Conductive floors or grounded conductive floor mats are mandatory in any EPA where personnel handling ESDS items are not wearing wrist straps. Under these circumstances, personnel shall use leg straps, heel straps, or conductive shoes.
ESDP flooring or floor mats shall be used in all Class 1 facilities.
The proper cleaning and maintenance of a conductive floor is of extreme importance since the use of normal floor wax on conductive floors or floor mats can defeat their effectiveness. Personnel cleaning these items shall use the manufacturer approved cleaning agents and cleaning recommendations as minimum requirements. With guidance from the ET&V Officer, the Facility ESD Monitor will determine the cleaning regimen for the flooring and mats if the manufacturer’s recommendations are not acceptable.
Conductive/dissipative floors or grounded conductive/dissipative floor mats shall have a maximum resistance to ground of 1×109 ohms and a minimum resistance of 1×105 ohms. The test methodology for flooring is found in ESD S7.1 “ESD Association Standard Test Method for the Protection of ESDS Items – Resistive Characteristics of Materials – Floor Materials”.
Standard carpeting shall not be used in an EPA. Even the use of ESDP carpet woven with conductive fibers, which have previously been approved for use at JSC, can still be very problematic. If the conductive fibers are not dense enough, the resistance to ground will increase as the carpet wears. The selection of carpet in an EPA environment shall require pre-installation approval of the ET&V Officer.