GHS – Globally Harmonized System of Classification and Labeling

GHSpicThe GHS is a system for standardizing and harmonizing the classification and labelling of chemicals. It is a logical and comprehensive approach to:

  • Defining health, physical and environmental hazards of chemicals;
  • Creating classification processes that use available data on chemicals for comparison with the defined hazard criteria; and
  • Communicating hazard information, as well as protective measures, on labels and Safety Data Sheets (SDS).

The GHS covers all hazardous chemicals. There are no complete exemptions from the scope of the GHS for a particular type of chemical or product. The term “chemical” is used broadly to include substances, products, mixtures, preparations, or any other terms that may be used by existing systems. The goal of the GHS is to identify the intrinsic hazards of chemical substances and mixtures and to convey hazard information about these hazards.

In the workplace, it is expected that most of the GHS elements will be adopted, including

  • GHS physical and health hazard criteria, as appropriate;
  • Labels that have the harmonized core information under the GHS (signal words, hazard statements and symbols, etc.);
  • Safety Data Sheets;
  • Employee training to help ensure effective communication is also anticipated.

Classification is the starting point for hazard communication. It involves the identification of the hazard(s) of a chemical or mixture by assigning a category of hazard/danger using defined criteria.

The GHS physical hazards are listed below. For many of the physical hazards the GHS Document contains Guidance Sections with practical information to assist in applying the criteria:

  • Explosives;
  • Flammable Gases;
  • Flammable Aerosols;
  • Oxidizing Gases;
  • Gases Under Pressure;
  • Flammable Liquids;
  • Flammable Solids;
  • Self-Reactive Substances;
  • Pyrophoric Liquids;
  • Pyrophoric Solids;
  • Self-Heating Substances;
  • Substances which, in contact with water emit flammable gases;
  • Oxidizing Liquids;
  • Oxidizing Solids;
  • Organic Peroxides;
  • Corrosive to Metals.

The GHS Health and Environmental Hazards criteria represent a harmonized approach for existing classification systems:

Health Hazard:

  • Acute Toxicity;
  • Skin Corrosion/Irritation;
  • Serious Eye Damage/Eye Irritation;
  • Respiratory or Skin Sensitization;
  • Germ Cell Mutagenicity;
  • Carcinogenicity;
  • Reproductive Toxicology;
  • Target Organ Systemic Toxicity – Single Exposure;
  • Target Organ Systemic Toxicity – Repeated Exposure;
  • Aspiration Toxicity.

Environmental Hazard:

  • Hazardous to the Aquatic Environment
    • Acute aquatic toxicity;
    • Chronic aquatic toxicity;
      • Bioaccumulation potential;
      • Rapid degradability.

GHS approach to classifying mixtures

For consistency and understanding the provisions for classifying mixtures, the GHS defines certain terms. These working definitions are for the purpose of evaluating or determining the hazards of a product for classification and labeling.

Substance: Chemical elements and their compounds in the natural state or obtained by any production process, including any additive necessary to preserve the stability of the product and any impurities deriving from the process used, but excluding any solvent which may be separated without affecting the stability of the substance or changing its composition.

Mixture: Mixtures or solutions composed of two or more substances in which they do not react.

Alloy: An alloy is a metallic material, homogeneous on a macroscopic scale, consisting of two or more elements so combined that they cannot be readily separated by mechanical means. Alloys are considered to be mixtures for the purpose of classification under the GHS.

Where impurities, additives or individual constituents of a substance or mixture have been identified and are themselves classified, they should be taken into account during classification if they exceed the cutoff value/concentration limit for a given hazard class.

As mentioned previously, the GHS physical hazard criteria apply to mixtures. It is assumed that mixtures will be tested for physical hazards. Each health and environmental endpoint chapter in the GHS contains specific criteria for classifying mixtures as well as substances. The GHS Document or “Purple Book” should be consulted for complete information on classifying mixtures.

