As mentioned earlier, static is all around us. The perception level varies, but the static charge is typically 2000-3000 volts before we can feel it. Remembering that the sensitivity of some parts is under 100 volts, it's easy to see that we might never know that an ESD event has occurred. The innocent-looking styrofoam coffee cup can be a tremendous source of static. Many insulative materials will develop a charge by rubbing them or separating them from another material.
People are often a major factor in generation of static charges.
Studies have shown that personnel in a manufacturing environment frequently develop 5000 volts or more just by walking across the floor. The simple act of lifting both feet off the floor can raise the measured voltage on a person as much as 500-1000 volts. An effective static control program doesn't have to be expensive or complex. The main concept is to minimize generation of static and to drain it away when it does occur, thereby lessening the chance for an ESD event to happen. By implementing a static control program now, you will be prepared for the more sensitive products that will be coming.