DGSA track
Module 3 of 7

Packaging, marking, labelling & placarding

Approved packagings and UN marks, package labels, and vehicle/container placarding the DGSA must verify.

ADR 2025 · 4.1ADR 2025 · 6.1ADR 2025 · 5.2ADR 2025 · 5.3
Exam preparation & CPD only. DGMind does not examine or certify DGSAs — the legal certificate is issued by the SQA after you pass its exams.
Draft content — pending review by a qualified DGSA

Lessons

Cyan · Lesson

Approved packagings and the UN mark

20s ADR 2025 · 4.1.1 / 6.1.3

Dangerous goods must travel in packaging that meets a tested UN design type and matches the packing instruction in column 8 of Table A. The packaging carries a UN packaging mark (the circled-u or 'un' symbol followed by a code) showing the type, the materials, the packing group it is approved for and the year/country of manufacture. The DGSA checks that the packing instruction is being followed and that the mark matches the goods' packing group.

Use the packing instruction (Pxxx) from Table A column 8.
Key points
  • UN packaging mark encodes type, material, packing group letter (X=I, Y=II, Z=III) and origin.
  • X-rated packaging covers PG I/II/III; Y covers II/III; Z covers III only.
  • Damaged or out-of-spec packaging must not be used.
ADR Citation
ADR 2025 · 4.1.1 / 6.1.3
Packagings must conform to a tested design type and bear the UN packaging mark of 6.1.3, used in accordance with the packing instructions referenced in Table A column 8 (Chapter 4.1).
Draft content, pending DGSA review. Verify against the cited clause before relying on it.
Cyan · Lesson

Package labels and vehicle placarding

15s Class 3 diamond Class 5.1 diamond Class 8 diamond (split) ADR 2025 · 5.2 / 5.3
ADR hazard class 3 — FlammableClass 3 diamond
ADR hazard subclass 5.1 — OxidiserClass 5.1 diamond
ADR hazard class 8 — CorrosiveClass 8 diamond (split)

Packages carry diamond hazard labels (symbol top, class number bottom) plus the UN number and any marks such as the orientation arrows or the environmentally-hazardous mark. The transport unit shows orange-coloured plates, and tanks/containers show enlarged placards. The DGSA's job is to verify the right labels and placards are present and that marking which no longer applies is removed — a common audit failing.

Package: diamond label(s) + UN number + relevant marks (5.2).
Key points
  • Transport unit: orange plates; tanks/bulk show HIN + UN number (5.3.2).
  • Tanks/containers: enlarged class placards (5.3.1).
  • Remove/cover marking that no longer applies — verify on audit.
ADR Citation
ADR 2025 · 5.2 / 5.3
Marking and labelling of packages (5.2) and placarding and orange-plate marking of vehicles, tanks and containers (5.3) identify the goods and their hazards for handlers and emergency services.
Draft content, pending DGSA review. Verify against the cited clause before relying on it.
Cyan · Lesson

Tank codes — reading column 12 of Table A

20s ADR 2025 · 3.2.1 / 4.3 / 6.8

For tank carriage the DGSA reads the tank code in column 12 of Table A and matches it to the tank's plate. A code like 'L4BN' tells you: 'L' = portable tank for liquids, the minimum design pressure ('4' = 4 bar), the type of opening ('B' = bottom-opening with specific valve arrangement), and the safety valve type ('N' = no safety valve). The portable-tank instruction (T-codes, e.g. T4, T7, T11) sits in column 10. The adviser does NOT need to design tanks — but must verify the tank approved for the goods is actually being used.

Column 12 = tank code (LGBF, L4BN etc.).
Key points
  • Column 10 = portable-tank / UN tank instruction (T-codes).
  • Verify the tank's data plate matches the column-10/12 requirement for the UN entry.
  • Wrong tank code = wrong containment; common enforcement finding on hired-in tankers.
ADR Citation
ADR 2025 · 3.2.1 / 4.3 / 6.8
Tank instructions in column 10/12 of Table A reference Chapters 4.3 (use) and 6.8 (construction) — the adviser verifies the tank plate matches the assigned code for the goods carried.
Draft content, pending DGSA review. Verify against the cited clause before relying on it.
Cyan · Lesson

Reading the segregation matrix without errors

25s ADR 2025 · 7.5.2.1

Most DGSA mistakes on segregation come from misreading the 7.5.2.1 table — particularly when one row has a footnote or when a label combination simply isn't shown. The right method: (1) identify EVERY label on each package (primary AND subsidiary), (2) take each pair in turn, (3) look up the cell at the intersection of the two label codes, (4) treat a blank cell as PROHIBITED until proven otherwise, (5) apply any footnoted condition before deciding 'permitted'. Subsidiary labels matter — a Class 8 with subsidiary 5.1 is read on both rows, and the most restrictive outcome wins.

List ALL labels per package (primary + subsidiary), not just the class number.
Key points
  • Take pairs one at a time; do not eyeball the whole truck.
  • Blank / not-shown cell = treat as PROHIBITED (fail-safe).
  • Subsidiary labels are read alongside primary; most restrictive outcome wins.
ADR Citation
ADR 2025 · 7.5.2.1
Packages bearing different danger labels shall not be loaded together unless mixed loading is permitted by the table in 7.5.2.1, which keys on the labels (including subsidiary labels).
Draft content, pending DGSA review. Verify against the cited clause before relying on it.

Practice questions (MCQ)

0 / 8 answered
  1. 1
    Which Table A column gives the packing instruction to use?
  2. 2
    On the UN packaging mark, the letter 'Y' means the packaging is approved for:
  3. 3
    What does the orange plate on a tanker normally display?
  4. 4
    A subsidiary risk label differs from the primary label in that it:
  5. 5
    On audit, the DGSA finds old placards left on an empty, cleaned vehicle. This is:
  6. 6
    The tank code on a UN portable tank lives in:
  7. 7
    A package carries Class 8 (primary) with a subsidiary 5.1 label. On the 7.5.2.1 matrix you must:
  8. 8
    An audit finds a label combination not shown in the 7.5.2.1 table. The DGSA's call is:
Practice quiz — pick an answer to see whether it's right and why.

Written-answer & case-study practice

The real DGSA exam is open-book short-answer plus a case study. These are self-study — draft your answer, then reveal the model answer to compare. Not auto-graded.

1
Short-answerSelf-study — model answer, not auto-graded

During a packaging audit you see PG II flammable liquid packed in drums marked with a 'Z' in the UN packaging code.

Your tasks
  1. State whether the packaging is suitable and why.
  2. Explain what the packing-group letters X/Y/Z mean.
  3. Recommend the corrective action.
2
Case studySelf-study — model answer, not auto-graded

EQUIPMENT AUDIT CASE STUDY. You are auditing a vehicle being loaded with packages of UN1830 (sulphuric acid, Class 8, PG II) and UN1170 (ethanol, Class 3, PG II) for a multi-drop route. Findings: (a) one drum of the acid has a UN packaging code ending 'Y2', the ethanol drums carry 'X1.4'; (b) the vehicle is showing orange plates with the old delivery's UN number still visible; (c) the diamond label on three acid drums is faded and the class number is unreadable; (d) the EX/II/EX/III vehicle equipment list is missing a wheel chock.

Your tasks
  1. Decide whether each packaging is acceptable.
  2. List each marking/placarding failing and cite the clause.
  3. State the immediate corrective actions and what you would record.
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