In this guide, we’ll shed light on the various chemical label classification systems that exist. The goal is to provide manufacturers and product managers with the knowledge to make better purchasing and planning decisions with chemical label printing design and procurement.

Chemical labels play a critical role in safety and informing users about the hazards and proper handling of substances. Yet the array of symbols, numbers, pictograms, and abbreviations can be overwhelming without a thorough understanding of the classification systems. If a product isn’t properly classified, their label will be out of compliance. This opens manufacturers up to all sorts of regulatory and legal issues, as well as consumer trust blowback.

With expert insights and explanations, buyers of product labels (also called prime labels) can get a clear understanding of the most used classification systems, such as the Globally Harmonized System (GHS) and the European Union Classification, Labeling, and Packaging Regulation (CLP), among others. We’ll discuss the criteria used to categorize and identify hazards, enabling readers to confidently interpret and comply with chemical label regulations and avoid label printing pitfalls.

The Importance of Chemical Labels and the Role of Prime Label Classification

Chemical labels serve as vital communication tools by providing essential information about the hazards and safe handling of substances. Accurate prime labels protect the health and safety of workers, consumers, and the environment. Properly labeled chemical products help users understand the potential risks and take appropriate precautions. Without correct labeling, individuals may unknowingly expose themselves to harmful substances, leading to accidents, injuries, or even long-term health issues. Additionally, chemical labels play a role in regulatory compliance, ensuring that products are labeled according to established country and global standards. By understanding the role of chemical label classification, manufacturers and product managers can make informed label purchasing decisions as they prioritize safety and compliance.

Chemical label classification systems are designed to standardize how hazards are identified and communicated. These systems provide a framework for categorizing chemicals based on their physical, health, and environmental hazards. By assigning specific labels and symbols to different hazard classes, classification systems simplify the identification and communication of potential risks. The result is that users can quickly and accurately understand the hazards associated with a particular chemical product. Label classification systems also streamline compliance with regulatory requirements, as they provide clear guidelines for labeling and hazard communication.

Label classification systems also play a role in supply chain management and procurement decisions. By understanding the classification requirements for different chemical products, manufacturers and product managers can ensure that they are sourcing and using the appropriate labels. This knowledge helps prevent labeling errors, reduces the risk of non-compliance, and saves both time and resources. With a solid grasp of label classification systems, manufacturers can confidently handle the label printing procurement process, ensuring that their products are properly labeled and compliant with relevant regulations.

Overview of the Globally Harmonized System (GHS)

The Globally Harmonized System (GHS) is a globally recognized classification and labeling system for chemicals. It was developed by the United Nations to standardize hazard communication worldwide. The GHS aims to harmonize the classification criteria, label elements, and safety data sheet (SDS) requirements for chemicals across different countries and regulatory systems. By adopting the GHS, countries ensure consistent hazard communication and facilitate the safe use, transport, and trade of chemicals.

The GHS employs a hazard-based approach to classification, focusing on the intrinsic properties of chemicals and their potential to cause harm. It categorizes chemicals into different hazard classes, such as flammable liquids, corrosive substances, or carcinogens. Each hazard class is assigned a specific label element and pictogram that provides a visual representation of the associated hazard. The GHS also includes standardized signal words, hazard statements, and precautionary statements, which further enhance hazard communication and understanding.

You can get a copy of the latest GHS publication here.

Key Elements of GHS Chemical Labels

GHS chemical labels contain several key elements that convey important information about the hazards and safe handling of substances. Hazards are classified by thirty-three hazard classes and three hazard categories.

Globally Harmonized System (GHS) Hazard Classes


Pyrophoric solids

Respiratory sensitization


Self-heating substances and mixtures

Skin sensitization


Substances and mixtures, which in contact with water, emit flammable gases

Germ cell mutagenicity


Oxidizing liquids


Chemicals under pressure

Oxidizing solids

Reproductive toxicity

Oxidizing gases

Organic peroxides

Specific target organ toxicity - single exposure

Gases under pressure

Corrosive materials

Specific target organ toxicity - repeated exposure

Flammable liquids

Desensitized explosives

Aspiration hazard

Flammable solids

Acute toxicity

Hazardous to the aquatic environment, short-term (acute)

Self-reactive substances and mixtures

Skin corrosion/irritation

Hazardous to the aquatic environment, long-term (chronic)

Pyrophoric liquids

Serious eye damage/eye irritation

Hazardous to the ozone layer

GHS Hazard Categories

There are three broad hazard categories:

  • Physical hazards
  • Health hazards
  • Environmental hazards

Once the product is categorized according to the classes and categories above, the following six elements are added to the chemical label. These elements guarantee consistent labeling across different countries and facilitate the identification of potential risks. Understanding these key elements is important at every stage of the supply chain from manufacturers and product managers to the consumer.

