Per ESD SP9.2 APPENDIX B - Foot Grounder Usage Guidance “Compliance verification should be performed prior to each use (daily, shift change, etc.). The accumulation of insulative materials may increase the foot grounder system resistance. If foot grounders are worn outside the ESD protected area testing for functionality before reentry to the ESD protected area should be considered.”Per ANSI/ESD S20.20 Paragraph 6.2.2.2 Personnel Grounding Guidance, “ESD protective flooring, used with approved footwear, may be used as an alternative to the wrist strap system for standing operations.”ESD Handbook TR 20.20 paragraph 5.2.3 “If the contact area between the bottom of the foot and the floor is not continuous, charge generation may occur especially when a person is walking. Heel straps must be worn on both feet to minimize the amount of time that the body of the person is isolated from ground while walking.”Suitable for ESD footwear component in Flooring - Footwear System personnel grounding method (<3.5 x 107 ohms per ESD STM 97.1).Suitable for ESD footwear component in flooring - Footwear System personnel grounding method (<100 volts per ESD STM 97.2).