Parents have been warned not to let children put toys in their mouths after many were found to contain a toxic agent that could cause liver or kidney damage.
The Consumer Council's warning came after it found phthalates at concentrations up to 300 times the United States and European Union standards in over half the toys it tested.
The substances, used to make hard plastic flexible and more durable, are banned by the US and EU in children's toys at concentrations greater than 0.1 per cent.
Of the 27 toys the council tested, 16 contained phthalates and four had concentrations of 28 to 38 per cent.
The council's chief executive Gilly Wong Fung-han urged parents to check toy labels carefully before buying them and to wash them thoroughly before letting their children play with them.
"Parents shouldn't let young children play with toys alone and they should make sure they do not put the toys in their mouths," she said.
Tests on animals have linked chronic exposure to phthalates to liver and kidney problems.
Although the toxicity levels are not high enough to pose a direct health threat to adults, young children are at risk because of their tendency to chew or suck on toys.
A Customs and Excise Department spokeswoman said that there were currently no controls and regulations on the use of plasticisers in children's products.
The Legislative Council is considering amending the Toys and Children's Products Safety Ordinance to introduce control over phthalates in toys.
"From a scientific perspective, the danger of phthalates to humans is still up for debate … but it is not too late for Hong Kong to enact stricter regulation," said Professor Michael Hui King-man, chairman of the council's publicity and community relations committee.
The samples tested included bath toys, toys designed for youngsters to ride on and an alphabet puzzle board.
Meanwhile, the council also warned consumers of a series of safety hazards in unbranded Christmas lights, saying some were "probably too good a bargain to be true".
A joint test conducted by the council and the Electrical and Mechanical Services Department on 17 Christmas lights - four unbranded and 13 branded - found all four unbranded samples failed safety compliance regulations for electrical products.
In some samples, only single insulation protection was provided in the wiring - a defect that could lead to overheating, melting, fire or electric shock.