GHS Globally Harmonized System of Classification and Labelling of Chemicals

GHS Globally Harmonized System of Classification and Labelling of Chemicals

GHS Globally Harmonized System

Introduction to GHS

The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) was established with the mandate of creating a globally harmonized hazard classification and compatible labelling system, along with standardized material safety data sheets (MSDS) and easily understandable symbols. The United Nations Sub-Committee of Experts on the Globally Harmonized System of Classification and Labelling of Chemicals (UNSCEGHS) is responsible for the development and maintenance of GHS. It is not legislation, but is the framework applied to make legislation in regions all over the world and used by other rules such as transport of hazardous products.

Purpose: GHS aims to provide a consistent method for assessing the hazards of chemicals and mixtures, as well as communicating these hazards effectively. It allows for a globally agreed-upon approach to assigning label elements, describing hazards using consistent language, and applying hazard labels to products.

Global Audience: GHS is intended for a global audience, and each region can adopt GHS into its own legislation. Many regions around the world have already implemented GHS into their regulatory frameworks.

GHS provides flexibility for regions to adopt and implement the rules according to their specific requirements regarding labelling and supply of safety data sheets (SDS). This flexibility accommodates existing regulatory systems and allows for adaptation to regional needs.

Scope: GHS covers the classification and communication of hazards for substances, including chemicals and natural complex substances (NCS), as well as mixtures such as flavours, fragrances, paints, and coatings. It also is the key legislation which deals with Safety Data Sheets (SDS), therefore the scope in many regions extends to any mixture which can be supplied to a business or professional user for which a SDS is required.

GHS is a dynamic system that evolves over time. As new scientific information becomes available and as international consensus changes, GHS is modified accordingly. This means that global regional legislation adopting GHS will also change in response to updates to the system. A recent example is Endocrine Disrupting Chemicals (EDC’s).

GHS and Safety: GHS primarily focuses on the classification of hazards based on intrinsic properties of substances or mixtures e.g. is the substance flammable, is it acutely toxic, is it environmentally hazardous. By informing users about these hazards, this allows them take appropriate precautions to minimize risks associated with exposure to people or the environment, both in normal use and accidental release. The key methods of informing users are through information in SDS and labels.

It is common for a single substance or mixture to have multiple hazards and corresponding precautions. For example, a chemical may be irritating to the eyes, irritating to the skin, and hazardous to the aquatic environment, each requiring its own set of hazard communication elements.

Overall, GHS plays a crucial role in promoting global consistency in hazard classification and communication, thereby enhancing safety in the handling, use, and transportation of chemicals worldwide.

More information about GHS can be found on the UNECE website:

GHS Hazard Communication

GHS hazard communication is essential for ensuring the safe handling, use, and transportation of chemicals. It provides crucial information to various stakeholders, including workers, emergency responders, and the general public, to help them understand and mitigate the risks associated with hazardous substances.

The different elements of GHS hazard communication are:

Signal Word: A word used to indicate the severity of the hazard. The two signal words used in GHS are “Danger” and “Warning,” with “Danger” indicating more severe hazards.

Pictogram: A graphical symbol contained within a red diamond, providing a visual warning of the hazard. There are nine possible pictograms in GHS, each representing a specific type of hazard, such as corrosive, flammable, or environmental hazard.

Hazard Statement: A standardized phrase that describes the nature of the hazard associated with the substance or mixture. Hazard statements provide concise information about the potential risks posed by the chemical.

Precautionary Statements: Recommended measures to minimize or prevent adverse effects resulting from exposure to the hazardous substance or mixture. Precautionary statements include guidance on safe handling, storage, disposal, and personal protective equipment.

How to classify according to GHS

GHS classification of a substance involves three fundamental steps:

1.Obtain Relevant Data: Gather relevant data about the substance, including information about its chemical composition, physical properties, toxicological effects, and environmental impact.

2.Review Data Compared to GHS Criteria: Review the collected data against the criteria outlined in the GHS to determine the appropriate hazard classification.

3.Assign GHS Classification Elements: Based on the review of data and comparison to GHS criteria, assign the appropriate GHS classification elements, including signal words, pictograms, hazard statements, and precautionary statements.

GHS classification of mixtures such as formulations can use the same criteria as for substances but more typically calculation methods are used. There are specific rules in GHS about the methods and how to classify mixtures, which also relate to the type of hazard and its severity. Some examples of calculation methods are:

Additivity Method for Skin Corrosion and Irritation

The classification of mixtures is calculated based on the cumulative effect of corrosive or irritant ingredients present in the mixture. This method considers the dosage and potency of hazardous ingredients.

