Efficacy of air purifiers put to test
'Do not solely rely on air purifiers,' the Consumer Council cautioned yesterday.
The watchdog said that while the machines might help clean the air, they might not completely rid an area of bacteria, viruses, dust mites, allergens and mould. 'Medical opinions have observed that as these devices are designed for domestic use, they may not be able to alleviate all of these impurities,' the council said.
By dusting regularly, keeping the home well ventilated and not smoking indoors, consumers - whether they own an air purifier or not - could help to freshen the air, it said.
Air purifiers might even be associated with a couple of health hazards, the council stated. Some products, which use an ultraviolet lamp, could pose a radiation risk if not switched off before maintenance.
And purifiers that use negative-ion systems might produce harmful ozone emissions - although all systems tested by the council were below ozone-concentration limits, it said.
The council tested 10 units. They were judged on their capacity to deliver clean air, their safety and noise level.
The council found that larger, more expensive units cleaned air the fastest; three machines had plastic parts that could pose a fire hazard; and only four of the 10 brands tested provided information about air-delivery rates.
None received the best rating of five stars, but three - the Sharp KC-C150A, the Panasonic F-PXA28X, and Whirlpool AP33 - scored 4.5.
'Consumers are also reminded of the importance of maintenance of the filter, which needs to be cleaned or changed regularly,' the council said.