Hot water bag what kind of safety

Electrode type hand-warming bags have significant safety risks, China clearly stipulates that "electrodes can not be used for liquid heating at the same time", but because of the low cost of such hand-warming products, many electric hot water bags on the market now are electrode type. So how to identify the three and then select a safe electric hot water bag?

Electric heating wire type, heating tube type electric heater in the handbag heater volume than the electrode type is much larger, can touch the mesh structure wire wire structure or U-shaped tubular structure, while the hot water bag brand electrode type electric water heater bag can significantly touch 2 metal material electrode. Therefore, you can rely on this feature to distinguish the three, but the internal structure of the electric water heater bag electric wire or heating tube will also aging, and thus the same electric water heater bag use time should not be too long.