Pool cars need ozone treatment because they change drivers constantly, and the odour each driver leaves settles into seat fabric, headlining and ventilation ducts that a wipe-down never reaches. Ozone is a gas, so it treats the whole sealed cabin at once and breaks odour down at source rather than masking it — which is why it suits shared cars in particular.
How does ozone treatment work in a car cabin?
Ozone (O₃) is a reactive form of oxygen that oxidises odour-causing organic compounds. A generator raises the ozone level inside the sealed cabin, and because it is a gas it spreads through the whole interior volume — seat fabric, headlining, carpet and the ventilation ducts — rather than only the surfaces a cloth or spray touches. Afterwards it breaks down back into ordinary oxygen and leaves no residue.
Ozone is also harmful to breathe at treatment levels. The car must be sealed and unoccupied during treatment and properly aired before anyone gets back in, which is why it should be done by a trained operator rather than left to drivers.
Why do pool cars carry more hygiene and odour problems?
A company car assigned to one driver is largely that driver’s own space. A pool car may have several drivers in a day, and each leaves traces — food and drink, damp clothing, smoke on clothes, pet hair — in the fabric and air system. None of it looks like much, but it builds up in places no one cleans, and the car starts to smell.
The practical consequences are everyday rather than dramatic:
- Drivers avoid the car. A pool car with a persistent smell gets passed over, which shrinks the usable pool and pushes mileage onto the others.
- Allergy and comfort. Musty ventilation is unpleasant for anyone and worse for drivers with asthma or allergies.
- The next driver’s impression. Every handover is a fresh first impression of how the business looks after its cars.
Where does cabin hygiene sit in an employer’s duty of care?
It sits within the general duties. The Health and Safety at Work etc. Act 1974 requires employers to ensure, so far as reasonably practicable, the health, safety and welfare of employees, and the Management of Health and Safety at Work Regulations 1999 require them to assess the risks of work activities. Neither sets a cleaning schedule for cars, but a risk assessment for shared cars that ignores the state of the cabin is incomplete. Our piece on whether HSE workplace cleanliness rules apply to company cars sets out where the duty comes from, and pool car hygiene and duty of care covers the shared-car case in more depth.
How does ozone compare with other cabin treatments?
Its advantage is reach: it treats the whole sealed cabin rather than the surfaces someone can get to.
| Method | What it reaches | Effect on embedded odour |
|---|---|---|
| Surface wipes and sprays | Touchpoints only | Masks at best |
| Steam cleaning | Fabrics within reach of the nozzle | Partial |
| Fogging | Surfaces the droplets settle on | Partial |
| Ozone treatment | The whole sealed cabin, including vents | Breaks odour down at source |
Ozone does not replace cleaning. Dirt, spills and crumbs still need a valet; ozone deals with the odour that remains after them.
What does an ozone treatment look like on site?
The car is valeted where it is parked, sealed with windows up and doors closed, and treated with the generator inside. It is then ventilated before it goes back into use. There is no water, nothing applied to the surfaces and nothing to dry, so the car does not need to go anywhere or sit in a bay. MMCC’s mobile ozone odour removal is £45 per car, added to a valet; details are on our mobile ozone odour removal page.
How often should pool cars be treated?
Match the frequency to how many people use the car. A pool car with several drivers a day will need treatment more often than one shared between two named drivers, and any car that has carried a smoker, a wet dog or a spilled meal needs it straight away. A regular valet with a recorded 20-point Vehicle Health Check gives the fleet manager a dated note of interior condition at each visit, which shows when a car needs more than a clean.
Does odour matter at lease return?
Yes. Leasing companies assess interior condition at return against the BVRLA fair wear and tear guide, and odour that a standard valet cannot remove — smoke especially — is the kind of interior condition that attracts a charge. Treating odour at source before return, rather than masking it with air freshener, is the straightforward answer. More on the return itself in reducing end-of-lease charges.
Our rounds cover mobile car valeting in Esher and car valeting in Kingston upon Thames, and fleet programmes, including ozone, are set out on our Corporate fleet services page.
Fleet managers can plan ozone treatment and valeting across their pool cars through a Fleet Readiness Audit.