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Definition

The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) is continuously evolving international consensus system developed by the United Nations for classifying and labeling hazardous chemicals. The GHS is designed to streamline the hazard assessment, labeling, and hazard communication requirements within and between the countries that adopt it by promoting common, consistent criteria for classifying chemicals according to their health, physical and environmental hazards, and to develop compatible labeling, safety data sheets (SDS's; formerly known as MSDS's) and other information based on those classifications.

GHS resolves many, but not all, differences between SDS's and labels between, for example, the US, Canada, and the European Union.

OSHA adopted many (but not all) GHS Revision 7 principles in its 2024 update to 29 CFR 1910.1200, the OSHA Hazard Communication Standard (HCS), which is being phased in through May 19, 2028. The prior version, HCS 2012 took full effect in 2016 and replaced the prior version, HCS 1994, which is no longer in force.

Additional Info

As discussed in the brief history of the GHS at the UNECE, the first edition of the GHS was adopted in December 2002 and published in 2003. Since then, the GHS has been updated, revised and improved every two years as needs arise and experience is gained in its implementation. The eleventh revised edition of the GHS (GHS Rev 11) was published in 2025.

GHS is a model standard and implementation from country to country will vary. For example, OSHA's HCS currently covers acute toxicity with respect to SDSs. The GHS's coverage of acute toxicity is quite broad, covering consumer protection in addition to occupational concerns. As OSHA has no regulatory authority for consumer issues/products, the HCS will never be able to incorporate all the changes to acute toxicity that the GHS suggests. This does not stop other Federal agencies such as the Consumer Product Safety Commission from enacting such legislation under their own purview, however.

Other US agencies affected by the GHS include:

• The US Department of Transportation's Pipeline and Hazardous Materials Safety Administration has an article on Global Harmonization of Hazard Classification and Labeling Systems.
• The US Environmental Protection Agency has a web site on Pesticide Labels and GHS: Comparison and Samples.

In the European Union (EU), Safety Data Sheets (SDS) and labels issued prior to June 1, 2015 were required to use a uniform coding system of risk phrases and safety phrases to communicate risks and precautions. The phrases were accompanied by numbers so the phrases can be easily translated or understood in multiple languages. The GHS takes a similar approach but risk phrases and safety phrases have been replaced (see Annex 3 Section 1). Risk phrases have become Hazard Statements ("H-statements") and safety phrases are now Precautionary Statements ("P-statements"). The EU transition required modifications and additions to the existing R- and S-phrases and introduced a new numbering system for the P- and H-statements. Note: regardless of system, phrases must always be written out in words; the numbers are provided as a reference only and should never be used as a substitute for the full phrases.

A sampling of GHS resources for other countries includes:

• European Union Classification and Labelling (CLP/GHS) considerations - https://single-market-economy.ec.europa.eu/sectors/chemicals/classification-and-labelling-clpghs_en.
• Canada: WHMIS - https://www.canada.ca/en/health-canada/services/environmental-workplace-health/occupational-health-safety/workplace-hazardous-materials-information-system.html.
• Taiwan: Latest News of GHS in Taiwan - http://ghs.osha.gov.tw/ENG/intro/news.aspx.
• Australia - Adoption of GHS 7 https://www.safeworkaustralia.gov.au/safety-topic/hazards/chemicals/classifying-chemicals/transition-ghs7.

A detailed implementation list for a growing number of countries is available at https://unece.org/ghs-implementation-0.

A 2021 article from ACS Chem Health Saf. titled GHS Implementation to Strengthen Global Chemical Hazard Communication: Will We Ever Get There? discusses the challenges of worldwide implementation of the GHS, including the use of different data sets for hazard classification.

US Rulemaking, HCS 2012

The first regulatory movement to modernize HCS 1994 by incorporating GHS elements into US OSHA regulations began with an Advanced Notice of Proposed Rulemaking (ANPR) on September 12, 2006. A 60 day comment period received over 100 written and electronic comments which generally supported adoption and highlighted the need for harmonization in how chemicals and their hazards are classified in a worldwide marketplace.

On September 30, 2009, OSHA published its proposed rulemaking to incorporate changes per the GHS (US Federal Register 74:50279-50549). You can view this document in HTML on OSHA's web site or download it as PDF file from the US Government Printing Office. The Public Comment period ended December 29, 2009 and gathered several hundred written comments that are available here.

On October 25, 2011, OSHA submitted the final rule to OMB which finished its review on February 21, 2012. On March 20, 2012, OSHA published its Final Rule establishing HCS 2012, which included a phased in series of effective dates from Dec 1, 2013 through June 1, 2016.

The major changes under HCS 2012 versus HCS 1994 were:

• "Hazard determination" was replaced by rigorous hazard classification under which chemical manufacturers and importers are required to determine the hazards of the chemicals they produce or import. Very specific and new criteria were used to address health and physical hazards as well as the classification of chemical mixtures.
• Labels now required a signal word, one or more pictograms, hazard statements, and precautionary statements for each hazard class and category.
• Material Safety Data Sheets (MSDS's) are now referred to more simply as Safety Data Sheets (SDS's). They now have a specific 16 section format that ensures a consistent presentation of important protection information. As you receive new SDS's in your workplace, you simply replace the old MSDS's the way you always have. There is no need to seek out an SDS for a chemical you already have on hand however your workers must be trained on both the older and new labeling and SDS systems, of course.
• Information and training requirements required that all workers be trained in the new label elements and new safety data sheet formats in addition to their regular training requirements of updating hazard communication as new hazards are identified.

A comparison of the 1994 and 2012 HCS is available which strikes out the old language in red, inserts new language in green, and has additional commentary on each section.

