From 0 to 30,000 Hertz is classed as low frequency and 30,000 to 400 million is classed as high frequency and includes radio waves and microwaves.

The second thing to consider is how much electricity is actually being sent. This is measured in volts per meter. The higher the number of volts the more power that is sent either down the wire in the case of low frequency and through the air in the case of high frequency. In the case of the low frequency supply a measurement of 20V/M or below is considered safe.
The third thing to consider is that low frequency electricity going through wires produces a magnetic field around them. Magnetic fields are measured in microtesia. The magnetic fields ideally should be below 0.20 microtesia. Magentic fields drop very rapidly so although you cannot protect yourself from magnetic fields  moving back a short distance will result in a significant drop in the strength of the field.
If you are concerned with the possible health risks relating to electromagnetic radiation or believe that you might be electrically sensitive we suggest three strategies for treatment: Detection, Avoidance and Protection.
To learn more about Electro Sensitivity please click here