Most ordinary vehicles in the UK are not required to carry a fire extinguisher. The requirements that do exist come from licensing conditions, from carriage of dangerous goods rules, and from an employer's own risk assessment, and those three reach different vehicles for different reasons.
Where a requirement comes from
Taxi and private hire licensing conditions are set by the licensing authority and very commonly require an extinguisher and a first aid kit. Vehicles carrying dangerous goods are subject to carriage regulations that specify extinguisher provision by vehicle weight. And an employer whose staff drive for work has a general duty to assess and control the risk, which for some fleets produces an extinguisher policy and for others reasonably does not.
Which type
Dry powder is the usual choice for vehicles: it is electrically safe, it covers the fuels and plastics involved, and the visibility and residue objections that rule it out indoors matter much less outdoors. It needs a secure bracket so it is not loose in a collision, and a position somebody can reach from outside the vehicle rather than one that requires climbing into a burning cab.
Construction sites and site accommodation
Construction fire safety is a specific discipline with its own HSE guidance, and provision covers hot works, fuel storage, waste, site cabins and plant. Site offices and welfare units are premises in their own right and need the provision any small office would, which is frequently forgotten because they look temporary. Hot works permits normally require extinguishers at the work position and a fire watch afterwards.
Electric and hybrid vehicles
A lithium battery fire in a vehicle is not something a portable extinguisher will resolve, because the cells sustain their own reaction and reignite. The realistic response is to get everybody away and call the fire service, telling them it is an electric vehicle. An extinguisher in an electric van is still useful for the ordinary fires that start in cabs and loads, which is what it should be understood as covering.
Questions people ask about vehicle fire extinguisher
Does a van legally need a fire extinguisher?
Not generally. Requirements come from licensing conditions, from dangerous goods carriage rules, or from an employer's own risk assessment rather than from a blanket legal duty on all vehicles.
Which extinguisher goes in a vehicle?
Dry powder is the normal choice: electrically safe, broad coverage, and the indoor objections to powder do not apply. Mount it securely and where it can be reached from outside.
Can an extinguisher put out an electric vehicle battery fire?
No. A lithium cell fire sustains itself and reignites. Get people clear and call the fire service, telling them the vehicle is electric.