Making COSHH symbols clear and accessible in your D&T classroom 

Published 27th November 2025

Understanding the risks associated with chemicals is an essential part of keeping a design and technology classroom safe. COSHH (Control of Substances Hazardous to Health) symbols provide a simple, recognisable way to identify potential dangers. For D&T teachers, these symbols are not just a regulatory requirement, they are a practical tool to help students develop safe working habits and a deeper awareness of materials. 

From flammable solvents to toxic adhesives, recognising hazards is the first step in creating a secure learning environment. COSHH symbols cover a range of risks, including: 

• Harmful to the environment: Substances that are dangerous to  wildlife and water life, such as being highly toxic to marine life with long-lasting effects. 

• Flammable: Substances that ignite on contact with air, a small ignition source, have a flash point of 60⁰C or below, or can evolve highly flammable gases when in contact with water. 

• Explosives: Solid or liquid substances that, by chemical reaction, can produce gas at such a speed, temperature, and pressure that it can damage its surroundings. 

• Oxidising: Substances that are not necessarily combustible in themselves but which may cause or contribute to the combustion of other materials by providing oxygen. The combustion is often exothermic and can be vigorous enough to cause explosions. 

• Toxic: Substances which can cause harm if inhaled, ingested, or absorbed through the skin. 

• Health hazard: Anything that may cause harm to a person's health – this could include solid materials, chemicals, dusts, fumes, and biological agents. 

• Serious health hazard: Substances that can cause severe, long-term, or fatal health problems, even with minimal exposure. This includes substances that cause cancer or genetic defects, as well as those that cause severe immediate harm like permanent blindness or damage to internal organs. 

• Gas under pressure: Any gas at a pressure greater than 0.5 bar above atmospheric pressure. This includes compressed, liquefied, and dissolved gases, most commonly stored in gas cylinders. 

• Corrosive: Can cause severe skin burns and eye damage as well as being corrosive to metals. 

To support teachers in keeping these important symbols visible and accessible, a handy COSHH poster is available to download below. This visual guide is designed to be a quick reference for both staff and students, helping embed safety into the daily routine of a D&T classroom. The poster will also feature in the upcoming issue of Practice 1.2026, providing an additional resource for classroom inspiration.