The United Nations Subcommittee of Experts on the Transport of Dangerous Goods (UNSCOE TDG) is holding their 66th Session June 30 through July 4, 2025 in Geneva, Switzerland. There are 36 formal and 70 informal papers submitted for discussion as of Day 5. This session is the first of four sessions during the 2025-2026 biennium.

All daily sessions are to be held formally (interpreted). Therefore, papers are to be reviewed as listed on the agenda (INF.2) and final decisions will be taken when appropriate.

This summary is provided to assist you in following the discussions of the papers and is not intended as a full summary of the document that was presented. Links to individual papers are provided to allow you to read the papers directly. Note that the Official report of the session will be made available by the UN Secretariat 3-4 weeks after the session concludes.

Day 5 – Discussion of Papers

2025/16 (China) + INF.69 (China) A revised proposal for punching holes as handles on the sides of 4G fibreboard box packagings – China provided a revised proposal to address holes in packaging by modifying the definition of a “box” in 1.2.1. They acknowledged COSTHA’s concern over use of the term “small” but stated that is existing text elsewhere in the regulations. COSTHA indicated they supported the proposal as drafted. The Subcommittee agreed to the proposal as drafted.

Energetics Working Group (EWG)

The EWG provided a report of the efforts from the week. The summary below includes only the conclusions from the EWG discussion. For the full report, please refer to the official report published as INF.70. The Chairman of the EWG thanked Dr. Josh Hoffman of IME for his support in drafting the EWG report.

2025/10 (SAAMI) Review of criteria for UN 0012 –

  • Conclusion: The EWG supported the development of greater understanding of how fragment impacts could lead to human harm e.g. by considering modifications to the testing approach in Appendix 9 of the MTC for sporting ammunition. However, caution was expressed by authorities about introducing a double standard for 1.4S criteria. There was mixed support for using the GHS definitions of low explosion hazard and the subcategory 2C classification criteria to clarify the Test 6 (d) criteria for hazardous effects, citing a lack of diagnostic testing for quantifying hazard event levels in GHS. Additionally, several competent authorities recommended that any approach should be consistent across 1.4S.

INF.47 (AEISG, IME on behalf of the IWG) UN Energetics Working Group, Intersessional Correspondence Group Test 8(d) – Update to SubCommittee of Experts on the Transport of Dangerous Goods –

  • Conclusion: After a thorough and helpful discussion, it was agreed that there is significantly more experience with ANEs than when the test was introduced over 20 years ago. It was recognized that there is doubt as to whether the 8(d) test is appropriate, given that its reproducibility has been questioned. Some participants voiced that, absent any other test, the test has value in discriminating between types of compositions and provides some confidence that ANEs will not react unduly quickly when heated in bulk when under confinement. The EWG encouraged the ICG to consider in more detail whether the 8(d) should be removed, retained as is, or if the criteria for testing need to be changed (i.e., testing durations) to determine suitability for transport in tanks. The material of the tank is an outstanding issue in need of more discussion. Differences in ANE formulation are suspected to play a role in test outcomes; however, it is unknown which formulation differences have the most significant effect, and these differences require further study. To progress its discussions further, the ICG should reconsider its Terms of Reference based on the EWG’s feedback and continue its work to provide a final report at the 68th session.

INF.25 (Cefic) Alternative packagings for the safe transport of small amounts of energetic samples according to special packing provision PP95 of Packing Instruction P520 –

  • Conclusion: The EWG supported the proposal but requested that the authors return with a formal proposal that takes into account the feedback regarding tolerances of foam density.

INF.42 (AEISG on behalf of the IWG) Battery Electric Vehicle use for Transport of Explosives – Progress of the IWG EV EX Subgroup –

  • Conclusion: The EWG concluded that amendment of the ADR to allow carriage of Class 1 materials on EX-categories of BEVs is appropriate and the EWG suggests that the IWG-EV prepares a proposal to WP.15 aligned with the requirements for FL category vehicles and supplemented with a requirement for tyre pressure and temperature monitoring systems. The issue of a Battery Master Switch was considered to be a separate issue for future discussion by interested parties.

