The DG Shipping Process – Part 3: Marking & Labeling (Step 4 & 5 of 7)

By Terry Poland, Principal Instructor and Consultant

Shipping dangerous goods for the first time?  Or perhaps it has been awhile, and you just need a quick review of the process.  Where to begin and what are the basic steps to follow?  Airlines MUST use a checklist, but shippers and others are not required to – especially for surface modes such as ocean and ground transport.  So what do we recommend?  The answer is simple: a process that provides shippers with step-by-step guidance to assure all aspects of compliance are addressed in a logical order.  While this process is not as detailed as the IATA Acceptance Checklist, generally it can be applied to all modes of transport – air, ocean or ground (highway and rail).

  1. Identification – Proper Shipping Name (with technical name for N.O.S. entries) & UN/Identification Number.
  2. Classification – Hazard Class and/or Division (subsidiary hazards, if any) & Assignment to Packing Group (PG I, II or III, if applicable).
  3. Packaging – UN Specification, Limited Quantity (LTD QTY), Excepted Quantity (EQ) and/or other exceptions granted by special provisions or packing instructions.
  4. Marking – Proper Shipping Name, UN/Identification Number, From & To Addresses, Quantity (if applicable), other shipment-specific markings as required.
  5. Labeling – Primary & Subsidiary Hazard Labels & Handling Labels (Orientation Arrows, CAO, others as applicable).
  6. Documentation – Shipping Paper (Dangerous Goods Declaration, Transport Document, Air Waybill, Bill of Lading, etc.).
  7. Other – Placarding/Special Provisions/State Variations/Operator Variations/Carrier Matters.

In Part 1 of this series, we covered Steps 1 & 2, Identification & Classification of the material.  In Part 2 we covered Step 3, Packaging, where the shipper determines the quantity and type of packaging for the material. 

In this article, Part 3, we will cover Steps 4 & 5, Marking & Labeling.  Before beginning this discussion, it is important to note that Marking & Labeling are two completely separate steps.  And then, within each of these two steps, there are essentially two types of markings and two types of labels to consider.  Therefore, we will cover Marking separately from Labeling such that we can fully understand the unique requirements of each.

Step 4 – Marking:

Again, there are two types of markings.  First, there are those which identify the design or specification of the packaging, irrespective of its use for a particular shipment (such as UN specification markings and in some cases, DOT or other governmental specifications – such as for compressed gas cylinders), or simply, “Specification Markings.”  And second, those marks which identify the particular use of a packaging for a particular substance (such as the UN/ID number and proper shipping name), or simply, “Packaging Use Markings.”

First, the most common type of Specification Markings are those indicating the use of UN specification packagings, which indicate that packagings are tested and certified based on the regulations found in Part 178 of 49 CFR or Section 6 of IATA or Section 6 of the IMDG.  Their use – when qualified by the applicable modal regulation – generally allows them to be used for multimodal applications.  For example, a steel drum may be tested and certified for use in carrying liquids, but must meet a minimum pressure requirement of 95 kPa (15 psi) to be used in air transport.   In any case, the actual Specification Markings (code) must be placed upon the packaging by the manufacturer or certified testing facility, but are still ultimately the responsibility of the shipper.  In other words, the testing facility must actually record the specification markings on the packaging, but the shipper must use the correct packaging based on their interpretation of that marking and the requirements of the actual material being transported.  Although this series does not cover the interpretation of UN specification code in detail, the image below and IATA summary provides an overview of how to read the code for a fiberboard box (combination packaging) and a drum (single packaging).

UN Specification Markings
  • IATA (summary) The marks must consist of:
  • (a) UN symbol:
  • (b) Code for the type of package (4G = Fiberboard Box)
  • (c) Code for the packing group which the design has been successfully tested:
  • “X” = PG I, (or II, III)
  • “Y” = PG II, (or III)
  • “Z” = PG III
  • Followed by the gross weight limit in kilograms
  • (d) For packagings intended to contain solids or inner packagings, the letter “S”
  • OR for drums & jerricans (c & d repeated)
  • (c) The specific gravity allowed for liquids
  • (d) The hydrostatic test pressure in (kPa)
  • (e) The last two digits of the year the packaging was manufactured (2019)
  • (f) The state (country) of manufacture (USA)
  • (g) The name or mark of the manufacturer/test facility

Second, there a number of Packaging Use Markings required for all modes of transport.  These markings indicate the details about the shipment particulars and include the following:

  1. UN or ID number (together with the prefix as applicable).
  2. Proper Shipping Name (as shown in the DG list or Hazmat Table).
  3. Name & address of the shipper.
  4. Name & address of the consignee.
  5. Note 1: Air shipments require both shipper and consignee information; ocean shipments require neither; ground shipments require one or the other, but not both.  In any case, we recommend marking both shipper and consignee information on all packages for all modes of transport.
  6. Note 2: Per the limited quantity exception, most surface shipments (ocean or ground) only require the limited quantity mark and do not require that the UN number and proper shipping name be marked on such packagings.

