Electric fences are unlikely to harm people, pets or bears because the current or amperage is very low and is not likely to cause injury. However the voltage is very high, for this reason energizers send power through the fence wires in pulses, about once every second. Because the current isn't continuous, the animal or human that comes in contact with the wire has a chance to break free of the fence-feeling only a quick nasty jolt.
The Alaska Department of Fish and Game strongly recommends that you do the following to make your fence as safe as possible.
To be certain you are purchasing a charger that will not harm people, bears, or pets look for a UL-approved label that meets federal safety standards.
Avoid "weed burner" chargers. They have longer electrical pulses than the low impedance models, being designed to burn off vegetation that comes in contact with the fence. These units present a fire danger.
Place appropriate warning signs on the fence.
Use highly visible polytape if you expect visitors to your fence site.
Caution children about touching the fence, using the gate, and operation of the energizer.
Do not set fences up in streams, lakes, or standing water. Water conducts electricity. Animals or humans that stand in water and touch the fence could receive multiple shocks that may cause injury.
Consider using electro plastic wire mesh when possible, or when you think there is a possibility young children may play in the vicinity of the fence. Wire mesh is highly visible and it discourages children and small animals from entering between strands of wire.