GHS Revision 10

Last reviewed 18 October 2023

The UN GHS Purple Book is updated every two years and the tenth revised edition of GHS (GHS Rev 10) was published in July 2023. Caroline Raine discusses the changes in this feature article.

Introduction

Globally Harmonised System of Classification and Labelling of Chemicals (GHS) revision 10 has been published and is available online in English and French. The English version can be accessed via the UNECE website.

The amendments to the ninth revised edition of the GHS include:

  • the classification procedure for desensitised explosives (chapter 2.17)

  • the use of non-animal testing methods for classification of health hazards, in particular: skin corrosion/irritation (chapter 3.2), serious eye damage/irritation (chapter 3.3) and respiratory or skin sensitization (chapter 3.4)

  • further rationalization of precautionary statements to improve users’ comprehensibility while taking into account usability for labelling practitioners

  • the review of annexes 9 and 10 to ensure alignment of the classification strategy, guidance and tools on metals and metal compounds with the provisions for long-term aquatic classification toxicity in chapter 4.1.

Classification of Desensitised Explosives (Chapter 2.17)

The classification for desensitised explosives has been redefined aligning it with the latest advancements in explosive hazard assessment. The classification criteria has been amended to include;

A phlegmatized explosive should be considered for inclusion in this class if, in that state, the exothermic decomposition energy is ≥ 300J/g.

NOTE 1: The exothermic decomposition energy may be estimated using a suitable calorimetric technique (see s.20, subsection 20.3.3.3 in Part II of the Manual of Tests and Criteria).

NOTE 2: Substances and mixtures with an exothermic decomposition energy < 300J/g should be considered for inclusion in other physical hazard classes (eg as flammable liquids or flammable solids).

A phlegmatized explosive should be considered for inclusion in this class if, in that state, it meets the following criteria.

  1. It is not intended to produce a practical explosive or pyrotechnic effect.

  2. It is phlegmatized to an extent that:

    1. it has no mass explosion hazard in accordance with test 6 (a) or 6 (b) of the Manual of Tests and Criteria

    2. it is not too sensitive or thermally unstable in accordance with test series 3 of the Manual of Tests and Criteria

    3. it is too insensitive for inclusion into in the class of explosives in accordance with test series 2 of the Manual of Tests and Criteria

  3. It presents no mass explosion hazard and has a corrected burning rate ≤ 1200 kg/min in accordance with the burning rate test of subsection 51.4 of the Manual of Tests and Criteria.

Note:

Phlegmatized explosives which do not meet the criteria of 2.17.2.2 should be classified as explosives (see chapter 2.1).

Decision logic

To classify desensitized explosives, data for the sensitivity, thermal stability, explosive potential and the corrected burning rate should be determined as described in Part I and Part V of the Manual of Tests and Criteria. Where a mixture contains nitrocellulose, additional data for the stability of the nitrocellulose as described in appendix 10 of the Manual of Tests and Criteria are needed in order to be used in nitrocellulose mixtures considered for this class. Classification is according to decision logic 2.17.1.”