A test on single-hob induction cookers revealed that there is room for improvement on the safety designs of 6 tested models.
The Consumer Council, in conjunction with the Electrical and Mechanical Services Department, conducted a test on 15 models of induction cookers within the price range of HK$150 to HK$2,180.
Taking reference of the international standard (IEC 60335-2-9 and 60335-2-6), the Council carried out tests on the cookers' protection against accidental contact to live parts, insulation, temperature rise, construction, marking and instructions.
4 models passed all safety tests. As for the rest of 11 samples, some were found that:
The partial internal printed circuit board and induction coil of 1 sample can be touched by user through a small hole at the bottom. Its protection against electric shock was not up to standard. The Electrical and Mechanical Services Department followed up the case and the agent had announced voluntary replacement in newspaper.
The insulation distances for the fuse-links of two models failed to comply with standard requirements of minor in nature. If the fuse becomes short-circuited, potential risks may arise during abnormal operation.
The design of a touch-sensing induction cooker model needed to be improved since the relevant standard requires 2 independent buttons to be provided for turning on the heater. 2-button design would reduce chances of switching on the cooker accidentally by a single touch.
Coils of induction cookers are usually painted with varnish paints. The volatile organic compounds (VOC) in the paint may vaporize during heating which generates unpleasant smell. Moreover, the plastic cover or plastic materials of the cookers may also cause odors when heating.
The Council examined the concentration level of the total volatile organic compounds (TVOC) of the samples. Among them, 6 models were found emitting concentration levels close to the background level before the cookers started to heat up, while 2 models had recorded relatively higher levels.
The actual input power of 11 samples when measured at local voltage of 220V were found lower than the claimed input power, in which measurement of 2 models deviated from the claimed values by over 20%.
On marking and instructions, 11 samples did not provide detailed instructions, warnings or suggestions. Some are in lack of warnings to user for not connecting the cooker with external remote control or timer, or putting metal objects or lids on the cooker surface. Consumers may not be aware of the potential risks while using the cooker.
The March issue of CHOICE magazine offers tips for consumers on the safe use of induction cookers:
Keep the cooker surface clean. Do not put objects such as cans, knives or forks on the cooker.
Use appropriate stainless steel utensils. Do not switch on the electricity supply until the cooker is ready for use.
Do not share the same socket with other electrical appliances which need high input power.
Check the cooker surface to see if it is cracked or damaged before use.
Do not disconnect the cooker from power sources immediately after use since some cookers are equipped with internal fan motors for cooling down.
There are infrared hotplates available in the market, which look and work similar as induction cookers. However, red light is emitted during heating and the cooking surface heats up. Since they look alike in the shop, consumers are advised to compare and distinguish these 2 types of appliances.
The Consumer Council reserves all its right (including copyright) in respect of CHOICE magazine and Online CHOICE ( https://echoice.consumer.org.hk/ ).