Dangerous Goods Questions and Answers: Test Your Knowledge

8 – 57 Questions 12 min

This quiz drills the IATA Dangerous Goods Regulations (DGR), aligned to ICAO Doc 9284, across classification, packing instructions, labels, and the Shipper’s Declaration for air transport. In the U.S., DOT/PHMSA HMR and FAA oversight can turn a paperwork slip into a rejected shipment, reportable incident, or audit finding. Civil penalties can exceed $100,000 per violation.

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1When preparing a dangerous goods shipment by air, what is the best starting point for classification?

2Packing Group I represents the highest level of danger for substances that are assigned a packing group.

True / False

3Orientation arrows are optional if the package has “This Way Up” text printed on it.

True / False

4A shipper wants to describe a chemical as “lab solvent” on the Shipper’s Declaration. What is the correct approach?

5During a pre-acceptance check, which mismatch is most likely to trigger a carrier rejection?

6A substance is assigned Packing Group I, but the shipper uses packaging marked for Packing Group II only. What is the issue?

7When are orientation arrows most commonly required on a dangerous goods package?

8A UN entry lists a subsidiary risk in addition to the primary hazard. What must the label set include?

9You are classifying a product for air shipment under IATA DGR. Select all that apply.

Select all that apply

10A compressed gas is identified as flammable (not toxic). Which division applies under Class 2?

11A package is placed in shrink wrap as an overpack and some marks/labels are no longer visible. Select all that apply.

Select all that apply

12Which IATA hazard class is used for corrosive substances?

13A shipment meets the cargo aircraft quantity limit but exceeds the passenger aircraft limit for the same UN entry. What is the correct action?

14A shipment is tendered with packages correctly marked and labeled, but the Shipper’s Declaration has inconsistent quantities and missing required information. What is the most likely outcome?

15In IATA’s hazard class system, lithium batteries most commonly fall under which class for transport purposes?

16Arrange the recommended workflow for identifying and classifying a dangerous good before packing it (first to last).

Put in order

1Identify the substance or article

2Confirm the primary class/division and any subsidiary risk

3Confirm the packing group (if assigned)

4Check special provisions that affect requirements

5Find the UN number and Proper Shipping Name (PSN)

6Select the applicable packing instruction

17You are reviewing a dangerous goods shipment for common “consistency” failures. Select all that apply.

Select all that apply

18Arrange the steps to determine and apply the correct label set for a dangerous goods package (first to last).

Put in order

1Determine any required handling labels/marks (e.g., CAO, arrows, overpack)

2Select the correct labels (primary + subsidiary + handling)

3Affix labels in the correct orientation/visibility requirements

4Confirm the UN entry’s primary class/division

5Check the UN entry for any subsidiary risk

6Perform a final cross-check against the UN entry and documents

19Arrange the best-practice steps for preparing multiple dangerous goods packages inside a single overpack for air transport (first to last).

Put in order

1Build the overpack without obscuring required marks/labels where possible

2Apply the “OVERPACK” marking on the outside

3Ensure documentation reflects the correct package counts and any overpack notation

4Check compatibility/segregation requirements for packages placed together

5If marks/labels are obscured, reproduce them on the outside

6Verify each inner package is fully compliant on its own

20For liquids shipped in combination packagings by air, which checks are typically critical? Select all that apply.

Select all that apply

21You are investigating why a shipment was repeatedly rejected for “classification errors.” Select all that apply as high-probability root causes.

Select all that apply

22Arrange a practical line-by-line reconciliation of a Shipper’s Declaration entry (top to bottom) before tendering.

Put in order

1Quantity and number/type of packages

2Packing group (if assigned)

3UN number and Proper Shipping Name

4Packing instruction reference

5Any required additional handling information (e.g., CAO wording/notes)

6Class/division and any subsidiary risk

23A lab ships non-dangerous biological samples packed with dry ice. What is typically required for the dry ice component?

24Two products share the same UN number, but one is shipped as a liquid and the other as a solid. What should the shipper do before choosing a packing instruction?

Disclaimer

This quiz is for educational and training purposes only. It does not constitute professional certification or legal compliance verification.

