Static electricity is created when two objects or materials that have been in contact with each other are separated. When in contact, the surface electrical charges of the objects try to balance each other. This happens by the free flow of electrons (negatively charged particles) from one object to the other. When the objects separate, they are left with either an excess or a shortage of electrons. This causes both objects to become electrically charged.
The rubbing of a fabric, even in the course of normal everyday wear, can build up static electrical charges of over 5000 volts. Should the wearer then touch a grounded object the discharge promotes a small electric shock, accompanied by an electric spark. In the presence of flammable vapours or dust, the discharge of the static electricity may be great enough to cause an explosion.
The risks of static electricity to humans are explosion or fire. Static electricity creates sparks in an explosive or flammable atmosphere and can cause 1st, 2nd of 3rd degree skin burns.