Comfortable and aesthetically pleasing shoes and clogs provide a safest , efficient conductive path to ground.
According to the IEC 61340-5-1 2017-01 regulation all operators shall be connected to ground when operating in contact with ESDS.
In case of personnel seated at an ESD protective workstation, they shall be connected to ground via a wrist strap system (Rg between 750kΩ -35MΩ) .
Standing operators may be grounded via a flooring / footwear system. When only the flooring / footwear system is used to ground it is necessary to wear ESD footwear on both feet and satisfy these 2 conditions:
Total resistance of the system (person, footwear and flooring) to ground:
Rg < 1,0 x 10^9Ω
Maximum HBV (Human Body Voltage) generation:
HBV < 100V
Rg shall be measured during the product qualification according to IEC 61340-4-5 and HBV shall be checked periodically (note "d" Table 2 of the standard)
For compliance verification the person / footwear system must be checked at a groundable point:
Rgp <1,0 x 10^8Ω