An ESD Protected Area (EPA) is an enclosed space within which all surfaces, objects, ESDS, and users are kept at the same electrical potential. Relative movements and physical separation of materials or flow of particle-charged solids, liquids, or gases can generate an electrostatic charge. Some examples of ESD damage are:

1. A charged object or person comes into contact with an ESDS item.
2. A charged ESDS device makes contact with another conductive object at a different potential (including a ground).
3. While exposed to an electrostatic field, an ESDS item becomes grounded.

This is why handling and transporting ESDS items inside and outside an EPA will require the use of static protective enclosures made of materials that vary depending on the situation and the destination of the items. Inside an EPA, minor discharge materials, as well as static dissipative materials, can provide adequate protection. Outside of an EPA, the use of low static charge and discharge shielding materials is recommended. These materials are not discussed in this document, but it is important to recognize their different applications. For more clarification on these materials, you can consult the ANSI/ESD S541.