Vehicle exhaust emissions




Exhaust emission standards were introduced in 1992 and since then all new vehicles have to be produced with catalytic converters. The catalytic converter takes the by products produced by the combustion process and filters out most of the harmful emissions of hydrocarbons, carbon monoxide and nitrogen oxides before they are emitted from the exhaust pipe. It works by converting these gases into water vapour and less harmful gases.

Emission standards have continued to be made more stringent over the years and today's modern cars produce far lower levels of harmful emissions than they ever have before.

The by-products of an internal combustion engine

In order to reduce emissions, modern car engines control the amount of fuel they burn. They try to keep the air-to-fuel ratio close to the 'stoichiometric point', which is the ideal ratio of air to fuel. In theory, at this point all of the fuel will be burned using all of the oxygen in the air. Unfortunately both the internal combustion engine and it's fuel are far from perfect, and there will always be by-products that will have to be controlled and reduced in some way.


Emission Toxicity and effects
Nitrogen (N2) Non-toxic
Oxygen (O2) Non-toxic
Water (H2O) Non-toxic
Carbon Dioxide (CO2) This is a non-toxic gas, but it is one the major 'greenhouse' gases believed to be causing climate change.
Carbon Monoxide (CO) Toxic. It is a by-product of incomplete fuel combustion. CO reduces the ability of blood to carry oxygen and can cause headaches, breathing problems and in high concentrations, can be fatal.
Oxides of Nitrogen (NOx) Produced in the combustion process, NOx is oxidised in the atmosphere and contribute to acid rain. They can also react with hydrocarbons to produce photochemical oxidants, which can harm plants and animals.
Sulphur Dioxide (SO2) Sulphur comes from crude oil. It forms acids on combustion and contributes to acid rain and engine corrosion. It can also contribute to the formation of ozone and particulate matter.
Hydrocarbons (HC) Hydrocarbons are unburnt fuel and can also through evaporation from the fuel. They react with NOx in sunlight to produce photochemical oxidants which can irritate the eyes and throat.
Benzene (C6H6) Benzene is emitted from vehicle exhausts as unburnt fuel and also through evaporation via the fuel system. Benzene is both toxic and carcinogenic, and long-term exposure has been linked with leukaemia.
Particulates (PM) Particulate matter is partly burned fuel produced mainly from diesel engines. Particulates can get deep into the lungs and cause respiratory conditions.


If you have been involved in a car accident that was not your fault, we can help you get a replacement vehicle, car repairs, legal assistance and injury compensation. Please give us a call on 02392 484 244 , and one of our experienced claims advisors will be happy to assist you.


No need to claim on your insurance

Anyone who has been involved in a road accident has the right to choose who repairs their vehicle. If you were responsible for the accident you were involved in, the company that insures your vehicle would normally deal with your accident claim.

However if you were not at-fault for the accident, you can choose to either claim on your own insurance policy or make a claim independently of your insurer. To find out more call 02392 484 244 and we will be happy to help.

We and our partners help thousands of people make independent accident claims. Our service enables motorists to get the help and assistance they need to resolve their accident related issues, with the costs being recovered directly from the at-fault driver on your behalf.

No excess to pay

Unfortunately even if an accident was not your fault, your insurer will almost certainly require you to pay your excess before any repair is started on your car.

This money should of course be recovered by an insurer at a later date, but with our service - you do not have to pay it at all.

By using our independent claims service, you are not making a claim on your insurance policy and so you will have no excess to pay.

Receive a comparable replacement hire vehicle

Not all insurance policies will include a replacement hire-car for you to use if yours is damaged and unroadworthy. In fact it is typically an 'optional extra' on your policy.

Other policies may offer a 'courtesy car' but this is often just a 'basic' saloon or hatchback which may not be suitable for your needs.

Car Call and its partners will provide a comparable replacement vehicle as part of our service. This means we will endeavour to supply a hire-vehicle that similar to your own in terms of its type, make and engine size.

So whether you drive a small hatchback or a prestige sports car, we will look to provide a similar hire-vehicle that suits your needs.

Manufacturer approved vehicle repairs

If you have been involved in a car accident, the last thing you want to have to worry about is the quality of the repairs to your car. We have a UK wide network of partner approved Accident Repair Centres available to all of our customers.

Many of our accident repair centres are have manufacturer approvals for specific brands, so if you require a manufacturer approved repair centre, simply tell your personal claim handler and they will ensure your vehicle goes to an approved repairer.

Want you vehicle repaired by a specific garage? No problem, we can alternatively use a repairer that you specify.

Legal Assistance

Our partner solicitors provide legal assistance as part of our service. They specialise in motor claims related issues, so you can be assured of the best possible advice and assistance.

They issues they can assist you with include:

  • Recovery of the cost of the replacement hire-vehicle
  • Recovery of the cost of uplifting your damaged vehicle
  • Recovery of all repair costs
  • Recovery of the cost of damaged of personal items
  • Seeking financial compensation for an injury