Last reviewed 17 December 2021

In this feature article, Caroline Raine discusses the changes being brought into the Globally Harmonised System of Classification and Labelling of Chemicals (GHS) Revision 9. The UN GHS Purple Book is updated every two years and the nineth revised edition of GHS (GHS Rev. 9) was published earlier in 2021.

Introduction

Globally Harmonised System (GHS) Revision 9 has been published and is available online in both English and French.

The amendments to the eighth revised edition of the GHS include the revision of:

  • chapter 2.1 (explosives) to better address their explosion hazard when they are not in their transport configuration

  • decision logics

  • classification and labelling summary tables in Annex 1

  • precautionary statements.

References to OECD test guidelines for the testing of chemicals in annexes 9 and 10 have also been updated.

The English version can be accessed via the UNECE website.

Revision of Chapter 2.1

Previous GHS classification systems for explosives were very closely based on the UN Model Regulations (ie the transport regulations). The challenge here was that it relies on there being a transport configuration (packaging) so a model division can be assigned. And that is problematic as GHS applies to sectors where transport is not necessarily valid, for example during manufacture or use.

Chapter 2.1 was revised because of:

  • substances, mixtures and articles that have explosive properties, escape classification as explosives due to their transport packaging

  • substances, mixtures and articles where the GHS classification is different when the explosive is removed from the transport packaging

  • substances, mixtures and articles may not be packaged for transport.

Revision 9 of GHS now requires that all explosives are classified regardless of the sector.

Table 2.1.1: Criteria for explosives

Chapter 2.1.2.1 of GHS shows that explosive substances, mixtures and articles of this class are classified into one of two categories, and for Category 2 into one of three sub-categories according to the following table.

Category

Sub-category

Criteria

1

Explosive substances, mixtures and articles which:

  1. have not been assigned a division and which:

    1. are manufactured with the view of producing an explosive or pyrotechnic effect; or

    2. are substances or mixtures which show positive results when tested in test series 2 of the Manual of Tests and Criteria

    or

  2. are out of the primary packaging of the configuration to which a division was assigneda, unless they are explosive articles assigned a division:

    1. without a primary packaging; or

    2. in a primary packaging that does not attenuate the explosive effect, taking into account also intervening packaging material, spacing or critical orientation.

2

2A

Explosive substances, mixtures and articles which have been assigned:

  1. Division 1.1, 1.2, 1.3, 1.5 or 1.6; or

  2. Division 1.4 and are not meeting the criteria for sub-category 2B or 2C.b

2B

Explosive substances, mixtures and articles which have been assigned Division 1.4 and a compatibility group other than S, and which:

  1. do not detonate and disintegrate when functioned as intended; and

  2. exhibit no high hazard eventc in test 6 (a) or 6 (b) of the Manual of Tests and Criteria; and

  3. do not require attenuating features, other than that which may be provided by a primary packaging, to mitigate a high hazard eventc.

2C

Explosive substances, mixtures and articles which have been assigned Division 1.4 compatibility group S, and which:

  1. do not detonate and disintegrate when functioned as intended; and

  2. exhibit no high hazard eventc in test 6(a) or 6(b), or in the absence of these test results, similar results in test 6(d) of the Manual of Tests and Criteria; and

  3. do not require attenuating features, other than that which may be provided by a primary packaging, to mitigate a high hazard eventc.

a Explosives in Category 2 that are removed from their primary packaging for use remain classified in Category 2, see 2.1.1.3.4.

b The manufacturer, supplier or competent authority may classify an explosive of Division 1.4 as sub-category 2A on basis of data or other considerations even if it meets the technical criteria for sub-category 2B or 2C.

c A high hazard event is exhibited when performing test 6 (a) or 6 (b), according to the Manual of Tests and Criteria, by:

  1. a significant change in the witness plate shape, such as perforation, gouge, substantial dent or bowing; or

  2. instantaneous scattering of most of the confining material.

Category

1

2

Sub-category

Not applicable

2A

2B

2C

Symbola

Exploding bomb

Exploding bomb

Exploding bomb

Exclamation

mark

Signal word

Danger

Danger

Warning

Warning

Hazard statement

Explosive

Explosive

Fire or projection hazard

Fire or projection hazard

Additional hazard statement

Very sensitiveb

or

May be sensitivec

Not applicable

Not applicable

Not applicable

a For divisions 1.4, 1.5 and 1.6 no symbol appears on the label for transport, according to the UN Model Regulations.

b To be assigned additionally to explosives that are sensitive to initiation as determined by test series 3 or 4 of the Manual of Tests and Criteria. May also be applied to explosives sensitive to other stimuli, eg electrostatic discharge.

c To be assigned additionally to explosives for which sufficient information on their sensitivity to initiation is not available.