1. Product Identifier

The product identifier is a unique name or number assigned to a chemical product. It helps identify the specific substance or mixture and ensures accurate communication of hazards.

2. Signal Word

The signal word appears prominently on the product label and indicates the severity of the hazard. The GHS uses two signal words: “Danger” for more severe hazards and “Warning” for less severe hazards.

3. Hazard Statements

Hazard statements describe the nature and degree of the hazards associated with a chemical product. They provide concise information about the primary hazards, such as “May cause cancer” or “Flammable liquid and vapor.”

4. Precautionary Statements

Precautionary statements provide practical advice on how to safely handle, store, or dispose of a chemical product. They help users take appropriate precautions to minimize risks and prevent accidents.

5. Pictograms

Pictograms are standardized symbols that visually represent the hazards associated with a chemical product. The GHS uses nine pictograms, each associated with a specific hazard class. These pictograms provide a quick and easily understandable indication of the potential risks. Samples of various pictograms are illustrated below.

6. Supplier Identification

GHS labels also include information about the supplier or manufacturer of the chemical product. This allows users to contact the responsible party for additional information or in case of an emergency.

Example of GHS Chemical Labels

The following is an example chemical label arrangement for a Category 2 flammable liquid.

The outer packaging has a flammable liquid transport label.

The inner plastic bottle has a GHS hazard warning label with required elements.

Examples of GHS chemical label elements

Image source – Globally Harmonized System of Classification and Labeling of Chemicals (GHS) – Tenth revised edition, 2023

Hazard Communication and Product Labeling Requirements in the US and Other Countries

While the GHS is widely adopted and recognized, other classification systems exist in different regions and countries. These systems may have specific requirements and symbols that differ from the GHS. Label buyers and designers need to be aware of these differences to ensure compliance with the relevant labeling regulations.

One such system is the European Union Classification, Labeling, and Packaging Regulation (CLP). CLP is based on the GHS, but it includes additional hazard classes and categories specific to the European Union. Manufacturers exporting to the EU must comply with the CLP requirements, which include specific labeling and classification criteria.

In the United States, OSHA has the Hazard Communication Standard: Labels and Pictograms (HCS) for proper labeling of chemical containers.

Detailed information on OSHA’s HCS can be found here.

OSHA programs ensure that employees are aware of the hazards associated with the chemicals they work with and have access to the necessary information to protect themselves. Labeling requirements may vary depending on the specific regulatory framework, but they typically involve the use of standardized labels, symbols, and hazard statements.

Example of OSHA HCS Label

OSHA 3492 quick card showing HCS for chemical label

In addition to labeling requirements, hazard communication programs also involve the provision of safety data sheets (SDS) for chemical products. They used to commonly be known as material safety data sheets (MSDS) and are often still labeled as such. But MSDS are less standardized than the globally recognized SDS.  With the transition to the GHS, manufacturers are transitioning to the SDS to meet international standards.

SDSs provide detailed information about the physical and chemical properties of substances, their hazards, safe handling procedures, and emergency response measures. Together with properly labeled containers, SDSs help ensure that workers have the information they need to work safely with chemicals.

Also in the US, the Department of Transportation (DOT) has their own requirements that may affect chemical product labeling for transport.

A copy of the DOT’s Hazardous Materials Markings, Labeling and Placarding Guide can be downloaded here.

The full code of federal regulations regarding transportation of hazardous materials is here.

It’s also important to note that some regulatory agency requirements may overlap. For example, OSHA says,

“It is important to note that the OSHA pictograms do not replace the diamond-shaped labels that the U.S. Department of Transportation (DOT) requires for the transport of chemicals, including chemical drums, chemical totes, tanks or other containers.”

Understanding the similarities and differences between these classification systems is a necessary step for companies that operate in multiple regions or countries.

