Mains-powered appliances produce elevated magnetic fields whenever they draw current. Such fields generally fall as the inverse cube of distance, and thus are significant only within a metre or two of the appliance. Although the peak field can be high - certain electric razors produce over 1000 microteslas (µT) at their surface - people do not usually spend much time close to appliances, so the appliance contribution to time-average exposure is limited. In typical homes, people probably receive about a third of their exposure from appliances and the remainder from net currents in the distribution system.
Typical magnetic field levels from some common mains appliances in the home
Magnetic Field(microteslas, µT)
Close to Appliance
1 Metre Away
Which appliances produce the highest fields?
The highest fields come from some of the smallest appliances, such as the transformer for the front door bell. This is because motors or transformers designed for lightweight appliances often have a minimum of iron in their magnetic circuit, allowing more of the magnetic field to escape.
For example, close to the surface, fields can be 2000 µT for electric razors and hair dryers, 800 µT for vacuum cleaners, and 50 µT for TVs and washing machines.
This means that it is not true that bigger or more powerful appliances produce higher fields. You can see this from the following graph which shows that for 50 appliances, the field is pretty well unrelated to the current they draw: