Dangerous Goods in Air Freight

Dangerous goods (also called hazardous materials or "hazmat") are substances and articles that pose a risk to health, safety, property, or the environment during air transport. The IATA Dangerous Goods Regulations (DGR) — currently in its 67th Edition (effective January 1, 2026) — is the globally recognized standard for classifying, packaging, marking, labeling, and documenting these shipments. Every airline requires compliance with the DGR as a condition of carriage.

The IATA DGR is based on the ICAO Technical Instructions for the Safe Transport of Dangerous Goods by Air, which in turn derives from the UN Recommendations on the Transport of Dangerous Goods (Model Regulations). This layered framework ensures consistency across all transport modes while imposing additional restrictions specific to the unique risks of air transport — cabin pressurization, temperature extremes, vibration, and the impossibility of stopping mid-flight.

Critical Compliance Area

Shipping undeclared or improperly packaged dangerous goods by air is a criminal offense in most jurisdictions. Fines can exceed $500,000, and incidents endanger aircraft, crew, and passengers. Always verify compliance before tendering hazmat shipments.

The Nine Hazard Classes

The UN classification system divides dangerous goods into nine hazard classes, several with subdivisions. Each class corresponds to a specific type of hazard and carries its own packaging, labeling, and handling requirements.

Class	Name	Divisions	Examples
1	Explosives	1.1–1.6	Ammunition, fireworks, detonators, flares
2	Gases	2.1 Flammable, 2.2 Non-flammable/non-toxic, 2.3 Toxic	Propane, CO₂, nitrogen, aerosols, fire extinguishers
3	Flammable Liquids	—	Paints, adhesives, perfumes, fuel, alcohols
4	Flammable Solids	4.1 Flammable solids, 4.2 Spontaneously combustible, 4.3 Dangerous when wet	Matches, magnesium, sodium, calcium carbide
5	Oxidizers & Organic Peroxides	5.1 Oxidizers, 5.2 Organic peroxides	Hydrogen peroxide, ammonium nitrate, bleach
6	Toxic & Infectious Substances	6.1 Toxic, 6.2 Infectious	Pesticides, cyanides, medical specimens, cultures
7	Radioactive Materials	I, II, III (transport index)	Medical isotopes, smoke detectors, density gauges
8	Corrosives	—	Batteries (acid), sulfuric acid, sodium hydroxide, mercury
9	Miscellaneous	—	Lithium batteries, dry ice, magnetized materials, vehicles

Packing Groups

Classes 3–6 and 8 are further classified into Packing Groups that indicate the degree of danger:

• Packing Group I — Great danger
• Packing Group II — Medium danger
• Packing Group III — Minor danger

The packing group determines the performance level required for UN-specification packaging.

Subsidiary Risks

Many substances present more than one hazard. A subsidiary risk (or secondary hazard) requires additional labeling. For example, a flammable liquid that is also toxic must carry both a Class 3 label and a Class 6.1 subsidiary risk label.

Packaging and Labeling Requirements

Proper packaging is the primary defense against dangerous goods incidents in air transport. The DGR mandates UN-specification packaging (also called Performance Oriented Packaging or POP) for most dangerous goods.

UN Packaging Standards

UN-specification packaging is tested to withstand the conditions of air transport:

Test	Purpose	Applies To
Drop test	Simulates handling impacts (1.2m for PG I, 1.0m for PG II, 0.8m for PG III)	All UN packaging
Stacking test	Simulates weight of stacked cargo	Drums, boxes, jerricans
Leakproofness test	Verifies liquid containers don't leak under pressure	Liquid packaging
Hydrostatic pressure test	Tests internal pressure resistance	Metal/plastic drums for liquids
Vibration test	Simulates transport vibration	Combination packaging

Each approved package bears a UN marking that encodes its specifications:

UN 4G/Y30/S/25/USA/+AA0001
│   │  │  │  │   │     └── Manufacturer code
│   │  │  │  │   └── Country of authorization
│   │  │  │  └── Year of manufacture
│   │  │  └── Solid (S) or Liquid (L)
│   │  └── Max gross weight (kg)
│   └── Packing group (X=I, Y=II, Z=III)
└── Packaging type (4G = fibreboard box)

Labeling Requirements

Every dangerous goods package must display:

1. Hazard class label(s) — diamond-shaped labels (minimum 100mm × 100mm) indicating primary and subsidiary hazards
2. UN number — preceded by "UN" (e.g., UN1203 for gasoline)
3. Proper Shipping Name — the standardized name from the DGR (e.g., "Flammable liquid, n.o.s.")
4. Handling labels — orientation arrows for liquids, "Cargo Aircraft Only" where applicable
5. Shipper and consignee information — name and address on the same surface as the hazard label

Overpack Marking

When multiple packages are placed inside an outer container (an overpack), the overpack must be marked with the word "OVERPACK" and display all labels and markings visible from the outside, unless the inner packages' markings are already visible.

The Shipper's Declaration for Dangerous Goods

The Shipper's Declaration for Dangerous Goods (DGD) is a mandatory document for most dangerous goods shipments by air. It certifies that the shipper has properly classified, packaged, marked, and labeled the shipment in accordance with the DGR.

