Preparing for the 2027 IATA Dangerous Goods Regulations: Section 3 and Section 4 Changes

By Dave Brennan

From 1 January 2027, the 68th edition of the IATA Dangerous Goods Regulations will become the industry reference document used for the transport of dangerous goods by air.

This article continues the review of changes adopted into the 2027 IATA Dangerous Goods Regulations and focuses on Section 3, Classification, and Section 4, Identification. Subsequent articles will address the remaining sections of the IATA Dangerous Goods Regulations and explain what the changes mean for different entities in the air cargo supply chain.

Section 3: Classification

Section 3 sets out the classification criteria that apply to dangerous goods in each of the nine classes. The classification criteria in the IATA Dangerous Goods Regulations are aligned with the United Nations Model Regulations to support consistency across all modes of transport.

The 2027 changes include updates affecting explosives, aerosols, toxic and infectious substances, corrosives, lithium batteries, sodium ion batteries and articles containing dangerous goods.

Class 1 Explosives

Classification of Explosives

The note under paragraph 3.1.5.4 has been amended to include a new sentence addressing explosives that are repacked for subsequent distribution:

“Consequently, if the explosives are repacked for subsequent distribution, the shipper will need to verify that the proposed packaging is permitted by the original classification or re apply the classification procedure prescribed in this chapter.”

In addition, a new paragraph 3.1.5.5 has been added, with the existing paragraph 3.1.5.5 renumbered as paragraph 3.1.5.6. The new paragraph states:

“Prior to transport, the explosive classification must have been conducted, approved or accepted by an appropriate national authority.”

These changes were added by the ICAO Dangerous Goods Panel following discussions over two previous meetings. The intent is to clarify the role manufacturers and national authorities play in the classification of explosives.

For industry, the practical message is that repacking explosives for later distribution is not simply a packaging decision. The shipper must ensure the proposed packaging remains permitted under the original classification, or the classification procedure must be applied again.

Class 2 Gases

Aerosols or Aerosol Dispensers

The provisions for the classification of aerosols in paragraph 3.2.5.2 have been revised.

An aerosol must now be assigned a subsidiary hazard of Division 6.1 or Class 8 where the contents, other than the propellant of aerosol dispensers, are classified as:

1. Division 6.1, packing groups II or III.
2. Class 8, packing groups II or III.

Aerosols are forbidden for transport where the contents meet the classification criteria of:

1. Class 1, Explosives.
2. Liquid desensitized explosives of Class 3.
3. Self reactive substances and solid desensitized explosives of Division 4.1.
4. Division 4.2, Substances liable to spontaneous combustion.
5. Division 4.3, Substances which, in contact with water, emit flammable gases.
6. Division 5.2, Organic peroxides.
7. Division 6.1, packing group I.
8. Division 6.2, Infectious substances.
9. Class 7, Radioactive material.
10. Class 8, packing group I.

The provisions for flammable aerosols in paragraph 3.2.5.3 have also been revised. The calorific heats of combustion may now be determined by reference to published scientific literature, through calculation, or by using suitable calorimetric test methods.

These changes reinforce the importance of assessing the actual contents of aerosol dispensers, not only the aerosol format or propellant.

Class 6 Toxic and Infectious Substances

Forbidden Toxic Substances

Note 2 under Table 3.6.A has been revised so that it also applies to mixtures. The reference to paragraph 3.8.2.3 has also been revised to include consideration of the requirements in paragraph 3.10.2(e).

Classification of Infectious Substances

The provisions for the classification of infectious substances have been revised to more clearly specify that infectious substances are divided into Category A and Category B.

Paragraph 3.6.2.2.2.1, subparagraphs (a) and (b), and the notes under subparagraph (b), have been changed into numbered paragraphs. This change recognises that the notes contain regulatory text rather than guidance, which is the normal purpose of a note.

To better address emerging international health situations, and to provide for a more flexible and dynamic indicative list of Category A infectious substances, the United Nations Subcommittee supported an amendment proposed by the World Health Organization and the expert from Canada.

A new sentence has been added to what was Note 2:

“To address emerging health situations, more up to date information on the applicable categories can be obtained from human and animal health inter governmental organizations and national authorities.”

This change reflects the need for classification provisions to remain responsive to emerging health risks and authoritative public health advice.

Exceptions for Used Medical Devices

Paragraph 3.6.2.2.3.9.3, which limits the exception from the Regulations for used medical devices where the medical device is contaminated with or contains other dangerous goods meeting another hazard class, has been revised.

The revised paragraph permits used medical devices to contain or be packed with lithium cells or batteries, or sodium ion cells or batteries.

A new paragraph 3.6.2.2.3.9.4 has also been added. It requires that when used medical devices and equipment contain or are packed with lithium cells or batteries, or sodium ion cells or batteries, the relevant entry of the Dangerous Goods List in Section 4.2 must be used and all applicable provisions of the Regulations apply.

For operators and acceptance personnel, this is an important distinction. The presence of lithium or sodium ion cells or batteries does not remove the need to apply the relevant Dangerous Goods List entry and associated requirements.

