One third of eight to 11-year-olds are being put in danger during car journeys as they are not using a mandatory booster seat, a new report has revealed.
Good Egg Safety, an organisation providing in-car safety advice for families, revealed that out of a sample of 2,351 children aged 0 to 11, only 598 had a booster seat.
Current UK law requires children to use a booster seat until they are 12 years old or 135cm tall, (whichever comes first).
The research found that 34% of children aged eight to 11, were travelling using just an adult seat belt, when a booster seat was legally required.
"If older children do not use a booster and are too small for the seat belt, the belt can cause very serious – or even fatal – injuries," warned Jan James, Good Egg safety chief.
"We are very concerned about the results showing that a third of older children are not using a suitable booster seat," James continued.
"Seat belts are designed for adult use and are not suited to a child’s anatomy.
"A booster lifts a child up high enough that the adult seat belt fits across their hips and chest safely."
The study found issues with children who were travelling in car seats, too.
Of the children aged two to 11 who were in a booster seat, 67 children were in a seat they were too small for.
More than half of the 93 children aged two to three years old were in the wrong seat for their age, weight or height.
Sarah-Jane Martin, spokesperson for Brake, the road safety charity said these figures are "very worrying".
"It’s vital that all parents understand that it’s not just toddlers who need protecting," she said.
"We’re supporting Good Egg Safety with this important awareness raising campaign and ask all parents to ensure that their child has the appropriate safety seat fitted."
Statistics from the Department for Transport show In 2014, there were 2,040 eight to 11-year olds killed or injured in collisions, compared to 1,553 among five to seven-year-olds.
What shop staff should ask parents when buying a car seat, as reported by Good Egg Safety.
Child's weight
Child's height
What vehicle the seat will be used in
If the seat will be used in any other vehicles
If the vehicle has ISOfix
If the seat is fitted to the front of the vehicle - advise on airbag risk
They should also advise on the safety benefits of rear facing child seats and demonstrate the fitment of the car seat.
Honor Byford, chair of Road Safety GB, the charity that supports road safety professionals, said: "We know that every parent’s strongest instinct is to protect their children.
"We urge parents to check out the legal requirements and keep their children on the right booster seat for as long as their child needs that extra protection – which is until they are tall enough for an adult seatbelt to fit their body."
Parents have been advised to invest in a high-back booster seat for extra protection for older children, rather than a booster cushion.
Kat Furlong Good Egg Safety training expert added: "A high-back booster is far more preferable to a booster cushion, to provide children with adequate head, neck and torso protection from side impacts, which booster cushions do not offer.
"We implore parents to buy these instead and ensure they are the right seat for their child and car."
For more information on booster seats, visit www.goodeggcarsafety.com/blog/goodmorningbritain.