Additional Packaging Use Markings which are shipment-specific only apply to certain modal or shipment types:

  1. Air Only: The total net quantity of hazmat in the package (only required when the shipment consists of multiple packages with different contents/quantity).
  2. Limited Quantities: Limited Quantity Mark (label); air shipments require this mark bearing the letter “Y” and non-air shipments require only the mark.
  3. Small/Excepted Lithium Batteries: Excepted Lithium Battery Mark (Label) with the UN number and informational telephone number must be marked on packagings containing excepted lithium battery shipments with some exceptions noted in various modal regulations.
  4. Excepted Quantities (all modes): EQ Mark with hazard class/division and shipper or consignee name and address.
  5. Note: There are other required use markings which are “shipment specific” and are detailed in the various modal regulations.
  6. Reportable Quantities: “Reportable Quantities” must be marked with the letters “RQ” next to the basic description (Proper Shipping Name & UN/ID Number) of the hazardous material per 49 CFR 172.101, Table 1 to Appendix A.
  7. Overpack: Marking the word overpack is required when one or more packages is enclosed in a manner that provides for a single handling unit such as a large cardboard box or shrink wrap (for the purpose of providing convenience in handling).  All markings and labels on packages within an overpack must be visible or reproduced on the outside of the overpack – and the word “OVERPACK” must be marked on the outside of the overpack itself (unless all marks and labels are fully visible).

There are several additional package markings required for Class 2, refrigerated liquids, Biological Substances in Division 6.2 and Chemical Oxygen Generators.  See the modal packing and marking instructions for these requirements.

Step 5 – Labeling:

For Labeling, again there are two types of labels: Hazard Labels & Handling Labels.

First, Hazard Labels, which are square, measure 100 mm (about 4 inches) on each side, and must be applied on-point (in a diamond configuration), identify the primary hazard class or division (and, if applicable, any secondary hazards).  Also, an icon indicative of the nature of the risk appears in the upper quadrant of hazard labels.  According to DOT Chart 16 (effective through 2021), Hazardous Materials Markings, Labeling and Placarding Guide, there are a total of 27 colored hazard labels representing Classes 1 – 9, including the various divisions within many of these classes.

Most of these hazard labels correspond identically with the international hazard labels found in IATA and IMDG – with several minor exceptions.  For example, the DOT version of the Class 9, Miscellaneous label allows for two versions: (1) with vertical stripes on the upper half and a horizontal line separating the label in the middle; (2) the same vertical stripes on the upper half with no horizontal line across the middle.  This second version is identical to the international Class 9 label and should be used when shipping outside the US.  Another variation in domestic labels can be seen with regard to poison/toxic materials (Division 2.3 & 6.1) with an inhalation hazard where the skull and crossbones icon in the upper quadrant is shown by the DOT version in white with a black background; the international version is all white with the icon in black.  Also, note that the word “poison” or “toxic” may be used according to DOT regulations in the US; however, internationally only the word “toxic” may be used.

Typically, these labels are printed with text (words) indicating the nature of the corresponding risk; however, this text is optional and labels may be used without any words.  Of course, labels must be of the correct size, design, color and must display the numeral for the corresponding class or division in the bottom corner as appropriate.  One exception to this rule applies to toxic materials with an inhalation hazard, where the words, “Inhalation Hazard,” must appear on the label for transport to, from, within or through the US.

Hazard labels must be applied to packagings such that they are located on the same surface and near the markings of the UN Number and Proper Shipping name.  It is also recommended (but not required) that they be applied near the name and address of the shipper and consignee as well.  All labels must be applied to packages such that they do not cover or block any required labels or markings and do not extend past the surface of the package to which they are applied (i.e., do not touch or wrap around corners of the package such that they appear on different faces).

Second, Handling Labels, which are rectangular, are seldom used alone, but most commonly used together with the hazard labels.  Please note that DOT Chart 16 refers to many “Handling Labels” as marking requirements, although these “marks” are of standard specifications and colors, which, of course, can be purchased on rolls with adhesive backing for application as labels.  Handling Labels include the following:

  1. Package Orientation Labels (which may be considered markings under DOT ground regulations): These are double arrows, with a horizontal line or bar beneath, and are red or black in color (the surrounding border or box is optional).  The Package Orientation Label is required on two opposite sides of combination packagings containing liquid dangerous goods (i.e., single packagings, such as drums and jerricans, containing liquids do not require the Package Orientation Labels).
  2. Cargo Aircraft Only (CAO) Label: These are used on air packages which are not allowed on passenger (PAX) carrying aircraft and must be applied to the same surface and next to the hazard label.
  3. Keep Away From Heat (KAH) Label: This label is only required on packages when noted by special provision for materials that contain self-reactive substances in Division 4.1 and Division 5.2, Organic Peroxides (i.e., see IATA Special Provision A20).
  4. Note: When the Keep Away From Heat Label is used, the statement: “Store out of direct sunlight and away from all sources of heat,” is typically required to be shown on the shipping paper (shipper’s declaration, DGD, transport document, etc.).
  5. Magnetized Material Label (air only): Required on packages shipped by air with a magnetic field strength causing a compass deflection of more than 2 degrees at a distance of 2.1 m but not more than 2 degrees at a distance of 4.6 m (equivalent to 0.418 A/m or 0.00525 Gauss measured at a distance of 4.6 m).
  6. Marine Pollutant (dead fish) Label: This label is used on some aquatic environmental hazards or “Marine Pollutants” identified in the IMDG.

We hope you enjoyed this article and find this information useful.  Please feel free to bookmark it in your browser and recommend it to others who may benefit.

Finally, just as a reminder, this article is entitled, “The DG Shipping Process – Part 3: Marking & Labeling (Step 4 & 5 of 7).”

Please watch for “The DG Shipping Process – Part 4 – Documentation (Step 6 of 7)” – coming soon!

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