The UN published the 7th biannual revision of the Globally Harmonized System of Classification and Labeling (GHS) in July2017. The amendments are given in a 24-page document, ST/SG/AC.10/46/Add.3, and are summarized here.

The amendments to GHS primarily address addition of the GHS Rev. 6 defined relevance limit for aspiration hazard at >=1% to Table 1.5.1; revised criteria for categorization of flammable gases; miscellaneous clarifications in the definitions of some health hazard classes; changes to Section 14.7 subheader and guidance on bulk cargo; further revision and rationalization of precautionary statements; and a new example addressing labelling of small packagings with fold-out labels..

Changes are discussed here in accordance with where each change is found in the GHS book, starting with the introduction section.

Introduction
The definitions for “skin corrosion”, “skin irritation”, “serious eye damage”, “eye irritation”, “dermal corrosion”, and “dermal irritation” are deleted from chapter 1.2, presumably to avoid conflicts with the definitions in the chapter 3 on health hazards.

The definitions of “respiratory sensitizer” and “skin sensitizer” are amended from “substance” to “substance or mixture” and the language in “respiratory sensitizer” is clarified as hypersensitivity “occurring after inhalation” instead of “following inhalation.”

The cut-off value/concentration limit for which an SDS should be provided (‘relevance limit’) in Table 1.5.1 is set to >=1% for aspiration hazards category 1 and 2. This updates the table to be consistent with the text of 3.10.3.3.1, into which the following text was inserted in the 6th revision of GHS: "The 'relevant ingredients' of a mixture are those which are present in concentrations >= 1%."

Paragraph 1.5.3.3.3 detailing the legacy standards taken into account in setting guidance on preparation of an SDS is deleted and the reference to Annex 4 is moved to the end of 1.5.3.3.1. Paragraphs are renumbered accordingly.

The reference to liquids is removed in the applicability for cargoes transported in bulk according to IMO in both the descriptive text (new 1.5.3.3.3, formerly 1.5.3.3.4) and in Table 1.5.2, Minimum information for an SDS, item 14(f).

Physical hazard classifications
No new physical hazards are added to GHS. Significant changes to the classification methods arise only in the flammable gases class.

Flammable gases:

• The classification criteria extend flammable gas category 1 to include 1A and 1B, and now prescribe that flammable gases that are pyrophoric and/or chemically unstable are always classified in flammable gas category 1A.
• Note that in the absence of data allowing assignment to flammable gas category 1B, the category 1A must be assigned.
• Table 2.2.1 is redesigned accordingly, as shown here. Three notes are added and the two notes already referencing pyrophoric gases are moved to the combined table 2.2.1. Separate tables 2.2.2 and 2.2.3 are deleted as the information is all combined to table 2.2.1.

• The table on label elements (now Table 2.2.2) clarifies the applicable elements by including all relevant elements for each classification case instead of treating the “additional sub-categories categories” as additive to the flammable gas elements. (Note that new category 1B of flammable gas takes the H-statement formerly associated with category 2, but retains the pictogram and signal word related to category 1.)

• The decision logic, guidance, and example calculation are significantly changed and should be reviewed in detail by anyone making classifications in this hazard class.

Other minor changes in chapter 2:

• Clarify “practical explosive or pyrotechnic effect” by removing the comma typo after practical at 2.1.1.2(c);
• Remove criteria at 2.6.4.2.2, to avoid conflict with classification criteria elsewhere;
• Clarify the sample is 100mm length in 2.7.2.2;
• Clarifications in 2.17 that conditions excluding classification as desensitized explosives apply to products in the desensitized state and clarifying prhases or correcting typos with no significant effect on the classification method.

Health hazard classifications
No new health hazards are added to GHS. No change to GHS mixture classification logic is required.

Chapter 3 amendments:

•  Clarify language embracing newer test methods for assigning acute toxicity based on sub-lethal effects and reinforcing the use of data from human experience;
• Clarify the acute toxicity estimate values and criteria, without significantly changing the method so long as the limits have been understood as inclusive (<=) limits; 
• Clarify the definitions of “skin corrosion” and “skin irritation”, to avoid conflict with classification criteria elsewhere and deletion of footnote referencing “working definition”; 
• Clarify the definitions of “serious eye damage” and “eye irritation”, to avoid conflict with classification criteria elsewhere and deletion of footnote referencing “working definition”; 
• Clarify the definitions of “respiratory sensitization” and “skin sensitization”, consistent with the changed definitions in chapter 1 and deletion of footnote referencing “working definition”; 
• Add a definition of “germ cell mutagenicity” as item 3.5.1.1 and renumbering of subsequent paragraphs of 3.5.1 accordingly; 
• Clarify the definition of “reproductive toxicity”; 
• Add a definition of “specific target organ toxicity” as items 3.8.1.1 and 3.9.1.1, for single exposure and repeated exposure respectively, and renumbering of subsequent paragraphs of 3.8.1 and 3.9.1 accordingly; 
• Clarify the definitions and guidance text 3.10.1 and its subparagraphs for aspiration hazard.