Note:

Substances and mixtures excluded by 2.1.1.2.2 (c) (v) still have explosive properties. The user should be informed of these intrinsic explosive properties because they have to be considered for handling — especially if the substance or mixture is removed from its packaging or is repackaged — and for storage. For this reason, the explosive properties of the substance or mixture should be communicated in sub-section 2.3 (Other hazards which do not result in classification) and Section 9 (Physical and chemical properties) or 10 (Stability and reactivity) of the Safety Data Sheet in accordance with Table 1.5.2, and other sections of the Safety Data Sheet, as appropriate.

In addition, there are three new hazard statements for explosives.

H209

Explosive

Explosives (chapter 2.1)

1, 2A

H210

Very sensitive

Explosives (chapter 2.1)

1

H211

May be sensitive

Explosives (chapter 2.1)

1

Decision logics

All decision logics have been reviewed and updated.

Annex 1 updates

The classification and labelling summary tables in Annex 1 have been revised.

A1.1 Explosives (see Chapter 2.1 for classification criteria)

a Under the UN Model Regulations, (*) indicates the place for compatibility group and (**) indicates the place for division - to be left blank if explosive is the subsidiary hazard.

b Additional hazard statements for explosives that are sensitive to initiation or for which sufficient information on their sensitivity is not available (see section 2.1.3 of Chapter 2.1).

Revision and further rationalization of precautionary statements

The following changes to precautionary statements have occurred.

  • P203 has been updated, adding 1A.

    1A

    Chemically unstable gas A

    Chemically unstable gas B

  • P210 has been updated to:

    1A

    Flammable gas

    Pyrophoric gas

    Chemically unstable gas A

    Chemically unstable gas B

    1B, 2

  • P222, has 1A added before Pyrophoric gas.

  • P230 “Keep wetted with…”becomes “Keep diluted with…:” and the conditions for use will now read as:

    “- for explosive substances and mixtures that are diluted with solids or liquids, or wetted with, dissolved or suspended in water or other liquids to reduce their explosive properties.…Manufacturer/supplier or competent authority to specify appropriate material”.

  • P236 is a new precautionary statement:

    (1)

    (2)

    (3)

    (4)

    (5)

    P236

    Keep only in original packaging; Division … in the transport configuration.

    Explosives

    (chapter 2.1)

    2A, 2B, 2C

    • To be applied for explosives assigned a division within Class 1 for transport.

    • May be omitted for single packaging where the transport pictogram displaying the division (within Class 1) appears.

    • May be omitted where the use of different outer packaging results in different divisions for transport.

    …Manufacturer/supplier or competent authority to specify the division for transport.

  • P264 has been updated to read: “Wash hands [and…] thoroughly after handling.” “Serious eye damage (chapter 3.3)”.

    “… Manufacturer/supplier or the competent authority to specify parts of the body to be washed after handling.” with “- text in square brackets to be used when the manufacturer/supplier or the competent authority specify other parts of the body to be washed after handling.”.

  • P265 is a new precautionary statement P265:

    (1)

    (2)

    (3)

    (4)

    (5)

    P265

    Do not touch eyes.

    Serious eye damage (chapter 3.3)

    1

    Eye irritation (chapter 3.3)

    2/2A, 2B

  • P264+P265 are also new.

    (1)

    (2)

    (3)

    (4)

    (5)

    P264+P265

    Wash hands [and…] thoroughly after handling. Do not touch eyes.

    Serious eye damage (chapter 3.3)

    1

    • text in square brackets to be used when the manufacturer/supplier or the competent authority specify other parts of the body to be washed after handling.

    Eye irritation (chapter 3.3)

    2/2A, 2B

Annexes 9 and 10

A new explanatory note has been added to the start of Annex 9.

NOTE: The text of Annex 9 is largely based on the “Guidance document on the use of the harmonised system for the classification of chemicals which are hazardous for the aquatic environment” published by OECD in 2001, as Series on Testing and Assessment No.27 (ENV/JM/MONO(2001)8). The Guidance document has remained unchanged since its publication in 2001, but since then, new OECD Test Guidelines or Guidance Documents have been adopted which are an additional source of information. For a list of updated references, refer to appendices V and VI to Annex 9.”

Finally, both Annexes 9 and 10 have had the references to OECD test guidelines for the testing of chemicals updated.

Conclusions

  • Revision 9 of GHS has been published but has not yet been adopted in many countries.

  • Keep up to date with local regions to establish how the changes are implemented. Within the EU this will be through European Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures (CLP) and in the England, Scotland and Wales through GB CLP.

  • There will inevitably be different deadlines imposed.