Hazard symbols and their meanings

Hazard symbols and their meanings

Written by Dina Adlouni

Published July 9, 2024

From Hazard to Harmony: Uncovering the Significance of Hazard Pictograms

From toxic chemicals to flammable substances, hazardous products can be dangerous to your employees and the environment. It’s important you understand hazard pictograms and exactly what they mean to protect your people from short or long-term health hazards and surrounding environments from harm. This can keep employees who are working with these substances safe and help you, as the employer, mitigate risks faster with the proper training, controls, and processes in place.  

Keep reading to uncover: 

  • Chaos to Clarity: How the GHS simplifies the labelling of chemicals 
  • What type of hazards do the standard pictograms represent 
  • How you can elevate your chemical management approach to protect your people

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Chaos to Clarity: How the GHS Simplifies the Labelling of Chemicals

You might be thinking, what is GHS? GHS or the Globally Harmonized System of Classification and Labelling of Chemicals, is an international standard that is used to classify hazards and label hazardous chemicals. Hazard pictograms must be included on the label of a chemical product, as a requirement under the GHS. This standardized system provides a single source of truth so people can fully understand the risks certain substances pose, just by looking at the pictogram.  

What Type of Hazards do the Standard Pictograms Represent?


There are 9 standard pictograms which are used to depict potential hazards worldwide. Each black symbol is depicted within a red diamond with a white background. It is your responsibility as the employer that all employees are trained and taught how to recognize each of the pictograms if they work with hazardous substances.  

You can find an example of each below:  

Images of all the GHS pictograms. Black hazard symbols in read diamonds for warning

Now, let’s get into more detail about exactly what these hazardous symbols mean: 

1. Gas under pressure

Gas under pressure hazard pictogram

This hazard pictogram indicates gases which are stored under pressure, such as ammonia. The symbol depicts a gas cylinder because this is a common example of something that is found at certain organizations. To protect your employees, make sure these cylinders are always checked to avoid a potential leak.   

2. Dangerous for the environment

Dangerous for the environment hazard pictogram

Showing an environment with chemicals that are harmful to species living in water, this pictogram indicates substances which are dangerous for the environment. Make sure all employees carefully use chemicals with this label and dispose of them in the proper way.  

3. Toxic

Toxic hazard pictogram

The skulls and crossbones is a familiar symbol to most of us, as this is used to indicate something that is toxic if ingested, inhaled, or absorbed. Provide the proper training on such chemicals so employees are aware and can take the proper steps to avoid harm.  

4. Health hazard 

Health hazard hazard pictogram

In addition to toxic substances, there are several which can cause health hazards irritating the skin and eyes, respiratory tract, and more. This pictogram shows a picture of an exclamation mark. Health hazards are a serious risk to your people, so ensure they all are trained to properly use such chemical products and are given the necessary personal protective equipment.  

5. Flammable

Pillar - SDS - Blog - GHS pictogram 02

This pictogram shows a flame which means this substance is flammable. Substances that can ignite or catch on fire can be very dangerous to your teams, so provide training on how to deal with these products.  

6. Oxidizing

Oxidizing hazard pictogram

This pictogram, showing a circle which appears to be on fire, indicates that this chemical product can react with others and release oxidizing substances. This is dangerous because such chemicals can cause fires or explosions.   

7. Explosives

Pillar - SDS - Blog - GHS pictogram 01

Chemical products that have the potential to explode can cause serious risks to your employees. This pictogram shows a bomb exploding, so it’s up to you to provide the necessary training to employees so they know how to handle such a substance.   

8. Serious health hazard

Serious health hazard hazard pictogram

Certain substances have the potential to cause serious damage to the health of your people. This pictogram, showing someone with internal damage, is usually found on chemical products that can affect internal organs, fertility, and more. 

9. Corrosive

Corrosive hazard pictogram

Chemicals that can be extremely harmful to your skin or objects around you are labelled corrosive. This pictogram depicts skin and specific materials that are damaged because of this substance. All employees must learn how to properly use such products and be given the necessary PPE.  


Elevate Your Chemical Management Approach to Protect Your People

With a multitude of harmful substances in the world, it can be difficult to properly shield your employees from all the dangers they may pose.  

 EcoOnline can help you manage chemicals and create safer workplaces to protect your employees from potential hazards. From safety data sheet management, authoring SDS software, risk assessments, and more, our cloud-based chemical management solution houses all your chemical needs in one platform. Easily access and distribute all information and data to your teams with the click of a button and maintain compliance within your industry and region.  

Eager to level up your chemical management approach? Check out our solution.

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Author Dina Adlouni

Dina is a Content Marketing Manager at EcoOnline. She has been a content writer for eight years and has been writing about health and safety for the past three years. 

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