Making progress on the Orange Book

QUESTIONS, QUESTIONS

MULTIMODAL • THE UN EXPERTS REMAIN CONSTRAINED PHYSICALLY BY THE PANDEMIC RESPONSE BUT HAVE MANAGED TO MAKE HEADWAY ON THE UN MODEL REGULATIONS

THE UN SUB-COMMITTEE of Experts on the Transport of Dangerous Goods (TDG) held its 59th session this past 29 November to 8 December 2021, with Duane Pfund (US) in the chair and Claude Pfauvadel (France) as vice-chair. It was attended, either in person or online, by representatives of 23 countries, the EU, the Intergovernmental Organisation for International Carriage by Rail (OTIF), the UN Food and Agriculture Organisation (FAO), the International Civil Aviation Organisation (ICAO), the International Maritime Organisation (IMO), the World Health Organisation (WHO) and 25 non-governmental organisations. In addition, observers from Latvia, Luxembourg and Turkey also took part.

This second meeting of the Sub-committee for the current biennium would in more normal times be the busiest of the four sessions; however, ongoing Covid-19 response measures, financial constraints triggered by the UN liquidity crisis, renovation work at the Palais des Nations that limited the number of meeting rooms available for hybrid meetings and the allocation of interpretation services all meant that the volume of work was less than might have been hoped.

Nevertheless, the Experts did manage to cover a lot of ground, including some new items, and made progress towards the adoption of the text that will form the 23rd revised edition of the UN Model Regulations, due to be agreed by the parent Committee of Experts at its meeting this coming December.

START WITH A BANG As usual, the agenda began with matters relating to explosives, although there was a noticeable reduction in the number of papers to be considered. The chair of the Working Group on Explosives noted that, during work to revise Test Series H in the Manual of Tests and Criteria (MTC), it emerged that the density of silicone oil in 28.3.6 and 28.4.2.3.1(a) was given without units. It was recommended that the unit g/cm2 was used, which was agreed and adopted as a correction to the seventh revised edition of MTC.

The Working Group had also spotted some errors in two equations in A10.2.3.8; again, these were corrected.

The chair of the Working Group on Explosives also reported that two different units for density – kg/cm2 and g/cm2 – are used throughout MTC (and A3.3 has no units at all) and recommended that these should be brought into line. A formal proposal on this topic will be presented at a subsequent meeting.

The European Chemical Industry Council (Cefic) appealed for a new entry for 5-Trifluoromethyltetrazole, sodium salt (TFMT-Na), a recently developed insecticide precursor. In its dry form it is explosive and so is only handled and transported as a homogeneous solution in acetone. The competent authorities in Germany, on the request of industry, have issued a temporary approval for its transport as UN 3379 Desensitised explosive, liquid, nos. However, Cefic felt that, in light of the anticipated increase in the volume of the substance that will be shipped internationally, a separate entry would be valuable.

Those experts who spoke were generally supportive of the proposal but, as toxicity tests have not yet been completed, they felt it premature to make a decision at this point. It was also queried why the proposal included the use of special packing provision PP26, which requires lead-free packagings; Cefic said this is needed to prevent the formation of hazardous solid salts. Cefic invited delegates to send their comments in writing and volunteered to prepare an updated document for consideration at the next session.

The chair of the Working Group on Explosives brought the Experts up to date with inter-sessional discussions on classification issues related to fire extinguishing devices, which had identified a possible way forward. This would involve only those devices with a 1.4S classification, independent of the packaging used (if any). It may be useful to adopt a test similar to that in 2.1.3.6.4 of the Model Regulations to help define those devices that could be excluded from the scope of the Regulations. The Sub-committee welcomed the progress made and invited further discussion at the next session.

LISTING, PACKAGING AND CLASSIFICATION Cefic brought its usual proposal for the listing of new organic peroxides. The Sub-committee accepted the suggestions, making one change and adding three more substances to the table in 2.5.3.2.4 and making one revision to packing instruction IBC520 in 4.1.4.2.

The Council on Safe Transportation of Hazardous Articles (COSTHA) proposed a new Division 4.1 entry for quinone dioxime (QDO), which is widely used as a rubber vulcanisation curative in the manufacture of tyres and has been manufactured and transported without any known incident for more than sixty years. QDO is shipped in significant volumes internationally, either unregulated or as Division 4.1, PG II or PG III, according to classification data from the European Chemicals Agency (ECHA). However, recent registrations under REACH in the EU have indicated that the material can meet the criteria in Test Series 6(c), which would call for a classification under Class 1. COSTHA’s proposal sought to remove this uncertainty and to pin down a Division 4.1 entry for the material.

In particular, COSTHA pointed to 2.1.1.1(a) and 2.1.1.3(a) in the Model Regulations, which in its view indicate that at Class 1 designation is inappropriate for material that is not intended to function as an explosive and is already assigned to another Class or Division. Similar provisions can be found in ADR, the US Hazardous Materials Regulations (HMR) and Canada’s Transportation of Dangerous Goods (TDG) Regulations.

The Sub-committee was not won over by COSTHA’s argument; on the contrary, most of those who spoke preferred to consider a Class 1 entry and it was decided to refer the matter to the Working Group on Explosives.

