Relative humidity and electrostatic electricity
When friction occurs between two surfaces, there will be an electrical load from the surface atoms stored on both surfaces, creating a potential difference. Most of the time, when both surfaces are connected to ground, these electrical loads discharge quickly, however, if the electrical resistance of the materials is high, sometimes this load will be released, or discharged, on another surface of lower electrical resistance. This discharge is known as an electrostatic energy discharge.
It is of particular importance to avoid these discharges in environments such as operating theatres, where medical personnel work with metallic, electrical instruments on a patient’s body.