Class 8 Corrosives

General Classification Provisions

Paragraph 3.8.2.3 has been revised to also include consideration of the requirements in paragraph 3.10.2(e), as well as paragraph 3.6.1.4, Note 2.

This aligns the classification provisions for corrosives with the related provisions for forbidden toxic substances and relevant mixture considerations.

Class 9 Miscellaneous Dangerous Substances and Articles, Including Environmentally Hazardous Substances

Lithium Batteries

Paragraph 3.9.2.6.1 has been revised to delete the specific reference to lithium cells and batteries being assigned to UN 3090, UN 3091, UN 3480 or UN 3481, as applicable.

Instead, the sentence has been revised to read:

“Cells and batteries, cells and batteries contained in articles, engines, equipment or vehicles, or cells and batteries packed with equipment, containing lithium in any form may be transported under the appropriate entry, provided:”

This change was made because entries applying to lithium cells or batteries now include UN 3536, Lithium batteries installed in cargo transport unit, and UN 3556, Vehicle, lithium ion battery powered.

A new Note 2 has also been added under paragraph 3.9.2.6.1(a) to address lithium batteries that may be repaired or refurbished. The note states:

“A battery with a change resulting from treatment, such as repairing, refurbishing, or remanufacturing in accordance with 38.3.2.2(c) of the UN Manual of Tests and Criteria may be considered to differ from a tested type.”

A new subparagraph (h) has also been added to address hybrid batteries that contain both lithium ion cells and sodium ion cells.

These changes are important because lithium battery classification is increasingly affected by product design, installation context, repair or refurbishment status, and the emergence of hybrid battery technologies.

Sodium Ion Batteries

Paragraph 3.9.2.7.1 has been revised to delete the specific reference to sodium ion cells and batteries being assigned to UN 3551 or UN 3552, as applicable.

Instead, the sentence has been revised to refer to articles, engines, equipment or vehicles, or cells and batteries packed with equipment.

This reflects the expanding range of sodium ion battery applications and supports alignment with the broader battery related changes in the Regulations.

Articles Containing Dangerous Goods, n.o.s.

Paragraph 3.12.2 has been revised to specifically refer to lithium metal and lithium ion cells and batteries.

The reference to production runs of not more than 100 cells or batteries has also been clarified to refer to annual production runs.

This change provides more specific wording for articles containing dangerous goods, particularly where lithium batteries are involved.

Section 4: Identification

Section 4 deals with the selection of the proper shipping name assigned to dangerous goods, the Dangerous Goods List, and the special provisions that apply.

The changes to Section 4 include additions, deletions and amendments to entries in the Dangerous Goods List, as well as additions, amendments and deletions to special provisions.

List of Dangerous Goods

The changes to entries in the Dangerous Goods List are based on changes agreed by the United Nations Committee of Experts and adopted into the 24th revised edition of the United Nations Model Regulations.

The changes include the following:

1. UN 1727, Ammonium hydrogendifluoride, solid, has been assigned a Division 6.1 subsidiary hazard. The packing instructions and permitted net quantity are unchanged.
2. UN 2348, Butyl acrylates, stabilized, which is currently assigned only Packing Group III, has been revised to now include both Packing Group II and Packing Group III.
3. UN 2021, Chlorophenols, liquid in Packing Group III, has been revised to become Chlorophenols, toxic, liquid, n.o.s.
4. Two new entries have been added: UN 3561, Chlorophenols, corrosive, toxic, solid, n.o.s., 8 (6.1), Packing Group II. UN 3562, Chlorophenols, corrosive, solid, n.o.s., 8, Packing Group II.
5. UN 2020, Chlorophenols, solid in Packing Group III, has been revised to become Chlorophenols, toxic, solid, n.o.s.
6. UN 2372, 1,2 Di(dimethylamino) ethane, has been assigned Division 6.1 and Class 8 subsidiary hazards. As a result, the packing instructions and net quantities have been revised to Y340, 0.5 L, 352, 1 L, and 363, 5 L.
7. UN 1040, Ethylene oxide and Ethylene oxide with nitrogen, and UN 3300, Ethylene oxide and carbon dioxide mixture, which are classified in Division 2.3 with a Division 2.1 subsidiary hazard, now also have a Class 8 subsidiary hazard.
8. UN 1041, Ethylene oxide and carbon dioxide mixture, which is classified in Division 2.1, has been assigned a Class 8 subsidiary hazard.
9. UN 2941, Fluoroanilines in Division 6.1, has been deleted. The cross references 2,4 Difluoroaniline, 2 Fluoroaniline, 4 Fluoroaniline, o Fluoroaniline and p Fluoroaniline, which referred to UN 2941, now refer respectively to UN 2810, Toxic liquid, organic, n.o.s., UN 1992, Flammable liquid, toxic, n.o.s., UN 3267, Corrosive liquid, basic, organic, n.o.s., UN 1992, Flammable liquid, toxic, n.o.s., and UN 3267, Corrosive liquid, basic, organic, n.o.s.
10. The entries UN 2857 and UN 3358, which currently have the proper shipping name Refrigerating machines, have been revised to also apply to Heating machines.
11. UN 3536, Lithium batteries installed in cargo transport unit, lithium ion batteries or lithium metal batteries, has been revised to become UN 3536, Lithium ion batteries installed in cargo transport unit.
12. A new entry has been added: UN 3563, Lithium metal batteries installed in cargo transport unit.
13. A new entry has also been added: UN 3564, Sodium ion batteries installed in cargo transport unit.
14. UN 2862, Vanadium pentoxide non fused form in Packing Group III, has been revised to become UN 2862, Vanadium pentoxide non fused form, containing less than 10% respirable particles in Packing Group III. A new entry has also been added: UN 2862, Vanadium pentoxide non fused form, containing 10% or more respirable particles in Packing Group II.

