Badly designed child car seats increase the risk of serious head and chest injury or even death in a crash, with four out of 17 test samples providing inadequate protection, the Consumer Council said yesterday. Front-impact tests showed the four products that failed to meet safety standards increased the risk of shocks to the head and chest. Six other seats that claimed to be suitable for weights up to 13kg were found to be too small for babies weighing 9kg. The report also warned children could die or suffer serious injury if a rear-facing seat was mounted on a front passenger seat fitted with an airbag. Some of the rear-facing seats failed to provide this airbag warning. But the council's publicity and community relations committee chairman, Dr Lo Chi-kin, said despite the problems, the use of child-restraint systems offered a 'far better degree of protection than using a loose adult seat belt or no restraining device at all'. 'If parents place these seats in the back, it will reduce the risk to the child. 'It is a last resort to have the car seat in the front. We hope the car seat manufacturers can improve the level of protection as there is room for improvement.' Dr Lo said there was no international standard on measuring side impact and called for a review of guidelines. He added parents should note the size of their children before buying seats. 'Some manufacturers indicate the age range suitable for their products but the most important indicator is actually the size and weight of the child. So a younger child who is heavier may not need the restraint.' Dr Lo called on suppliers to provide adequate warnings and manuals in English and Cantonese as child car seats were often installed incorrectly, making them unsafe. According to the crash tests, the worst-performing restraints were Century Smart Fit, Evenflow Discovery, Safety Baby Challenger/First and Mothercare Daytona. The dummies in the child seats moved forward and hit the front seat and other parts of the car. Shock absorption was insufficient and vibration increased the risk of head and chest injury. The restraints recommended for use were Britax Rock-a-tot Deluxe, Cam S146 Ciao Plus and Britax Freeway. The 17 test samples, priced from $500 to $2,500, included eight rear-facing seats, four forward-facing seats and five suitable for both rear and forward-mounting.