “traditional” or “general” package types (eg tins in boxes, drums, etc). There is always a P instruction assigned for the classes this article is covering.

  • “IBC” relates to Intermediate Bulk Containers, if allowed.

  • “LP” relates to large packages (these start at 400kg/450 litre minimum size), if allowed.

  • “R” (or just R001), if allowed, relates to a special package type allowed for use only under ADR/RID/ADN provisions. They are not permitted by the sea mode. Accordingly, they are not generally used and will not be considered further here.

Special Packing Provisions, if any, apply to the particular package type as below.

  • “PP” prefaced relates only to “P” prefixed instructions.

  • “B” or “BB” prefaced relates only to “IBC” prefixed instructions (Note: BB codes are only applicable to ADR and RID).

  • “L” prefaced relates only to “LP” prefixed instructions.

  • “RR” prefaced relates only to “R” prefixed instructions.

Where more than one PI is indicated a decision can then be taken as to which of these basic types (P — general, IBC, or Large) of packaging one wishes to try and use. This type of package is often called a “fully regulated” packaging to distinguish it from the LQ and EQ packages which get a number of relaxations from the full requirements.

“Fully regulated” packaging

Having chosen, if there are options, which basic type of packaging to use the next step is to consult the applicable Packing Instruction for details of what is required.

For example, for UN 1993 PG II there are two possible line entries to be considered, with the decision dependent upon the vapour pressure. Assuming that the vapour pressure at 50°C is less than 110kPa, then PIs P001, IBC02 and R001 could be used. However, as R001 is not applicable to sea, it shall not be discussed further here.

Assuming that the use of IBCs is not required, this leaves P001 to be considered. P001 provides for the use of several different package types.

  • Combination packagings: one or more inner packagings secured in outer packagings (with the inner packagings being filled and emptied without the outer packagings), eg six tins in a corrugated fibreboard box closed by pressure sensitive sealing tape.

  • Single packagings: ie just drums or jerricans (and not other forms of single packages — such as plastic film bags, stoneware receptacles).

  • Composite packagings: one inner packaging within an outer packaging that once assembled is filled, stored, carried, and emptied as a unit.

  • Pressure receptacles.

Assuming that the company wishes to carry the product in combination packages, then P001 permits only one of three inner packaging types.

  1. Glass packagings up to a maximum of 10 litres each.

  2. Plastics packagings up to a maximum of 30 litres each.

  3. Metal packagings up to a maximum of 40 litres each.

These inner packagings may be carried in one of three types of outer packaging.

  1. Drums (which can be any of six different types).

  2. Boxes (which can be any of eight different types).

  3. Jerricans (which can be any of three different types).

Assuming the company wishes to use glass inner packagings of 2.5 litres and package only 6 bottles per outer fibreboard box, this will meet the restrictions on the inners and easily be under the maximum net mass of 400kg assigned.

The code “(4G)” mentioned after the fibreboard box is quite well recognised as being an indication that the total package (glass inners, fibreboard box outer, closure tape and any internal fittings) must conform to a successfully tested design type approved by a CA according to the UN Orange Book scheme for package approvals.

However, many failed to note the text at the top of the PI which states “the following packagings are authorised provided the general provisions of 4.1.1 and 4.1.3 are met”. Of these for our example only 4.1.1 is pertinent.

General packaging requirements 4.1.1

The general packaging requirements of ADR 4.1.1 are often overlooked. These requirements are detailed and it is not possible to cover all the issues in this feature. However, the following aspects are of interest and are brought to the attention of readers.

Paragraph is in many ways a general statement requiring packages to be suitable for their intended journey. This can, however, mean that the use of an allowed package that has UN package approval may not be sufficient. In the case of our example, the use of glass receptacles might not be considered appropriate if the packages were to be transported into Siberia in unheated vehicles in the winter, with a consequent risk of freezing of the contents and breakage of the glass.

However, particular attention needs to be taken to the requirements that appear about two thirds of the way through this paragraph where it says that “Packagings, including IBCs and large packagings, shall be closed in accordance with the information provided by the [package] manufacturer”. These instructions may specify the closure torque to be applied when closing drums or the way that the fibreboard box closure tape shall be applied, including the length of application. Experience has shown that many are unaware of this requirement and failed to have the necessary closure instructions.