Hazard Communication

Once a chemical has been classified, the hazard(s) must be communicated to target audiences. As in existing systems, labels and Safety Data Sheets are the main tools for chemical hazard communication. They identify the hazardous properties of chemicals that may pose a health, physical or environmental hazard during normal handling or use. The goal of the GHS is to identify the intrinsic hazards found in chemical substances and mixtures, and to convey information about these hazards.

The international mandate for the GHS included the development of a harmonized hazard communication system, including labelling, Safety Data Sheets and easily understandable symbols, based on the classification criteria developed for the GHS.

Glossary of Label Elements Included in GHS
Elements of GHS
Globally Harmonized System (GHS) specifies certain elements that should appear together on chemical labels. Like the current pesticide labeling system, hazard statements, pictograms (symbols), and signal words may be required on pesticide labels depending on the toxicity or hazards of the product, while precautionary statements, product identifiers, and supplier information are required on all labels. As some elements would change, EPA recognizes that GHS implementation will require extensive outreach, education and training to promote understanding of the new labels.

  • Hazard statement(s): Phrase assigned to each hazard category that describes the nature of the hazard. Examples of hazard statements are: “Harmful if swallowed,” “Highly flammable liquid and vapor” and “Harmful to aquatic life.” GHS hazard statements are based in part on current EPA requirements and are generally very similar, but there are some differences.
  • pictogramPictogram(s): A symbol inside a diamond with a red border, denoting a particular hazard class (e.g., acute toxicity/lethality, skin irritation/corrosion, etc.). Five of the GHS pictograms would appear most often on pesticide products.
  • Precautionary statement(s): Phrases that describe recommended measures that should be taken to minimize or prevent adverse effects resulting from exposure to a hazardous product, or improper storage or handling of a hazardous product. These phrases cover prevention, response, storage, and disposal of products. GHS provides guidance on precautionary statements and includes a list of statements that may be used. These statements are similar to the precautionary statements that EPA currently uses. Work to increase standardization of precautionary statements may be undertaken in the future.
  • Product identifiers: Names or numbers used on a hazardous product label or in a safety data sheet. They provide a unique means by which the product user can identify the chemical substance or mixture. Under the GHS, labels for substances should include the chemical identity of the substance. Labels for mixtures should include the identities of the ingredients that are responsible for certain hazards on the label, except that regulatory authorities may establish rules for protection of Confidential Business Information that preclude ingredient disclosure. (The hazard information would still appear on the label even if the ingredients are not named.) Current EPA requirements for product identifiers are consistent with GHS.
  • Signal word: One word used to indicate the relative severity of hazard and alert the reader to a potential hazard on the label and safety data sheet. The GHS includes two signal words:

“Warning” for less severe hazard categories and;

“Danger” for more severe hazard categories.

Lower categories of classification and unclassified products would not require pictograms or signal words under GHS. The current EPA system includes a third signal word “Caution” which is used in addition to “Warning” and “Danger.”

  • Supplier identification: Under the GHS supplier identification would include the name, address and telephone number of the manufacturer or supplier of the substance. Current EPA requirements for product identifiers are generally consistent with GHS. EPA encourages but does not require telephone contact numbers on pesticide labels.

Aspects of Pesticide Regulation that GHS Does Not Affect
Implementing GHS would not change most aspects of the pesticide program. It would not affect supplemental information on labels (such as directions for use and additional hazard information, as long as the information does not contradict or detract from GHS label information), testing methods for health and environmental hazards, data requirements, the scope of hazards covered, policies governing the protection of Confidential Business Information (CBI), or risk management measures.

Pictograms and their Benefits
Elements of GHS

Currently, EPA uses two pictograms: a version of the skull and crossbones for the most severe categories of acute toxicity and a flame symbol for certain highly flammable total release foggers. The Globally Harmonized System (GHS) includes a number of additional pictograms.

The complete set of GHS pictograms can be viewed on the United Nations GHS Web site.  EPA anticipates that the pictograms below would be the most commonly used on pesticide labels. For more information on the hazard class and criteria of each category, please click on the pictogram.