Relevant Ingredients: Ingredients present at or above the generic cut-off (1% for skin corrosion/irritation) are considered relevant. However, GHS acknowledges that ingredients below this level may still be relevant, especially corrosive ingredients.

Weighting Factor: Corrosive ingredients present at concentrations below the classification limit for Category 1 are assigned a weighting factor of ten. This means that corrosive ingredients at concentrations as low as 0.1% can contribute to the classification of the mixture as an irritant.

Classification Criteria: A mixture is classified as corrosive or irritant to the skin when the sum of the concentrations of relevant ingredients exceeds the cut-off value or concentration limit.

These principles ensure that even small concentrations of corrosive ingredients can impact the overall classification of mixtures, emphasizing the importance of considering all relevant ingredients when assessing skin corrosion/irritation hazards. Formpak performs these calculations.

Summation Method for Acute Aquatic Environmental Toxicity

This is a cumulative method, and each environmentally hazardous ingredient contributes to the overall hazardous properties of the mixture. The overall effect is determined by the dosage and potency of the relevant hazardous ingredients.

Relevant Ingredients: Ingredients present at or above the generic cut-off levels are considered relevant. These cut-off levels vary depending on the category of aquatic environmental hazard.

M Factors: M factors serve as a multiplying factor for highly hazardous components for which Category 1 standard behaviour is inadequate.

Tiered Approach: Classification is conducted in a tiered approach. First, Category 1 substances are considered. If the total concentration of relevant Category 1 materials is 25% or more, the Category 1 classification criteria are met. If not, the criteria for Category 2 substances are considered, and so on.

This approach ensures that all relevant ingredients are taken into account when assessing the environmental hazards of mixtures, with a focus on both the concentration and the potency of hazardous components. Formpak performs these calculations.


A key message for compliance is each person or company in the supply chain is responsible for providing information on hazardous products it supplies to others, typically on hazard labels and in Safety Data Sheets. Formpak produces GHS SDS and Labels, including for regional rules.

Common GHS Hazards

Flammable Liquid

Criteria: Flashpoint of 93°C or below with different categories based on flashpoint and initial boiling point. Accompanied by Flame pictogram and a hazard phrase, for example for category 2 “Highly flammable liquid and vapour”.

Skin Corrosion/Irritation

Skin corrosion: Irreversible damage; accompanied by “Causes severe skin burns and eye damage” hazard phrase and Corrosion pictogram.

Skin irritation: Reversible damage; accompanied by “Causes skin irritation” hazard phrase and Exclamation pictogram.

Serious Eye Damage/Eye Irritation

Serious eye damage: Irreversible tissue damage. “Causes serious eye damage ” hazard phrase and Corrosion pictogram.

Eye irritation: Reversible changes in the eye; accompanied by “Causes serious eye irritation” hazard phrase and Exclamation pictogram.

Skin Sensitization

Allergic response after skin contact; can be categorized into 1A, 1B, or 1; accompanied by “May cause an allergic skin reaction” hazard phrase and Exclamation pictogram.


Severe acute effects if swallowed and enters airways; accompanied by “May be fatal if swallowed and enters airways ” hazard phrase and Health Hazard pictogram.

Hazardous to the Aquatic Environment:

There are several categories based on acute and chronic effects on aquatic life. There are multiple hazard statements, relating to severity of the hazard including “Very toxic to aquatic life with long lasting effects” accompanied by the Dead fish dead tree pictogram.

Other GHS Hazards

There are other physical hazards in GHS, such as explosive. There are also many other health hazards including the following:

Acute Toxicity – How toxic (poisonous) a substance based on the three different routes of exposure Oral, Dermal and Inhalation. There are 5 Categories based on severity of health effects.

Specific Target Organ Toxicity – These capture more specific toxic effects on organs not addressed by other hazards.

CMR hazards are:

  • Carcinogenicity: potential to induce or increase the incidence of cancer.
  • Germ Cell Mutagenicity: Heritable gene mutations (mutations which can be transferred to offspring).
  • Reproductive Toxicity: Adverse effects on sexual function and fertility.

Formpak performs GHS and regional calculations and assigns appropriate elements including hazard and precautionary statements. Additionally, Formpak can be configured to automatically update existing products based on changes, for example, to compositions and hazardous component classification changes.


March 2024

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