Compliance with closure instructions is particularly important in the case where a package is reused. Examples include slitting open the closure tape to access the inner receptacles to inspect or re-label them, which may require the use of a different quality of tape when it comes to reclosing the boxes before reshipment. Also, reuse of a supplied product drum for waste dangerous goods (as any closure instructions will not, normally, have been provided by the product supplier).

In addition, in paragraph 4.1.1 there is a requirement that no dangerous residues adhere to the outside of packagings. This can sometimes pose difficulties, as demonstrated in the above photograph of a drum from a load of dangerous wastes, stopped during a police check.

Paragraph requires that the packagings in contact with the dangerous goods shall be resistant to them. This can be a significant issue in relation to plastics, and to compatibility of metal containers with some dangerous goods.

Paragraph requires that in general the complete packages shipped shall conform in all respects to the successfully tested design type that was approved. Due to the requirements of ADR 6.1.3 the package shall also bear the allocated “UN” package approval mark, eg (UN) 4G/Y30/S/12/GB/DCW123. In order to verify that the package conforms to the approved design type it is necessary for the person carrying out the packaging to be in possession of the full test report, which under ADR and shall be made available to users of the packaging.

Paragraph requires that the package is not overfilled, so that in the case of increased temperature, failure of the package shall not occur.

Paragraph relates to inner packaging requirements such as in the example ensuring that the closures on the bottles shall be positioned upwards, and be placed within outer packagings consistent with the required this way up arrows that are required under As in our example using glass bottles, this paragraph requires that they are secured within the outer with suitable cushioning material.

Paragraph restricts the mixed packing of different dangerous goods that will react — but note that ADR has other mixed packing (different goods (not restricted to just dangerous goods) within the same package) rules that may apply as well. These are not discussed further here.

Paragraph requires that the inner receptacles shall have the appropriate resistance to any internal pressure that may be developed. This will need information about the pressures that may be developed (which is often hard to get) and the resistance capabilities of inner packagings (which may be equally hard to get from the inner packaging supplier). Paragraph has more specific provisions relating to the pressure capacity of single receptacles.

Paragraph requires packages, whether new or reused, to be capable of passing the design type tests. They also require that packages shall be inspected before handing over for carriage to ensure that they are free from corrosion, contamination, or other damage which may affect their suitability for carriage.

Paragraph requires that empty packages, which are still dangerous because of the presence of residues, are subject to the same requirements as those for a filled package.

Additional IBC requirements

In the general packaging requirements of 4.1.1 there are certain specific issues relating to IBCs which should be mentioned.

Where an IBC is to be used for the carriage of liquids, and the IBC is fitted with a bottom discharge, the bottom discharge has, per ADR, to have a secondary sealed closure (such as a blank flange). ADR then, under, requires that the one nearest the substance being carried shall be closed first.

A commonly seen problem is that the secondary closure is missing, as shown in this photograph of an IBC carrying dangerous waste goods stopped in a police inspection (where the secondary closure flange is missing).

Relaxations from fully regulated

ADR provides two schemes of packaging offering some relaxation from the “fully regulated” requirements.

Both schemes, however, do require training, as appropriate to the responsibilities and duties of the individual concerned.

Limited quantity

For ADR this is the older of the two schemes of relaxed packaging requirements. It was developed in the 1980s principally as a result of concerns from the paints, adhesives and printing ink industries over the impending introduction of the UN performance packaging requirements.

These industries have had a very successful use of lever lid tins in outer packagings for the movement of their dangerous goods products, but the packages in use could not readily and economically be adjusted to pass the UN performance test requirements; particularly the drop test requirement onto the side and corner.

As a result of a co-operative project between these industries and PIRA, the UN adopted the original limited quantity provisions, although these have been subject to many amendments since then. While ADR is now essentially aligned with sea freight in relation to limited quantity packages, there are still significant differences for limited quantity packages carried by air.

