Customs and the Consumer Council officials have warned parents about cot mattresses, saying several models could see babies suffocated.
Initial investigations by the Customs and Excise Department revealed that four models were suspected to have failed to comply with safety standards on firmness, durability and dimensions. Labels could also be torn off easily, posing risks of suffocation and pinching to infants.
"Investigations are ongoing and appropriate action will be taken if there is sufficient evidence proving violations of the Toys and Children's Products Safety Ordinance by traders," the department said, without naming the brands.
It did not ask the parents to stop using any model, but advised them to buy mattresses with appropriate firmness.
That came on the same day the council released its test report on eight models of cot mattresses - three spring and five foam - sold for between HK$450 and HK$1,398. Half those tested did not comply with European safety standards.
Three models - 0/3 baby, minimoto and Candide - failed to pass tests on firmness and durability, which could result in suffocation if infants roll over on to their faces while sleeping and end up face down on the mattresses.
The decals on the mattress could loosen after 30 pulls on two models - 0/3 models and Candide, which also posed suffocation risks for babies if the decals covered nose and mouth.
The council also said there is a danger that the baby may trap limbs, fingers, toes and head if the gap between the cot frame and mattress is too wide. In the C-Max model, there was a discrepancy of more than 10 mm between actual dimensions and its claim.
Test results show price is not an indicator of quality.
The council said IKEA's HK$790 spring mattress and HK$450 foam mattress - the cheapest models in the spring and form categories - have the best performance.
Clement Chan Kam-wing, chairman of the council's publicity and community relations committee, said all tested models have poor performance in moisture and air permeability, which could cause discomfort to babies because of heat and dampness.
Council chief executive Gilly Wong Fung-han encouraged parents to try the mattresses to ensure they come with the right firmness.
"It cannot be too hard or too soft. If it is too soft and the baby's face is lying down when sleeping, it can cause a very high risk of suffocation. But if it is too hard, it may cause discomfort to your kid."