Standard
ANSI/ESD S20.20-2021
Sets the requirements for an ESD control program, and with it the system level thresholds a qualified floor has to support.
What it means for your floor
What it actually governs
S20.20 is a program standard, not a product standard. It tells an organisation that handles ESD sensitive electrical or electronic parts how to run a control program: what has to be qualified, what has to be verified, and how often. Flooring is one item inside that program, which is why the standard sets a system threshold rather than a floor specification.
The two numbers a floor has to support
A person wearing static control footwear standing on the floor has to measure under 1.0 x 10^9 ohms, and generate under 100 volts while walking. Those are the numbers your floor is bought to satisfy, and they are measured with the person in the circuit, never on the floor alone.
Why your floor alone cannot pass or fail it
The measurement is a series circuit: person, footwear, floor. Change the shoes and the number changes. That is why an ESD floor is specified alongside a footwear policy and why a floor that passed under one program can read differently under another.