The current requirements are found in ADR chapter 3.4, which was substantially amended with effect from the ADR 2011 edition. These permit the use of limited quantity packaging provisions (note — not to be confused with small load provisions).

The basic requirements are that each receptacle shall not contain more than the amount specified in Column 7a of the DGL, and that they shall be suitably packaged in a combination package with a gross mass that shall not exceed 30kg. In the case of UN 1993 PG II, it would be necessary to reduce the size of the glass bottles from 2.5 litres to 1 litre to make them acceptable for the LQ package scheme. (Note: where “0” is assigned, this means that the scheme is not available for that specific dangerous good, eg UN 1993 PG I cannot be shipped as LQ.)

Paragraph 3.4.1 specifies that other parts of ADR do not apply except for certain specified areas, such as compliance with chapter 1.3 on training as mentioned above.

In relation to packaging it is worth noting that while 3.4.1 refers to certain paragraphs of Part 4, those references do NOT include which generally requires the use of a “UN approved package” nor, which requires packages to be capable of passing the UN performance testing.

However, other references to the ADR general packaging requirements of 4.1.1 are still applicable, such as a requirement for packages to be closed in accordance with information provided by the “manufacturer” (which could mean the instructions of the person responsible for the package design to be used).

Although the LQ packaging scheme was originally developed only to address the problems and costs that compliance with the UN performance orientated packaging would cause, there are a number of other relaxations that make use of the LQ scheme, where possible, advantageous.

Excepted quantity

The ADR excepted quantity (EQ) packaging scheme is a more recent introduction, and it follows the extension of a scheme, originally only applied in the air mode, to all modes.

The requirements are found in ADR chapter 3.5, which was introduced with the ADR 2009 edition. The concept of the scheme is that very, very small quantities (from a maximum allowance of 30g/ml down to a maximum of 1g/ml according to the E code allocated) of certain dangerous goods in very protective “triple layer” but small content (maximum from 1000g/ml down to 300g/ml) packages can be treated almost as if they were non-dangerous goods. Only dangerous goods entries for which a code other than “E0” is listed in column 7b of the DGL are eligible for the scheme.

Since the scheme is designed to be multimodal, the packaging provisions are extensive. As with LQ provisions, the other parts of ADR do not apply except as specifically referenced in chapter 3.5. In relation to packaging requirements, those of (ie compliance with closure instructions, including if they are reused), (compatibility of the receptacle with the contents), (sufficient ullage) and (mixed goods compatibility) are applicable.

In 3.5.2 further packaging provisions are laid down, relating to the inner packaging, the use of an intermediate packaging, and the use of an outer packaging. Regardless of the quantity of dangerous goods that may be contained within the package, each package must be of such a size that there is adequate space to apply the necessary mark; ie at least one side of the package shall be at least 100 × 100mm.

In addition to the specification of the EQ package, mandatory design type test requirements are prescribed, which must be appropriately documented. However, these do not need to have CA approval, and no special package compliance mark is required.

The biggest advantage to the EQ scheme is that packages prepared in compliance with ADR chapter 3.5 also meet the requirements, other than transport of dangerous goods documentation, for sea and air.

There is, however, a limit of 1000 EQ packages for any vehicle or freight container.

UK derogations

In the Approved Derogations and Transitional Provisions (ADTP) (April 2012 edition) that support the Carriage of Dangerous Goods and Transportable Pressure Equipment Regulations 2009 (SI 2009 No. 1345, ie CDG 2009), as amended, there is a useful derogation from the ADR provisions.

Road Derogation 4 (retail distribution by road) provides for the carriage of “naked” receptacles (inner packagings) that have been taken from LQ and fully regulated combination packages during the final stages of the distribution chain, and any consequential initial returns that are sent back up the distribution chain.

There are of course certain conditions. This derogation is vital, for instance, to enable supermarkets to engage in home deliveries of customer orders.


The safe carriage of dangerous goods in packages depends on the appropriate training of all those who perform some sort of packaging function that could affect the safe carriage of those dangerous goods and compliance with the detailed requirements laid down in ADR. We have tried in this feature to highlight some of the issues involved, but this does not replace the need for appropriate training and compliance with all the ADR detailed requirements.