Frequent IATA Dangerous Goods Errors That Trigger Rejections and Findings

Most dangerous goods noncompliances are avoidable process failures: the UN entry is right, but the shipper’s classification, packaging, marks/labels, and documentation don’t match it exactly. These are the mistakes that most often show up at operator acceptance checks and during regulator reviews.

Classification and identification breakdowns

Starting from a trade name or SDS headline instead of the UN entry. Prevention: confirm Proper Shipping Name (PSN), hazard class/division, any subsidiary risk, and Packing Group (if assigned) from the regulatory list—not the product label.
Forgetting subsidiary risks or special provisions. Prevention: treat subsidiary risk labels and special provisions as “must-do” items that can change labels, quantity limits, or packaging details.
Misapplying lithium battery categories. Prevention: separate decisions for UN 3480 vs UN 3481, “contained in equipment” vs “packed with equipment,” and the section/PI requirements before you touch packaging.

Packing/quantity mistakes

Choosing the wrong packing instruction or packing option. Prevention: select PI only after confirming form (solid/liquid), PG, and whether passenger aircraft is allowed or Cargo Aircraft Only applies.
Quantity math errors (net vs gross; inner vs outer limits). Prevention: write down inner quantity, number of inners, and total net quantity per package; reconcile against the PI limits before closing the box.
Performance packaging mismatch. Prevention: verify the UN specification marking on the outer packaging supports the assigned PG and physical form.

Marks, labels, and paperwork traps

Hidden marks/labels under shrink wrap or an overpack. Prevention: if any required marks/labels aren’t visible, reproduce them on the outside and apply the OVERPACK marking when required.
Orientation arrows missing for liquids. Prevention: treat arrows as a mandatory marking for applicable combination packagings—don’t rely on “this carton ships upright.”
Shipper’s Declaration inconsistencies. Prevention: do a line-by-line match: UN number, PSN, class/division, subsidiary risk, PG, PI, package type/count, and net quantity—then confirm units and signatory details.

Desk-Side IATA DGR Shipment Build Checklist (Print/PDF)

Printable note: You can print this section or save it as a PDF and use it as a pre-tender checklist for each air dangerous goods consignment.

Step 1 — Identify and classify (in this order)

Identify the substance/article (composition, concentration, physical state, battery chemistry, aerosol type, etc.).
Assign UN number + Proper Shipping Name (PSN) from the list/entry you are shipping under.
Confirm primary hazard class/division and subsidiary risk(s) (if any).
Confirm Packing Group (I/II/III) when assigned.
Check special provisions that add/modify packaging, marking, or documentation.

Step 2 — Pick the correct packing instruction (PI) and limits

Verify aircraft limitation: allowed on passenger aircraft vs Cargo Aircraft Only (CAO).
Confirm packaging type: combination vs single packaging; required absorbent/cushioning for liquids; closure torque/sequence per manufacturer instructions.
Do the quantity math twice: inner quantity × number of inners = total net; compare to PI limits and any operator/state restrictions.

Step 3 — Build the outside of the package (marks/labels you must reconcile)

Identification marking: UN number + PSN (as required) and any required technical name/additional text per the entry.
Hazard labels: primary label + any subsidiary risk labels; remove/cover irrelevant legacy labels.
Handling labels/marks (as applicable): CAO label, lithium battery mark, dry ice mark/label, “overpack” marking, and any required package orientation arrows.
Overpack control: if you wrap multiple packages, ensure required marks/labels remain visible—or repeat them on the outside and mark OVERPACK.

Step 4 — Documentation cross-check (before tender)

Shipper’s Declaration (when required): confirm the exact sequence of description elements, packing instruction, net quantity, and packing group; sign with the correct certification statement and name/title.
Air waybill entries: ensure dangerous goods information matches the package and declaration (and include any required statements for items shipped under specific provisions, e.g., dry ice shipments when applicable).
Recordkeeping: retain training and shipment records per your company SOP and applicable regulatory retention requirements.

