Only about 10 per cent of unsafe household heaters recalled by suppliers following Consumer Council findings last June have been returned.
The council had tested 16 models and found that most could short circuit or give an electric shock. Some posed a fire risk.
The five models deemed most dangerous, and which were recalled by suppliers, were: CoCo NSG 3-18 fan heaters, Daiwa PS-8616, Evernal HT-2000, Mitsumaru SH-1000 and Sitolan SY-636.
Other less-hazardous models were either stopped at the supply stage or had their designs improved.
Acting senior electrical and mechanical engineer Chan Yau-man, of the Electrical and Mechanical Services Department, urged consumers to return the heaters.
'Up to a few hundred of these heaters are still in people's hands. We also don't rule out the possibility that retailers are still selling from stock. People with these heaters should return them to suppliers,' he said.