US Rulemaking, HCS 2024

HCS 2012 was based on Revision 3 of the GHS. Canada, one of the US's largest trading partners, had a few key differences in their adoption of GHS under WHMIS and, as the GHS continued to evolve, it eventually became necessary for both countries to more closely align their adoption and move to a newer version.

On February 5, 2021, OSHA issued a proposed rule to update the HCS to align with 2017 Revison 7 of the GHS. The public comment period for this proposal ran February 16 through May 19, 2021. The proposed changes were listed under Docket No. OSHA-2019-0001 and include revised criteria for classification of certain health and physical hazards, revised provisions for updating labels, new labeling provisions for small containers, technical amendments related to the contents of Safety Data Sheets, and related revisions to definitions of terms used in the standard. The HCS 2024 Final Rule was published on May 20, 2024, and includes the following effective dates:

The major changes under HCS 2024 versus the HCS 2012 are:

• Maintaining alignment with GHS (primarily Rev 7) and US trading partners such as Canda. Specifically:
  • Update of paragraph (f)(12) for small packages including 3 mL and 100 ml containers.
  • Paragraph (i) – trade secrets was updated with mandatory use of prescribed concentration ranges when exact percentages or percentage ranges of materials are claimed as a trade secret.
  • Appendix A (health hazards) were updated to Rev 7 and incorporated some elements of Rev 8 for non-animal test methods for skin corrosion/irritation to promote the use of alternative methods.
  • Appendix B (physical hazards) were aligned primarily with Rev 7, including tweaks to flammable gases (expanding hazard categories), desensitized explosives, aerosols, and more.
  • Appendix C (label elements) were aligned primarily with Rev 7 and include new or updated hazards, updated guidance, and precautionary statements.
  • Appendix D (Safety Data Sheets) was aligned primarily with Rev 7 and includes revisions to SDS Sections 2, 3, 9, and 11.
• Addressing issues that needed clarification or flexibility:
  • Paragraph (d)(1) - hazard classification. Clarified which hazards must be evaluated and the information required on the label versus the SDS.
  • Paragraph (f)(11) - labels. Added flexibility for label updates on packages that have been released for shipment.
  • Paragraph (f)(12) - labels. Clarified labeling requirements forsmall packages.
• Improved alignment/coordination with other US agencies
  • Paragraph (c) - released for shipment. "Released for shipment" was defined similarly to the EPA's Pesticide Registration and Classification Procedures regulation, 40 CFR 152.3.
  • Paragraph (f)(5) - bulk shipment. Added provisions on label placement and pictograms increased flexibility for shipments that are also regulated by DOT

SDS Relevance

While the original 1984 version of 29 CFR 1910.1200, the OSHA Hazard Communication Standard and its successor, HCS 1994, pre-date the GHS, starting with HCS 2012, GHS became a core element of the Standard. This relationship got even stronger with the release of HCS 2024.

Of the five key areas of the Standard, HCS is a major component of three: 1) hazard classification, 2) labels and other forms of warning, and 3) safety data sheets, and all three underlie a fourth, the written hazard communication program. Only trade secrets are not addressed by GHS.

With respect to SDSs, the GHS and HCS are fully aligned with a standardized 16 part format as codified at Appendix D of HCS 2024. However, remember that the GHS is a model standard. Several key items to keep in mind about the relationship between HCS and GHS are:

1. Appendix D lists only the required minimum content that must be on the sheet. A manufacturer can add additional information to the sheet, if desired.
2. Manufacturers, importers, and distributors are required to survey the available scientific data when authoring the sheet, but they are not required to do any testing. If no data can be found then this must be noted with wording explicitly - spaces cannot be left blank. For example, if the flash point of the substance is not known, the manufacturer must write "flash point: not available" in section 9 of the SDS.
3. OSHA only has jurisdiction over workplaces, not consumer products or environmental protection. Therefore, manufacturers are not required to provide data for sections 12 through 15 of an SDS, however these sections cannot be left blank. Likewise, there are additional elements of GHS that are not implemented by OSHA, such as P100-series precautionary statements.

Further Reading

Your employees can stay informed and comply with OSHA regulations with SDS information stations and compliance products from Safety Emporium.

• OSHA resources:
  • Questions & Answers for OSHA’s 2024 Update to the Hazard Communication Standard (HCS).
  • Small Entity Compliance Guide for Employers That Use Hazardous Chemicals.
  • OSHA Brief: Hazard Communication Standard: Safety Data Sheets
  • OSHA Brief: Hazard Communication Standard: Labels and Pictograms
  • OSHA Fact Sheet: December 1st, 2013 Training Requirements for the Revised Hazard Communication Standard
  • Hazard Communication Quick Cards on SDS, labeling, and pictograms
• UNECE resources:
  • Status of GHS Implementation by country.
  • GHS presentations.
  • Full text of the GHS Revision 9 (2021) including the Annexes which discuss required classification and labeling. Revision 3, the basis of HCS 2012, is also available.
  • GHS guidance provides links to technical resources to assist in classification and understanding of the model standard.
• Globally Harmonized System (GHS) for Classification and Labelling of Chemicals at the US EPA.
• GHS Classification summary at the US NIH.
• Chemical Hazard Classification (GHS) at the U of Illinois Division of Research Safety.
• Globally Harmonized System at MilliporeSigma (Sigma-Aldrich), a major chemical supplier, includes some nice timeline and country data.

See also: ACGIH, ANSI, CFR, Hazard Statements, Precautionary Statements, risk phrases, safety phrases, UN/NA Numbers.

Additional definitions from Google and OneLook.

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Disclaimer: The information contained herein is believed to be true and accurate, however ILPI makes no guarantees concerning the veracity of any statement. Use of any information on this page is at the reader's own risk. ILPI strongly encourages the reader to consult the appropriate local, state and federal agencies concerning the matters discussed herein.