Hazard symbols and labelling for chemicals
Chemicals are a natural part of everyday life in many companies – from industrial production and laboratories to construction sites and agriculture. With chemicals also comes a responsibility: to protect employees, customers and the environment. That is why you see the little red hazard symbols on bottles, containers and safety data sheets.
Here we go through what the hazard symbols mean, how they should be handled in practice, and what laws and regulations apply.
What is a hazard symbol?
A hazard symbol (also known as a hazard pictogram and hazard label) is a pictorial icon that highlights the risk of chemicals that may expose the user to health, environmental, fire or explosion hazards. The hazard symbols are designed to be understandable for everyone. In other words, you don’t need to know chemistry to understand that a picture of a flame means “flammable”. This makes it easy to identify potential hazards, regardless of situation and language.
Where are the hazard symbols located?
The hazard symbols must be clearly marked on the product being used, and can be found on the packaging or in the safety data sheet (SDS). Sometimes the workplace may also have its own lists of hazard symbols on cabinets, containers or other storage areas, for example when storing chemicals in large quantities.
What do the hazard symbols mean?
Previously, orange hazard symbols were used, but from 2015 these were replaced by red and white diamonds. Each symbol represents a specific type of chemical hazard:
Acute toxicity
May cause life-threatening injuries if swallowed, in contact with skin or inhaled.
Corrosive
May cause burns to skin and eyes or serious eye damage. Also used for chemicals that may be corrosive to metals.
Health hazard
May cause irritation to the skin, eyes and respiratory tract, allergic skin reactions, drowsiness and dizziness.
Chronic health hazard
May cause cancer, genetic damage, reduced fertility, birth defects, inhalation allergy, chemical pneumonia or other serious health effects.
Environmental hazard
Can be acute or long-term toxic, and/or cause long-term damage because the substance is persistent and bioaccumulative. Must be handled so that the product, either in use or as waste, does not harm nature.
Explosive
May explode on impact, friction, sparks or heat.
Oxidising
May cause fire or contribute to the combustion of other materials.
Flammable
Can ignite easily and burn violently. Some chemicals produce flammable gas in contact with water or self-ignite in air.
Gas under pressure
Container with pressurised gas or extremely low temperature. May explode in case of external fire.
How to handle hazard symbols?
Hazardous chemicals must be labeled with a hazard label that provides information about hazards and necessary precautions. Among other things, the label must contain a hazard symbol, warning words and hazard and safety phrases (H and P phrases).
If you notice a hazard symbol on a product, you must take extra precautions. This may involve:
- Always read the hazard label before use
- Check SDS for more information
- Follow the instructions carefully
- Use the right protective equipment
- Ensure sufficient ventilation
- Avoid mixing incompatible chemicals
- Wash hands, clothes and equipment thoroughly after use
- If swallowed or poisoned, contact poison control or emergency services
International laws and regulations
Most European countries follows the CLP regulation (Classification, Labelling, and Packaging), which is based on the global system GHS (Globally Harmonized System and Classification and Labelling of Chemicals). CLP ensures that chemical hazards are clearly communicated through standardized symbols, signal words, and safety statements. In addition, the REACH regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals) also applies within the European Union.
Outside the EU, many countries have implemented or are aligning with GHS-based classification and labelling systems. However, the specific regulatory frameworks, registration requirements, and enforcement practices vary between jurisdictions.
Companies must therefore ensure compliance with the applicable chemical control legislation in each country where their products are manufactured, imported, distributed, or used.
Important: In addition to regional frameworks, national and local regulations may apply. Individual countries may have supplementary requirements related to storage, transport, workplace safety, environmental protection, or reporting obligations. It is essential to verify compliance with all applicable laws in the relevant market.
Hazard symbols are not just little red icons on a label. They are the key to understanding and following chemical regulations. When employees know the symbols, read the labels and follow the instructions, they contribute to a safer working day in line with national and international requirements.
In addition, the hazard symbols provide a common recipe for how chemicals should be described and labeled, no matter where in the world they are used. This makes communication easier, provides a better overview in the workplace and ensures that everyone speaks the same “language” about chemicals.
