Since the adoption of the European standard for portable extinguishers, every new extinguisher sold in the UK has a red body. The agent is identified by a coloured band or panel, usually across the top of the cylinder or around the pressure gauge. That single change is the source of most of the confusion on this subject, because a building may still hold older units whose whole body carries the agent colour, sitting next to new ones that do not.
The bands and what sits behind them
Red signals water. Cream signals foam. Blue signals dry powder. Black signals carbon dioxide. Yellow signals wet chemical. Those five cover almost every portable extinguisher a duty holder will meet in a British building. A sixth, occasionally seen in specialist settings, is the class D powder unit for metal fires, which is normally supplied with a hand applicator rather than a hose and is never part of a general provision.
Why the body is red and the band is not
A red body with a coloured band is a deliberate compromise. It keeps every extinguisher visually identical at a distance, so that a person under stress looks for the same shape in the same place on every floor, while the band does the work of telling a trained user which unit to reach for. The older all-over colours were easier to read at arm's length and harder to see across a room, which is why the standard moved.
Reading a code is not the same as choosing a unit
The code answers what is in the cylinder. It does not answer whether the cylinder belongs where it is standing. That question is settled by the fire risk assessment, which identifies the fuels present, and then by the provision rules: the right agent, in the right size, at a point a person can reach without walking towards the fire. A correctly coded extinguisher in the wrong place is still a defect.
What an inspector actually checks
An enforcing officer is not testing whether a person can recite the colours. They are looking for extinguishers that match the risks named in the assessment, a service record that is current, signage that identifies each point, and staff who know which unit they have been told to use. The colour code is the mechanism that makes the last of those teachable rather than memorised.
Questions people ask about fire extinguisher colour codes uk
Are the old all-over colours still legal?
An extinguisher in the older colour scheme is not unlawful simply for being old. It has to be in good order and properly maintained. In a building that holds both schemes the practical problem is training, because two visual languages are in use at once, and that is usually the argument for standardising as units are replaced.
Does the band have to be a fixed size?
The standard sets the proportion of the body the agent colour may occupy, which is why it appears as a band or a panel rather than a large field. What matters for a duty holder is that it is visible from the front without handling the extinguisher.
Where should the code be recorded?
In the fire risk assessment and in the maintenance record. Both need to say what agent is at each point, because the argument that a building was correctly equipped is made from documents long after the extinguishers themselves have been swapped.