These amendments demonstrate how identification changes can affect more than the wording of a proper shipping name. They can also affect subsidiary hazards, packing groups, packing instructions, permitted quantities and the selection of the correct entry.

Special Provisions

The revisions to special provisions include changes adopted directly from the 24th revised edition of the United Nations Model Regulations, as well as air transport specific changes adopted by the ICAO Dangerous Goods Panel.

The changes include the following:

1. A26 and A103 have been revised to include reference to heating machines, aligning with the revised proper shipping names assigned to UN 2857 and UN 3358.
2. The wording of A88 has been revised to correct a misalignment between the wording in paragraph 3.12.2 and A88.
3. A107, which is assigned to UN 3363, Dangerous goods in apparatus, articles or machinery, has been revised. It now permits such apparatus, articles or machinery to also contain lithium cells or batteries that meet the requirements in Section II of Packing Instruction 967 or Packing Instruction 970, or sodium ion cells or batteries that meet the requirements in Section II of Packing Instruction 978. A corresponding change has also been made to Packing Instruction 962.
4. A115, which is assigned to UN 3268, Safety devices, has been revised to permit the use of UN 3268 for safety devices of Class 9 transported for installation in UN 2990, Life saving appliances.

The following new special provisions have also been added.

A235: Hybrid Lithium Ion and Sodium Ion Batteries

A235 has been assigned against the entries for lithium ion batteries, UN 3480 and UN 3481, and sodium ion batteries, UN 3551 and UN 3552.

It identifies that hybrid batteries containing both lithium ion cells and sodium ion cells must be assigned to UN 3480 or UN 3481, as appropriate.

A236: MRI Scanners

A236 has been assigned against UN 3538, Articles containing non flammable, non toxic gas, n.o.s.

The new special provision addresses magnetic resonance imaging scanners:

“Articles transported under this entry include magnetic resonance imaging (MRI) scanners containing non flammable, non toxic gas. The non flammable, non toxic gas must be contained within MRI scanner components. The MRI scanners must be designed and constructed to contain the gas and preclude the risk of bursting or cracking of the gas retaining components during normal conditions of transport. MRI scanners are not subject to these Regulations if they contain less than 12 kg of gas in Division 2.2.”

A237: LPG Containing Dimethyl Ether

A237 has been assigned against UN 1965, Hydrocarbon gas mixture, liquefied, n.o.s., and UN 1075, Petroleum gases, liquefied.

It specifies that the substances may contain up to 12% by mass of dimethyl ether. This special provision was adopted by the United Nations Subcommittee to permit liquefied petroleum gas, LPG, to contain a blend that includes molecules of bio, renewable or recycled origin.

A238: Liquid Organic Hydrogen Carriers

A238 has been assigned against UN 3082, Environmentally hazardous substance, liquid, n.o.s.

This new special provision permits the transport of hydrogen where the hydrogen molecules are chemically bound to liquid organic hydrogen carriers, known as LOHC.

The text adopted by the United Nations Subcommittee for the special provision is as follows:

“Liquid organic hydrogen carriers (LOHC) based on substances classified under this entry with physically dissolved hydrogen may only be transported under this entry when the content of physically dissolved hydrogen does not exceed the limit of 0.5 L(H2)/kg (LOHC).”

What This Means for Industry

The Section 3 and Section 4 changes require close attention because classification and identification sit at the beginning of the dangerous goods compliance process.

If the classification is wrong, or the proper shipping name, UN number, packing group, subsidiary hazard or special provision is missed, the error can flow through the entire shipment. That can affect the Shipper’s Declaration, package selection, marks, labels, acceptance checks, system data, training material and operational decision making.

For shippers, forwarders, operators and ground handlers, these changes should be reviewed before the 2027 edition takes effect. Particular attention should be given to battery powered articles, repaired or refurbished batteries, hybrid battery technologies, infectious substances, aerosols and entries where subsidiary hazards or packing groups have changed.

Final Reflection

The 2027 changes to Section 3 and Section 4 reinforce a familiar but important principle in dangerous goods transport: compliance begins with correct classification and identification.

These amendments are detailed, but they are not minor. They affect how substances and articles are named, classified, assigned, packed and accepted for air transport.

Businesses preparing for the 68th edition of the IATA Dangerous Goods Regulations should treat these changes as a data and procedure readiness issue, not only as a regulatory update. Master data, training content, acceptance checks, templates and system logic will all need to be reviewed so that the correct classification and identification decisions are made before a consignment enters the air cargo system.