Key Information on the DGD

The declaration must include:

• Shipper and consignee details
• Air waybill number
• Aircraft type restriction (Passenger & Cargo Aircraft, or Cargo Aircraft Only)
• UN number, Proper Shipping Name, hazard class, and packing group
• Quantity and type of packaging
• Packing instruction reference
• Authorization details (if special permission was granted)
• Signed certification by the shipper that the shipment complies with IATA DGR

Industry Practice

Many freight forwarders employ certified DG specialists who hold IATA DG Category 1 (shippers) or Category 6 (freight forwarders) certification. These professionals prepare and verify dangerous goods documentation, reducing the risk of rejection at acceptance.

Shipper and Carrier Responsibilities

Shipper Obligations

The shipper bears primary responsibility for dangerous goods compliance:

• Classify the substance correctly using DGR criteria
• Package in UN-specification packaging appropriate to the hazard
• Mark and label all packages with required information
• Complete documentation — Shipper's Declaration and AWB handling information
• Train personnel — anyone involved in preparing DG shipments must hold current IATA DG training
• Provide emergency information — 24-hour emergency contact for the shipment

Carrier Obligations

Airlines and their ground handling agents must:

• Perform acceptance checks — verify documentation completeness, inspect packages for damage and correct labeling, confirm quantities against the declaration
• Apply loading restrictions — segregation rules prevent incompatible classes from being loaded together; some items require specific aircraft positions
• Notify the pilot-in-command — the NOTOC (Notification to Captain) must list all dangerous goods aboard, their location, and emergency procedures
• Report incidents — any dangerous goods accident or incident must be reported to the relevant civil aviation authority

Restricted and Forbidden Articles

The DGR distinguishes three categories of restriction:

Category	Description	Examples
Forbidden on all aircraft	Cannot be transported by air under any circumstances	Explosives (Div. 1.1, 1.2, 1.3 except small quantities), toxic gases, infectious substances not in compliance
Forbidden on passenger aircraft	Allowed on cargo-only aircraft	Many Class 1 items, large lithium batteries, certain toxics and corrosives
Permitted with conditions	Allowed on both aircraft types with specific packaging/quantity limits	Small lithium batteries, dry ice (≤200 kg), aerosols, limited/excepted quantities

Special Provisions and Exemptions

• Limited Quantities — small amounts of certain dangerous goods in consumer-type packaging may ship with reduced requirements
• Excepted Quantities — very small amounts (milliliters/grams) may be exempt from most DGR requirements when properly packaged
• Operator Variations — individual airlines may impose stricter limits or refuse certain goods entirely (published as "Operator Variations" in the DGR)
• State Variations — countries may impose additional restrictions beyond ICAO standards

Lithium Batteries — A Special Focus

Lithium batteries (Class 9, UN3480/UN3481 for lithium-ion; UN3090/UN3091 for lithium metal) are the most frequently shipped dangerous good by air and the most common cause of DG-related incidents.

Key Regulations (2026 DGR, 67th Edition)

Configuration	Packing Instruction	Aircraft Restriction	State of Charge
Li-ion batteries alone (Section I)	PI 965	Cargo Aircraft Only	≤ 30% SOC
Li-ion batteries alone (Section II)	PI 965	Passenger & Cargo	≤ 30% SOC
Li-ion packed with equipment	PI 966	Passenger & Cargo	No restriction
Li-ion contained in equipment	PI 967	Passenger & Cargo	No restriction
Li-metal batteries alone	PI 968	Cargo Aircraft Only	N/A
Li-metal packed with equipment	PI 969	Passenger & Cargo	N/A
Li-metal contained in equipment	PI 970	Passenger & Cargo	N/A

2026 Update

Starting January 1, 2026, standalone lithium-ion batteries shipped under Section I (PI 965) and Section II must be offered at a state of charge not exceeding 30% of rated capacity, or an indicated battery capacity not exceeding 25%. This applies to all standalone battery shipments.

The BATTERY mark (introduced in the DGR 67th Edition) is now required on packages containing lithium batteries prepared under Section II of the applicable packing instruction, replacing the previous lithium battery handling label.

Training Requirements

The IATA DGR mandates that all personnel involved in the air transport of dangerous goods must receive initial and recurrent training (every 24 months). Training categories include:

Category	Personnel	Scope
1	Shippers/packers	Classification, packaging, marking, labeling, documentation
3	Operators handling DG	Acceptance, storage, loading procedures
6	Freight forwarders	Acceptance, storage, DGD verification
10	Security staff	Recognition of undeclared DG
12	Flight crew	Emergency procedures, NOTOC interpretation

Training must be specific to the individual's function and include both general awareness and function-specific components, with assessment to confirm competency.

Resources

Resource	Description	Link
IATA Dangerous Goods Regulations	The definitive manual for shipping hazardous materials by air (67th Edition, 2026)	iata.org/dgr
IATA Lithium Battery Guidance	Official guidance document for shipping lithium and sodium-ion batteries	iata.org/lithium-batteries
FAA Hazmat — How to Ship	U.S. FAA guide to packaging and shipping dangerous goods by air	faa.gov/hazmat
UN Transport of Dangerous Goods	The underlying UN Model Regulations that form the basis for IATA DGR	unece.org/transportdangerous-goods
TSA Cargo Screening Program	U.S. TSA requirements for screening air cargo, including dangerous goods	tsa.gov/cargo-screening

Related Topics

• Air Waybill — the AWB must include dangerous goods handling information and reference the Shipper's Declaration
• ULD Types — certain dangerous goods have specific ULD loading restrictions and segregation requirements
• Airport Operations — dangerous goods acceptance is a critical step in cargo terminal operations
• Import/Export Documentation — dangerous goods require additional customs and regulatory documentation