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We have a conductive production floor along with many other ESD controls in place (shoes, wrist straps, etc.). I was told we are supposed to only purchase ESD Type 1 shoes. What are the specifications for a Type 1 shoe? If you have any information about the other types of shoes and their specifications I would greatly appreciate it. -Anonymous

The ANSI Z41-1991 Standard classifies Static Dissipative (SD) footwear into 2 categories: 1) SD Type I Footwear. The electrical resistance will not exceed 1x10^8 ohms (100 megohms) which is generally considered acceptable for semiconductor applications.

2) SD Type II Footwear. The electrical resistance will not exceed 1x10^9 ohms (1,000 megohms) which has applications in work environments less demanding than SD Type I. Both SD Type I and SD Type II Footwear shall have a lower limit of resistance of 1x10^6 ohms (1 megohm) to maintain a sufficiently high level of resistance to protect the wearer from electrical hazard.There is a newer standard out, ANSI/ESD-S20.20-1999, that is suggesting that the equivalent electrical resistance from body-footwear-floor-ground be less than 35 megohms [ESD STM 97.1] which implies that the shoes need to be a lot closer to just the megohm level and not 100 or 1,000 megohm level to comply.

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