China returned to an issue it had raised at the previous session, namely the possibility of exempting manufactured articles containing small amounts of gallium from the regulations by an extension of the scope of special provision 366. There had been no opposition to the proposal but disagreement on how best to achieve its aims. China now returned with two options: either a new entry for gallium contained in manufactured articles, with amendments to special packing provision PP90 and special provisions 365 and 366; or a new special provision to apply to the existing entry UN 2803 Gallium.

Again, there was little opposition to the concept, but no agreement on the best way forward. China will consider the comments made and return with a revised proposal.

Spain noted that, in 2012, the Subcommittee had removed the packing groups assigned to all articles in the Dangerous Goods List, and additionally introduced text into 2.0.1.3 and the Guiding Principles expressing this rule. However, packing groups are still assigned to two entries for articles: UN 2870 Aluminium borohydride in devices and UN 3165 Aircraft hydraulic power unit fuel tank, thus contradicting 2.0.1.3.

The Sub-committee acknowledged the problem and expressed a preference to delete the packing group assignments for these two entries, with the addition of a general packaging performance requirement in packing instruction P301. Despite opposition from the US, they also agreed that a slight rewording of the explanation in the Guiding Principles was of value. Spain will work those comments into an official proposal for the next session.

ISSUES SURROUNDING FIRE EXTINGUISHING SYSTEMS

AND CYLINDERS, AND THEIR INITIATION, CONTINUE TO

Tetramethylammonium hydroxide (TMAH) is classified as corrosive, both in solid (UN 3423) and liquid (UN 1835) form. However, the Netherlands reported that several fatalities have occurred after spills of TMAH solution and argued that a toxic hazard should be recognised in the classification. Human experience and animal testing support both corrosive and toxic hazards but do not make clear what packing group would be appropriate and, in an informal document, the Netherlands sought input from the Experts.

There was a general agreement that the classification of TMAH should be revised, preferably based on existing human data, if available, otherwise on animal data. The Netherlands invited all experts to send written comments and offered to prepare an official document for consideration at the next session.

China returned to a topic it had raised during the previous biennium, namely the use of batteries (wet, non-spillable) installed in cargo transport units (CTUs) and used as portable energy storage devices, particularly

QDO, USED AS A VULCANISING AGENT IN THE RUBBER

SECTOR, MAY HAVE TO BE RECLASSIFIED AS AN

EXPLOSIVE, BASED ON REACH REGISTRATIONS to power fixed fire extinguishing systems. China proposed a new entry, analogous to UN 3536 Lithium batteries installed in cargo transport unit.

There was some support for China’s proposal but most of the Experts who spoke felt that it needed further work. Spain was of the opinion that the definition of CTU in UN 3536 needed to be finalised before going any further. Experts were invited to send written comments to China so that an official proposal can be made at the next session.

During its work to harmonise the names of UN numbers in the Spanish language version of the regulations, Spain had noted some inconsistencies between the UN Model Regulations and RID/ADR. In particular, Spain mentioned UN 2426 Ammonium nitrate (hot concentrated solution). At its March 2021 session, the RID/ADR/ADN Joint Meeting had agreed to harmonise with the UN Model Regulations but invited Spain to bring the matter to the attention of the UN Subcommittee to determine if other measures were needed.

Having compared the UN Model Regulations with RID/ADR and the International Maritime Dangerous Goods (IMDG) Code, Spain now suggested some textual amendments to special provision 252. There was broad support for the proposal but not for Spain’s solution. Instead, after discussion, it was decided to re-write SP 252 completely. Two figures have been left in square brackets pending confirmation. 252 (1) Ammonium nitrate hot concentrated solutions can be transported under this entry provided: (a) The solution contains not more than 93 % ammonium nitrate; (b) The solution contains at least 7 % water; (c) The solution contains not more than 0.2 % combustible material; (d) The solution contains no chlorine compounds in quantities such that the chloride ion level exceeds [0.02] %; (e) The pH of an aqueous solution of 10 % of the substance is between [5 and 7], measured at 25 ºC; and (f) The maximum allowable transport temperature of the solution is 140 ºC. (2) Additionally, ammonium nitrate hot concentrate solutions are not subject to these Regulations provided: (a) The solution contains not more than 80 % ammonium nitrate; (b) The solution contains not more than 0.2 % combustible material; (c) The ammonium nitrate remains in solution under all conditions of transport; and (d) The solution does not meet the criteria of any other class or division.

China urged that the provisions in 6.1.3.1 for the UN specification marking of packagings be made more rigorous. In particular, the requirement for the markings to appear “on the top or on a side” of packagings raises a safety issue with removable head packagings, as the head may be lost or replaced during use. The Sub-committee expressed its general support for the proposal but some Experts felt more work was needed on the proposed wording of the amendment to 6.1.3.1 and the accompanying transitional provision. China plans to return at the next session with a revised proposal. The second part of this two-part report on the UN TDG Sub-committee’s session in November and December 2021 in next month’s HCB will cover discussion of energy storage systems, the transport of gases and miscellaneous proposals for amendment.