2025/5 (SAAMI) UN 0338 and UN 0339 – Metal on metal contact between explosives and packaging –

  • Conclusion: After a thorough discussion of document ST/SG/AC.10/C.3/2025/5, the EWG agreed to recommend adopting the proposal in ST/SG/AC.10/C.3/2025/5 in paras. 8 and 9 as amended to assign PP100 to UN 0338 and 0339. See Annex II, Amendment 1.

2025/7 (COSTHA)+ INF.48 (COSTHA) Introduction of new entries for 1,4-BENZOQUINONE DIOXIME (QDO) –

  • Conclusion: The EWG was invited to provide any additional suggestions and comments on INF.48 to COSTHA. COSTHA was invited to take account of the comments raised during the meeting and the additional comments it receives in any revised proposal it chooses to submit.

2025/11 (SAAMI) + INF.5 (SAAMI) + INF.22 (Kingdom of the Netherlands) Dangerous Goods List and appendix B updates –

  • Conclusion: The EWG agreed this was useful work to improve the UNMR. SAAMI was encouraged to compare entries between DGL and glossary, suggest reductions in duplication, such as with MINES, and submit a refined proposal at a future meeting. The expert from the Kingdom of the Netherlands agreed to assist with this proposal.

2025/14 (SAAMI) + INF.40 (Germany) Thought starter on the Class 1 definition –

  • Conclusion: After a robust conversation, the EWG invited detailed comments regarding the questions in the paper to be sent to SAAMI. There was recognition that there are circumstances where some substances or articles could meet the definition of Class 1 but have been deemed not appropriate for Class 1, but for another class, for reasons such as net explosive quantity and societal benefit. All competent authorities recognized the importance of regulating intentional explosives by definition.

2025/26 (COSTHA) Proposed definition for life-saving appliances –

  • Conclusion: The EWG recognized the value of a glossary term for “life-saving appliances” but suggested that the author focus the definition on protecting people and consider limits for its application.

2025/27 (COSTHA) Clarification for the application of protective features –

  • Conclusion: After a robust discussion, the views of the competent authorities differed as to whether the mitigating feature should be removed for exclusion testing. Although it was recognized that the UNMR applies to transport, some countries also utilize it for purposes beyond transport, such as security and safe storage of explosives. The EWG agreed that it would be valuable to list mitigating features as one of the elements for the approval document in 2.1.3.7.4. The EWG’s members were invited to submit detailed comments on the questions in 2025/27 to COSTHA, to refine a future proposal for harmonization across the approaches taken by different competent authorities.

2025/28 (SAAMI) Complex articles containing Class 1 and other classes –

  • Conclusion: There was recognition that the constraints of the current system of precedents of hazards might not fully reflect that the predominant hazard for a complex article may be coming from a class other than explosives. Without a recognized entry, regulators are working from first principles which could be seen as resulting in inconsistent determinations. There was recognition in the room that the rapidly developing state of the art will require addressing if a harmonized approach to the classification of complex articles is to be taken. However, many competent authorities were comfortable with the existing framework. Several competent authorities identified that real-life examples of complex articles would need to be provided if a comprehensive analysis of potential approaches is to take place. Pending that analysis individual competent authorities will continue to use local approaches to come to an appropriate determination. SAAMI was invited to reintroduce this topic to the group once they have been able to identify a set of representative examples of complex articles for consideration.

2025/35 (Austria) + INF.15 (Austria) Classification criteria for jet perforating guns –

  • Conclusion: Many of the competent authorities would expect the classification of JPGs as 1.4D to be undertaken by following the current test based approach and therefore did not support Austria’s proposals. There was, however, recognition that local approaches could be appropriate where additional risk mitigation or reduction measures have been put into place. There was also recognition in the group that the state of the art is changing, and that these changes in art are likely to introduce a wider range of products that can be classified as 1.4D by test. IME, United States of America and other delegates agreed to continue discussions intersessionally to explore updates to US1 given the evolution of JPG technology.

