The wider band
Static dissipative: 1.0 x 106 to 1.0 x 109 ohms
This is the band most electronics work runs on[5]. It still drains a charge, just more gradually than the conductive grade, and that gentler bleed is the point when the thing you are protecting is a component rather than an atmosphere.
Why the band is wider
A dissipative floor sits between an insulator and a conductor on purpose. It gives a charge a route away without offering a fast one, so a person picking up a charged item does not hand it a sudden path. The ESD Association describes the trade directly: dissipative is the general answer, and conductive is for cases where full elimination of discharge risk is the requirement[5].
The system is what gets qualified
S20.20 does not test the floor alone. It tests a person, their footwear and the floor in series, and the ceiling is under 1.0 x 109 ohms[1]. Your footwear choice is part of the answer, which is why a floor that passes under one shoe can fail under another.
There is a second, older path
The pre-2014 S20.20 approach used a 3.5 x 107 ohm ceiling for the person, footwear and floor in series, and it is still carried in EN and IEC 61340-5-1[16]. If your program document quotes that number, it is not out of date, it is on the other path.
The international equivalent
IEC 61340-5-1 is the international counterpart to ANSI/ESD S20.20, and Edition 3.0 landed in 2024[6]. The change that matters most to a flooring buyer: a facility can now qualify its ESD control items, flooring included, at the lowest relative humidity that facility actually experiences across the year, rather than against a fixed arbitrary benchmark[18].
Questions
Do you install static dissipative floors?
The conductive system is what New Era installs. A dissipative system is available if your specification calls for it. Send the spec over and we will tell you plainly whether it is a fit, before anybody quotes a number. Send it here.
Is dissipative worse than conductive?
No, and the ESD Association says so directly[5]. They are different bands for different risks. Dissipative is the usual answer for handling ESD sensitive parts. Conductive is for where the discharge itself is an ignition source.
Our spec quotes 3.5 x 10⁷ ohms. Is that wrong?
Not wrong, just the other path. That is the legacy system resistance ceiling for a person, footwear and floor in series, from the pre-2014 S20.20 approach, and it is still carried in EN and IEC 61340-5-1[16].
Does humidity change whether we pass?
It can, which is why IEC 61340-5-1:2024 lets a facility qualify at its own lowest annual relative humidity rather than a fixed benchmark[18]. A floor qualified in a humid month can read differently in a dry one.
Sources
- ANSI/ESD S20.20-2021, the ESD control program standard for electronics handling
ESD control program requirements (administrative and technical) for any organization that handles ESD-sensitive electrical or electronic parts.
www.esda.org - ESD Association: conductive or dissipative static control flooring, how to choose
Cited here for the static-dissipative flooring resistance band per the ESD Association.
www.esda.org - IEC 61340-5-1:2024 Edition 3, the international ESD control program standard
International equivalent of ANSI/ESD S20.20: general requirements for an ESD control program protecting electronic devices.
webstore.iec.ch - How ESD flooring is qualified, and the legacy 3.5 x 107 ohm series path
Cited here for the alternate/legacy system resistance qualification path for person plus footwear plus floor in series.
incompliancemag.com - Does an ESD control program require humidity control, and the 2024 change
Cited here for the IEC 61340-5-1:2024 lets ESD control items, flooring included, be qualified at the facility's own lowest annual relative humidity rather than an arbitrary fixed.
incompliancemag.com
Every number on this page came from one of those documents. Send us the room and we will tell you which of them your floor has to answer to.