Guide To COSHH Symbols: What They Are & What They Mean

There are some substances that can cause irritation, injury or death if mismanaged, making their identification and the instruction of safe/prohibited actions crucial to maintaining safety. The Control Of Substances Hazardous To Health regulations (COSHH) provides a framework for safely handling and working with dangerous substances. It includes a collection of unique symbols used to differentiate the various types of substances. Here, we explain all about the nine COSHH symbols so that you can better identify the substances around you and your business.

Corrosive symbol

A corrosive symbol indicates a chemical that could corrode tissue or other materials it comes into contact with. In many cases, contact to the skin or eyes can result in serious (and possibly permanent) injury. The corrosive symbol can be identified by its unique design; two test tubes pouring substances onto a hand and a black object. Corrosive substances are more common than you might think, making the need for adequate signage crucial to complying with the COSHH and protecting the wellbeing of your employees. For example, bleach and drain cleaner both include corrosive chemicals and will include a small corrosive hazard sign on their labels. Alternatively, your business may be involved in the distribution or operation of highly corrosive acids, meaning you must ensure safety measures are in place to ensure they’re managed correctly and safely, including the use of corrosive symbols. For a simple-to-use reference point for the COSHH requirements of your industry, discover the Health and Safety Executive’s (HSE) COSHH Index. 

Toxic symbol

The toxic symbol indicates a particularly dangerous substance which could cause severe injury or death if inhaled, swallowed or touched with bare skin. As a result, it is indicated by the grave image of a black skull and crossbones, signifying the potential for death. From hairdressers to scientific research centres, many businesses handle toxic substances and must ensure they are handled correctly and safely. In fact, the HSE recommends you seek alternatives for all toxic substances where possible. Examples of potentially toxic substances you might find in your business include bisphenols (the main component in plastic manufacturing), fuels and cleaning products, and much more. To learn more about identifying the risks of hazardous substances in your business, refer to the HSE’s guide to COSHH risk assessments.

Warning symbol 

A warning symbol, also known as a health hazard symbol, refers to substances that may cause irritation or damage to health. They are less severe than other inclusions to the COSHH but are just as important to understand so that your business complies with regulations and protects the wellbeing of its workers and visitors. A warning symbol uses a simple black exclamation mark to draw attention to something of importance or concern, and may be found on cleaning chemicals, gases and other types of materials found in manufacturing, construction and more. Warning signs are very common and can even be combined with other COSHH symbols to provide a clearer message in the face of potential harm, such as the Warning Caustic Sign.

Health hazard symbol 

The health hazard symbol, also known as a serious health hazard symbol, is used to depict a substance that can have serious and/or long-term effects on a person’s health. This includes substances that could be fatal if ingested as well as carcinogens, which are more frequently referenced with this symbol. You can identify a serious health hazard symbol by its unique design; a silhouette of a torso with white marks across the chest. In addition, a biohazard symbol may be used where there is waste that could contain potentially infectious substances (such as blood and other pathogens), while a radioactive symbol could be used to indicate the presence of potentially harmful radiation. Unfortunately, there are chemicals we use in everyday and working life that contain known carcinogens, and extreme care must be taken when handling such substances. For example, if you run a construction or renovation company which frequently inspects outdated properties, damp, lead paint and asbestos may be present, all of which are known to cause long-term health problems, and even affect fertility in women.

Hazardous to the environment

A hazardous to the environment symbol is used to signal a substance that may cause harm to the environment. This includes substances with immediate or long-term effects, such as pesticides and petrol. The symbol features an illustration of a landscape with a dead tree and fish, simply showing an unhealthy ecosystem. Taking every reasonable measure to protect the environment and avoid pollution is pivotal to the compliance of modern business, making this symbol a crucial one to understand. If your business works with substances that bear the hazardous to the environment symbol, you must identify this in your risk assessment and record adequate measures to ensure it is handled, used and disposed of in a safe and environmentally friendly manner.

Flammable symbol

A flammable symbol is used to highlight a chemical or substance that could easily catch fire if exposed to naked flames or extreme heats. The symbol clearly demonstrates this with a black flame. They are often used alongside prohibition warning signs, which inform the public and employees as to actions that must not be taken in order to maintain safety. This includes the Danger Highly Flammable No Smoking No Naked Flames sign. There are many situations where your business may need a flammable symbol. For example, the use or transportation of fuels, spirits, aerosols, propane, butane, and many others. If your business does use or transport flammable substances, it should also be highlighted in your fire risk assessment to ensure every reasonable measure is taken to reduce the likelihood and impact of a potential catastrophe. Not only this, but failing to do so could have serious legal repercussions if a fire or explosion was to take place on your premises or site. 

Explosive symbol

An explosive symbol is used to indicate the presence of an explosive substance, fittingly using the image a black explosion. However, there are many reasons a substance might be likely to explode, including instability and flammability. Naturally, the threat of explosion is extremely serious and care must be taken when using or transporting any substance that bears the explosive symbol. For example, if you’re responsible for the safety procedures of a haulage company, you need to ensure any deliveries of explosive substances are handled in a technically safe way with appropriately trained drivers who are aware of the potential hazards and know which actions to take and not take to maintain their safety and those around them.

Oxidising symbol

An oxidising symbol demonstrates that a substance has the potential to cause an exothermic reaction with other chemicals, which could cause a fire, explosion, or increase the intensity or either. This symbol uses a black circle with a black flame emanating from the top and should not be confused with the previously mentioned flammable symbol, which shows just a black flame. Oxidation symbols are fairly common, with most bleach and cleaning products containing oxidising chemicals. These substances should be handled with care and stored in a safe place (away from potential risks of fire or explosions).

Pressurised gas symbol

Pressurised gas symbols are used to indicate a substance classified as ‘gas under pressure’. It is shown by the silhouette of a gas canister. If a pressurised gas canister is damaged or exposed to heat, it can pose a significant risk of explosion, putting your business and its people in serious danger. This can also be used on gas canisters that are kept in refrigerators as they could cause cryogenic burns and injuries if damaged. If your business works with or transports substances such as these, you will need to ensure the correct symbols are present and that the canisters are handled in a safe and secure manner.

At UK Safety Store, we make safety simple for your business, allowing you to focus on what you do best. Whether it's the various COSHH symbols and how they might impact your business, or more information about hazard safety, we’re constantly providing our clients with up-to-date safety guidance in line with UK regulations. To learn more, visit our dedicated resource hub.

Darren Taylor, managing director of UK Safety Store
With over 30 years' experience in the manufacturing and regulations of safety signs, our managing director Darren prides himself on providing the very best services and insights for all UK Safety Store customers.