Smoking in cars with children present becomes illegal in England on Thursday. The ban will have safety benefits for everyone, according to road safety groups, so here we look at the issue of smoking and driving.

Smoking while driving, or sitting in a car, with anyone under the age of 18 years old will be illegal in England from Thursday. Anyone caught flouting the ban will face a £50 fixed penalty fine, but there will be no points added to the driver's licence.

The driver will also be liable if they let another occupant smoke in the car with minors present, even if the driver himself is not the one smoking.

The law applies to any private vehicle that is enclosed wholly or partly by a roof. It still applies if people have the windows or sunroof open, the air conditioning on or if sitting in the open doorway of the vehicle. It won't apply to a convertible car with the roof completely down.

Second-hand smoke

England joins Wales in introducing the smoking ban and Scotland is set to follow a bid to save children from the proven harmful effects of second-hand smoke.

It is calculated that 430,000 children are exposed to second-hand smoke in cars every week in the UK and the results of passive smoking can be fatal. Children exposed to passive smoking are more at risk of developing asthma, meningitis and even suffering cot death.

Many children do not know the risks they are being exposed to and others feel unable to ask parents to stop smoking. This is why the ban has been introduced, to protect children who would otherwise be put in danger.

Studies have shown harmful chemicals in tobacco smoke remain in the air in a car up to two and half hours, even when the windows have been opened. This stale air contains up to 4,000 chemicals and some of them are known to cause cancer.

For and against

Pro-smoking groups argue the ban is unnecessary because it will be very difficult to enforce.

Simon Clark, of smoking group Forest, said: 'Most smokers know it is inconsiderate to smoke with children in the car and don't do it. They do not need to be told by government or the police. To enforce this law, the government will need an army of snoopers to tell the police of any incident.'

However, road safety groups argue the smoking ban will not only improve children's health when travelling by car but also have benefits for driver safety.

One road safety expert said: 'Lighting a cigarette while driving has been shown to be more distracting than talking on a mobile phone. Holding a lit cigarette when driving is also a distraction that requires to smoker to take his or her hands from the steering wheel at frequent intervals.

'Add to that the danger of hot ash and embers flying around inside the vehicle or the tip of the cigarette burning the driver, it is abundantly clear that smoking and driving do not mix in exactly the same way as drinking and driving do not belong together.'

Safety advice

The advice from road safety groups is, if a car's occupant must smoke, they should pull over where it's safe to do so and have a break from driving while they smoke.

Even so, health experts warn that smoking reduces the level of oxygen in the blood and can reduce driver concentration. Anyone considering driving after smoking should leave at least 10 minutes for their oxygen levels to increase before getting behind the wheel again. It takes 12 hours for oxygen and carbon monoxide levels to return to completely normal after smoking.

David Williams, chief executive of road safety and breakdown cover specialist GEM Motoring Assist, said: 'We welcome the ban, which we believe offers an important step in protecting the health of children. Smoking in cars is particularly bad for children, who cannot escape the poisonous fumes that have been linked to so many health issues and infections.

'We hope the arrival of this new law will give smokers a new incentive to improve their own health as well as that of young people who may travel with them.

'We see this as a great opportunity for all drivers to implement wider safety checks and ensure the risks their children face on road journeys are as low as possible.

'So, as well as ensuring all children now travel in a smoke-free car, we encourage parents and carers to ensure that seat belts are always used – by every occupant on every journey – and that any child safety restraints in use are in good working condition and comply with the law.'