The 9 hazard classes (memory anchor)

Class 1 Explosives
Class 2 Gases
Class 3 Flammable liquids
Class 4 Flammable solids / spontaneous combustion / dangerous when wet
Class 5 Oxidizers / organic peroxides
Class 6 Toxic / infectious substances
Class 7 Radioactive material
Class 8 Corrosives
Class 9 Miscellaneous (including several battery and environmentally hazardous entries)

Air Shipper Decision Drills Based on IATA DGR Acceptance Checks

Use these short drills to practice the exact judgment calls that typically decide pass/fail at operator acceptance and in internal audits. For each scenario, state the UN number/PSN, allowed aircraft type, packing instruction logic, required marks/labels, and whether a Shipper’s Declaration is required.

Flammable liquid sample to a lab.
You’re shipping a solvent mixture with a confirmed UN entry as a Class 3, Packing Group II liquid in a combination package with glass inners. What makes orientation arrows mandatory, and what common documentation field mismatches would cause a rejection?
Dry ice used as refrigerant.
A package contains non-dangerous goods with UN 1845 Dry ice as coolant. What must appear on the package regarding net weight, and what information must be carried on the air waybill? Under the usual dry ice packing instruction, is a Shipper’s Declaration typically required?
Lithium ion batteries shipped alone.
You are offered lithium ion batteries as UN 3480. What additional air-transport conditions (for example, state-of-charge control) must your process verify before packing, and what marks/labels would be different if the same cells were UN 3481 packed with equipment?
Aerosols for maintenance.
Aerosol cans are tendered as “consumer aerosols.” What is the risk of relying on the retail description, and which two checks determine whether passenger aircraft carriage is permitted (authorization + quantity limitation)?
Overpack with mixed packages.
You shrink-wrap two fully compliant DG packages onto one skid and call it an overpack. Which marks/labels must remain visible or be repeated, and when does the OVERPACK marking become mandatory?
UN 3373 with refrigeration.
Category B biological substance (UN 3373) is shipped with dry ice. What packaging system governs the biological material, and how do you prevent the dry ice requirements from being “forgotten” during the medical packing workflow?
Documentation reconciliation drill.
A Shipper’s Declaration shows the correct UN number and PSN, but the packing instruction and net quantity do not match the package configuration. What is your stop-ship checklist to reconcile: package count, inner/outer quantities, and units?

Authoritative Regulations and Guidance for IATA/ICAO Dangerous Goods by Air

IATA Dangerous Goods Regulations (DGR) — The industry manual used by airlines and shippers for classification, packing instructions, marking/labeling, and documentation for air transport.
ICAO Technical Instructions (Doc 9284) portal — ICAO’s Dangerous Goods Technical Instructions framework that underpins international air DG requirements.
FAA SafeCargo: How to Ship Dangerous Goods — FAA shipper-focused guidance on shipper responsibilities, packing groups, and key compliance concepts for hazmat by air.
PHMSA Lithium Battery Guide for Shippers — Mode-agnostic compliance guide covering packaging, marking, and documentation fundamentals for lithium cells and batteries under the HMR.
eCFR: 49 CFR Subchapter C (Hazardous Materials Regulations) — The current U.S. DOT hazardous materials regulatory structure, including Parts 171–180 (with Part 175 covering carriage by aircraft).

IATA Dangerous Goods Regulations (DGR) FAQ for U.S. Shippers and Aviation Teams

How do IATA DGR and U.S. DOT/PHMSA HMR relate when I’m shipping by air?

IATA DGR is the airline-focused industry manual aligned to ICAO Technical Instructions, while the U.S. Hazardous Materials Regulations (HMR) are the legally enforceable baseline for shipments to, from, or within the United States (with FAA responsible for air-transport compliance). In practice, you must meet IATA/ICAO requirements and any U.S. HMR conditions that apply to your shipment and role.

When is the Cargo Aircraft Only (CAO) label required, and what does it change operationally?

The CAO label is required when the dangerous goods entry/quantity is authorized only on cargo aircraft. Operationally, this affects routing options, carrier acceptance, and stowage/handling controls; it also drives a “hard stop” at acceptance if the package is presented for passenger aircraft movement.

Do I always need a Shipper’s Declaration for dry ice (UN 1845) or lithium batteries?