INF.34 (Cefic) Revisiting the 1 (a) test criterion of Special Provision 237 when classifying nitrocellulose membrane filters under UN 3270 –

  • Conclusion: The EWG supports the proposal and requests the authors return with a formal proposal that takes into account the feedback received during the meeting. The EWG agreed that any exclusion of nitrocellulose membrane filter products from Class 1, and its inclusion in UN 3270 shall be determined by a decision of a competent authority.

INF.43 (SAAMI) Classification of thermite substances and articles + INF.44 (United Kingdom) Status report for the Transport of Dangerous Goods informal working group on the classification of thermites and thermite containing articles –

  • Conclusion: The EWG supported the United Kingdom and SAAMI working together on this effort. There was general recognition in line with the survey conducted by the United Kingdom that traditional railway type thermites and other similar industrial products would generally be better regulated either in a class other than Class 1 or where their properties were appropriate as deregulated goods. A number of regulators supported a hybrid approach to determining an appropriate classification for thermites e.g. by using a combination of definitions, intended use, experience, and tested properties to identify risk, hazards, and proportionate controls. The IWG was encouraged to begin working on potential options that could deliver this hybrid approach. Further, the EWG requests direction from the TDG Subcommittee regarding medium and low hazard demining devices containing thermites and other similarly insensitive pyrotechnic compositions. The EWG asks if in the opinion of the TDG Subcommittee such articles should potentially be given special consideration for classification outside Class 1 given their humanitarian application and societal benefits.

INF.54 (China) Packing group assignment/ categorization of flammable solids other than metal powders –

  • Conclusion: The EWG recognized the problem that China has brought forward and supports its work to develop a solution. EWG participants were invited to collaborate with China on this work.

INF.7 (China) Classification of substances evolving flammable vapour which can also meet the criteria for flammable solids of Division 4.1 –

  • Conclusion: The EWG agreed to the premise of the paper and made general comments for its improvement. The authors were encouraged to take the feedback and return with a formal proposal.

INF.26 (Cefic on behalf of the IWG) Informal working group on polymerizing substances and self-accelerating polymerization temperature (SAPT) –

  • Conclusion: After a positive discussion where competent authorities voiced their support, the EWG agreed that the direction the working group was heading is appropriate. EWG participants were invited to provide any specific feedback to the working group.  

INF.35 (France, Germany) Round Robin testing program – Tests UN0.1 and Uno.3 final results and preliminary consequential amendments –

  • Conclusion: The EWG’s members were supportive of the approach taken and the direction of the proposals. EWG members were invited to provide detailed comments on the proposals to France. The EWG recognized the value of this work and supported its approach of improving the consistency in the application of testing methodologies by undertaking round-robin testing.

INF.18 + INF.19 + INF.39 (Germany on behalf of the IWG) Status report for the Globally Harmonized System informal working group on combinations of physical hazards –

  • Conclusion: The EWG thanked Germany for the update on the IWG’s efforts and agreed with its direction. EWG participants were encouraged to submit detailed comments to the German expert for the IWG to consider.

2025/6 (SAAMI) + INF.4 (SAAMI) Manual of Tests and Criteria – Part 1 Explosives testing related to chapter 2.17 of the Globally Harmonized System –

  • Conclusion: The EWG concluded that SAAMI is correct in its first question in 2025/6, however the EWG also identified that conditions for the classification for transport of desensitized explosives, as detailed in Sections 2.4.2.4.2 and 2.3.1.4 of the UNMR, can also be found in packing instructions and special packing provisions. Following initial discussions, SAAMI chose to withdraw its proposal para 16(c) of its paper and invited members of the EWG to work with it intersessionally to refine the scope of any future proposal.

This concludes the summary of discussions of the formal and informal papers discussed at the 66th Session of the UN Subcommittee of Experts on the Transport of Dangerous Goods.

End of Day 5 and the 66th Session. [COSTHA]