If your business uses cleaning chemicals, solvents, fuels, paints, pesticides or any substance carrying a hazard pictogram, the law expects you to store it safely. A COSHH cabinet is the standard way to do that — but not every metal cupboard qualifies. This guide explains exactly what a compliant COSHH cabinet must do, what the regulations require, and how to choose the right unit for your workplace.
What is a COSHH cabinet?
A COSHH cabinet (also called a hazardous substance cabinet or COSHH cupboard) is a steel storage unit designed to hold substances that are hazardous to health — corrosive, flammable, toxic, irritant or harmful materials identified under the Control of Substances Hazardous to Health (COSHH) Regulations 2002. Its job is to contain leaks and spills, keep incompatible chemicals apart, restrict access, and clearly signal the hazard inside, so that hazardous substances do not put workers, visitors or the building at risk.
COSHH cabinet requirements at a glance
A compliant cabinet should meet five core requirements:
- Lockable — doors must lock so access is limited to trained, authorised staff.
- Rigid, non-corrosive construction — typically heavy-duty powder-coated or galvanised steel that resists impact and the substances stored.
- Integral sump (spill bund) — a welded, leak-proof tray in the base that captures spills and leaks before they spread.
- Clear hazard labelling — exterior signage showing the relevant GHS/CLP pictogram (flammable, corrosive, toxic and so on).
- Suitable location and ventilation — sited away from heat, ignition sources, food and escape routes, with ventilation where volatile vapours are a concern.
What size sump does a COSHH cabinet need?
The sump is the single most important feature. The widely used UK benchmark is that the sump should retain at least 110% of the volume of the largest container stored in the cabinet, or 25% of the total volume of all substances held, whichever figure is greater. This mirrors the bunding rule applied to bulk liquid storage and ensures that if a container fails, nothing escapes onto the floor, into drains or into the wider environment. When you compare cabinets, always check the sump capacity against the biggest container you intend to store.
Do COSHH cabinets need to be locked?
Yes. Restricting access is a fundamental control under COSHH. A lockable door keeps hazardous substances away from untrained staff, visitors and — on many sites — the risk of deliberate misuse or theft. Keys or combination access should be held only by people who have been trained to handle the substances inside. For higher-security needs, dedicated COSHH security cupboards add reinforced locking.
Do COSHH cabinets have to be yellow?
No — colour is a convention, not a legal requirement. The law requires clear hazard signage; the colour of the cabinet is a widely adopted visual shorthand rather than a statutory rule. That said, the colour-coding is well understood across UK industry and worth following for quick identification:
- Yellow — flammable liquids such as solvents and fuels.
- Red — general chemical and health hazards.
- White — corrosive substances, including acids and alkalis.
- Green — pesticides and environmental hazards.
Whatever the colour, the cabinet must carry the correct hazard pictograms for what is actually stored inside.
Segregating incompatible substances
One cabinet does not suit every substance. Incompatible chemicals — concentrated acids and flammable solvents being the classic example — must be stored separately to prevent dangerous reactions, heat or the release of toxic gas. In practice this means dedicated cabinets: a flammables cabinet for solvents and fuels, an acid/corrosive cabinet for aggressive liquids, and a separate unit for pesticides or agrochemicals. Always read the safety data sheet (SDS) for each substance and follow its storage and segregation advice.
Where should a COSHH cabinet be located?
Position matters as much as the cabinet itself. Site units in a well-ventilated area, away from direct heat and ignition sources, clear of high-traffic routes, and never blocking or adjacent to fire-escape routes. Keep them away from food preparation and welfare areas. Where the substances give off volatile vapours, choose a cabinet suitable for connection to local exhaust ventilation (LEV). Outdoor or yard storage — common for gas cylinders — needs a ventilated, weather-resistant solution rather than a sealed indoor cabinet.
Capacity limits for flammables
Fire-safety and building rules often restrict how much highly flammable liquid can be kept in a single working area before it must move to a dedicated store — a figure of around 50 litres in one indoor area is commonly cited as a practical trigger. If you hold larger volumes, you will likely need a larger flammables cabinet or a separate, fire-rated store. Your fire risk assessment and DSEAR assessment should set the exact limits for your site.
Which standards apply?
The key references are the COSHH Regulations 2002, the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR), the CLP Regulation for hazard classification and labelling, and BS 5993 construction practice for hazardous-substance cabinets. The Health and Safety Executive provides the authoritative overview on its COSHH pages, including how to carry out a COSHH risk assessment — the starting point for deciding what storage you actually need.
Choosing the right COSHH cabinet
Bring it together in five steps: (1) list your substances and read each SDS; (2) group them into compatible classes and plan a cabinet per class; (3) size each cabinet's sump to the largest container and the total volume; (4) decide floor-standing or wall-mounted, and indoor or outdoor; (5) confirm signage, locking and ventilation suit the substances and the location.
At KC Supply our hazardous storage range covers compliant flammable, acid, pesticide, petroleum and lithium-ion battery cabinets, plus COSHH security cupboards — all sump-bunded, lockable and built to the requirements above. For compressed gases see our gas cylinder storage cages, and for secondary spill protection browse spill containment. Our team are former engineers — send us your substance list and we will point you to the right compliant cabinet.
This guide is general information, not a substitute for your own COSHH and DSEAR risk assessments. Always follow the safety data sheet for each substance and current HSE guidance.