Common Chemical Label Symbols and Their Meanings

As we mentioned earlier, chemical labels often include symbols or pictograms that represent specific hazards associated with a substance. These symbols provide a quick and easily recognizable visual representation of the potential risks.

OSHA Hazard Pictograms

OSHA has nine hazard communication pictograms, explained briefly below.

Designers can download high-resolution HCS pictograms here.

9 OSHA hazard pictograms

1. Flame

The flame symbol indicates that the substance is flammable, meaning it can easily catch fire or ignite.

2. Skull and Crossbones

The skull and crossbones symbol represents substances that are acutely toxic and can cause severe harm or even death.

3. Corrosion

The corrosion symbol depicts a flask dissolving or corroding, indicating that the substance can cause damage to metals, skin, or other materials it contacts.

4. Exclamation Mark

The exclamation mark symbol signifies substances that may cause irritation, sensitization, or other less severe health effects.

5. Environment

The environment symbol represents substances that can harm aquatic life or have other adverse effects on the environment.

6. Gas Cylinder

The gas cylinder symbol indicates substances that are compressed or liquefied gases, which can be hazardous due to their pressure or reactivity.

7. Health Hazard

The health hazard symbol represents substances that can cause long-term health effects, such as carcinogens, infectious agents, genetically modified organisms, or reproductive toxins.

8. Exploding Bomb

The exploding bomb symbol signifies substances that are explosive or have explosive properties.

9. Flame Over Circle

The biohazard symbol represents oxidizers which are chemicals that facilitate burning.

GHS Hazard Pictograms

The GHS has about 29 pictograms for the labeling of chemicals used for the various GHS classes and categories.

GHS hazard pictograms for labels

Designers and printers can download high resolution GHS pictograms here.

Understanding these common chemical label symbols helps workers and consumers to quickly identify potential hazards and take appropriate precautions.

Expanded Content Labels (Booklet Labels) for Hazardous Chemicals

With the many label requirements for usage instructions, warnings, additional languages, disclaimers, and hazard information, the expanded content label, also called a booklet label (shown below), offers a good way to present all of it.

booklet label on package

For example, a chemical product shipping to various countries can accommodate all the languages in a single expanded content label. It avoids the need to print different labels for each country.

Some bottled garden pesticide products and bottled fertilizers often require this type of product label to satisfy the many governmental requirements for labeling.

Summary: The Importance of Proper Chemical Product Labels for Safety and Compliance

Proper chemical product labels are designed and regulated to ensure safety and compliance in various industries around the world. They play a critical role in communicating hazards, guiding safe handling practices, and facilitating regulatory compliance for manufacturers and consumers.

By following established label classification systems such as the Globally Harmonized System (GHS), the European Union Classification, Labeling, and Packaging Regulation (CLP), as well as OSHA and DOT labeling requirements, companies can provide accurate and consistent labeling across different markets. This reduces the risk of non-compliance, improves safety, and facilitates international trade. Classifications help product managers make informed decisions when procuring label printing services.

For end-users, proper chemical product labels provide vital information about potential risks, safe handling procedures, and emergency care. Proper chemical labeling lets individuals protect themselves and others from accidents, injuries, and long-term health issues.

Helpful Links – Chemical Labels Classification Systems

Below is a list of the helpful links from this article and elsewhere on our site.

Where to Get Chemical Labels in California

An experienced prime label supplier like Clear Print can assist with chemical label design and printing. Their more than four decades of award-winning label printing and design experience are there for clients to lean on. They offer a wide range of durable sustainable label materials and adhere to eco-friendly print production processes. They are well-known for their #1 On-Time Delivery record of never missing a fixed deadline in more than 20 years, as shown by their numerous client reviews.

Type of Product Labels (Prime Labels) Available from Clear Print

A few of the types of prime labels that Clear Print helps clients design and print include:

  • Paint labels
  • Swimming pool chemical labels
  • Fertilizer labels
  • Lawn and garden care labels
  • Pest control product labels
  • Mold and fungus control product labels
  • Industrial cleaner labels
  • Household cleaner labels
  • Cleaning agent labels

The team at Clear Print is always available to discuss a company’s label printing needs. There are 3 ways to get in touch:

1 – Go here to send specs on your latest label project and someone will reply as soon as possible.

2 – Call 818-709-1220 to speak with a folding carton advisor.

3 – Email or use the Contact Us form.

Published On: April 15th, 2024 / Categories: Labels /