Environmental hazard classifications
No new environmental hazards are added to GHS. No amendments to chapter 4 are made.

Annex I
Annex I is updated with the insertion of an amended table A1.2 for flammable gases, following the new structure of categories set out in chapter 2.2.

Annex III
Annex III Table A3.1.1 references for flammable gases are updated, following the new structure of categories set out in chapter 2.2. Note the significant change in the use of H221, Flammable gas, for the new category 1B of flammable gas. H220, Extremely flammable gas, remains in use for the category 1A. Note that the hazard category for chemically unstable gases is described here as “1A, chemically unstable gas A” or “1A, chemically unstable gas B” suggesting how these categories should be communicated.

Paragraph A3.2.3.3 is also updated to reflect the new P280 statement.

New or Revised P-statements
Some P-statements have been revised for ease of comprehension or more efficient application. The table below shows the Rev. 6 phrase and Rev. 7 phrase side-by-side for ease of comparison:

Due to the new provisions in Annex III on P-statement flexibility, it is anticipated that many self-created combination statements may be needed, modeled on existing combination statements.

New or Revised Conditions of Use
The conditions for use for some P-statements have been revised for ease of comprehension or more efficient application. The table below shows the conditions of use for Rev. 6 phrase and Rev. 7 phrase side-by-side for ease of comparison:

Changes in Section 3 on the use of precautionary statements
The guidance in 3.3.2 on the allocation of P-statements has been significantly updated, and changed to “Flexibility in the use of precautionary statements”. This potentially empowers chemical suppliers in some very important ways:

• Those responsible for labelling may omit statements that are not appropriate or redundant (subject to any requirements of the competent authorities)
• Further combinations of P-statements may be designed by the users, based on the “examples” of combined P-statements already existing
• Variations in text not affecting the safety message are permitted, which may be a major help with translation divergence (also subject to any requirements of the competent authorities)
• Rules for prioritizing statements concerning medical response are elucidated. It is required to use a route (IF statements P301 through P309) with all medical response statements except P314 - Get medical advice/attention if you feel unwell, and P315 - Get immediate medical advice/attention. When a medical response statement applies to two routes, a combined IF should be created. When three or more, P308 - IF exposed or concerned: may be used instead of a combined routes statement. IF statements with symptoms (P332, P333, P337, P342) must always be used, and may also be combined with other routes or with P308, per the aforementioned rules of 3 or more routes

The target audience for general precautionary measures is redefined as “consumers and employers/workers” instead of “general public, the commercial user and the industrial worker.”

Some tables with the array of elements applicable by hazard class and category has been amended. These tables are reorganized with the symbol name, signal word, and hazard statements specified for each hazard category, and some categories that were differentiated only by symbol, signal word and/or hazard statement are merged into tables that better show where P-statements are shared.

The table below shows the effect of this reorganization and on application of P-statements in Rev. 6 and Rev. 7 side-by-side for ease of comparison; only P-statements that have changed are shown (all others from Rev. 3 still apply):

Section 5 examples of pictograms
The South African square pictograms are deleted. Only EU blue circles remain as examples.

Annex IV
The fundamental burning velocity, which is a required element of data necessary to classify a flammable gas substance or mixture as category 1B is add to the table A4.3.9.2 on supplemental data for section 9 of the SDS.

The language on transport in bulk according to IMO instruments is amended to extend the coverage of section 14 of the Safety Data Sheets to all bulk cargoes, regardless of their physical state. This allows the use of the SDS to comply with documentation provisions of the IMO instruments: IMO instruments: e.g., chapter VI or VII of SOLAS, Annex II or Annex V of MARPOL, the IBC Code, the IMSBC Code and the IGC Code (or earlier versions eGC Code or GC Code). This results in a change to the subheader 14.7 of the SDS: “14.7 Transport in bulk according to IMO instruments”

Annex VII

A new example of labelling using fold-out labels is given. The example addresses tiny ampoules supplied with reduced label elements on the plastic sleeve around each individual ampoule and full labelling on the outer package.