No. Some items have documentation relief under specific packing instructions/sections, while still requiring strict marking, labeling, and air waybill statements. Treat “no declaration” as a regulated condition: you still must prove the package meets the applicable instruction (including net quantity limits and correct marks) and any operator variation.

What’s the most reliable way to prevent a UN number/PSN mismatch on paperwork?

Use a single source-of-truth workflow: start from the UN entry, then copy the Proper Shipping Name, class/division, subsidiary risk, and packing group into your shipping system. Before tender, do a three-way reconciliation between (1) the package marks/labels, (2) the Shipper’s Declaration (if required), and (3) the air waybill entries.

What does “overpack” mean in IATA DGR terms, and why does it cause so many rejections?

An overpack is an enclosure used to consolidate packages (e.g., shrink wrap, outer crate, or stretch wrap) without changing the inner packages. Rejections happen when required marks/labels become hidden or unreadable, or when the overpack is missing the required OVERPACK marking. Your acceptance check should explicitly ask: “Are all required marks/labels visible on the outside of the overpack?”

My job spans air and ground hazmat—what should I study next?

If you need deeper aviation-specific practice (operator acceptance logic, air waybill/declaration alignment, and common rejection points), use the Dangerous Goods Licence Test Questions. If your responsibilities include DOT roadside/terminal compliance and broader HMR duties, the DOT Inspection Certification Practice Test pairs well with air DG training.

Five Practical Skills This IATA DGR Quiz Should Improve

Start from the UN entry, not the product name: always anchor your work to UN number + Proper Shipping Name, then verify class/division, subsidiary risk, and Packing Group before selecting packaging.
Prove the packing instruction with numbers: reconcile inner quantity, number of inners, and total net quantity per package against the packing instruction limits before closing the package.
Treat marks/labels as a system check: the correct label set is determined by primary hazard + subsidiary risk + any handling label (e.g., CAO), not by what you used last time.
Overpacks must not hide compliance: if shrink wrap or an outer enclosure obscures marks/labels, repeat them on the outside and apply the OVERPACK marking when required.
Do a three-way document match: package ↔ Shipper’s Declaration ↔ air waybill must agree on UN/PSN, class, PG, packing instruction, package count, and net quantities, or the shipment is effectively noncompliant.

Dangerous Goods by Air Glossary (IATA/ICAO Terms You Must Use Precisely)

Proper Shipping Name (PSN): The standardized regulatory name that must be used for the dangerous goods description. Example: use the PSN associated with a UN entry rather than “lab solvent.”
UN Number: A four-digit identifier assigned to a dangerous goods entry. Example: “UN 1845” identifies dry ice for transport descriptions and marking.
Packing Group (PG): A severity grouping (I high, II medium, III low) used to determine packaging performance and limits for many entries. Example: a PG II assignment cannot be shipped in packaging only rated for PG III.
Subsidiary Risk: An additional hazard associated with the material that can require extra hazard labels. Example: a flammable liquid with a corrosive subsidiary risk needs both the primary and subsidiary labels as required by the entry.
Packing Instruction (PI): The set of packaging options, limits, and conditions tied to an entry for air transport. Example: the PI determines whether a combination package is allowed and the maximum net quantity per package.
Cargo Aircraft Only (CAO): A limitation indicating the package is forbidden on passenger aircraft and may only move on cargo aircraft under specified conditions. Example: CAO affects routing and requires the CAO handling label when applicable.
Overpack: An enclosure used to consolidate one or more packages for convenience in handling without changing the inner packages. Example: shrink-wrapping two DG packages onto a skid can create an overpack that must display visible required marks/labels (or have them repeated).
Shipper’s Declaration for Dangerous Goods: A formal certification document required for many (but not all) air DG shipments, with prescribed description order and shipper attestation. Example: a correct UN/PSN entry can still be rejected if the declaration’s net quantity or packing instruction doesn’t match the package.
Limited Quantity / Excepted Quantity: Regulated relief frameworks that may reduce requirements when strict conditions are met. Example: you may still need specific marks and air waybill statements even when a full Shipper’s Declaration is not required.