As water is conductive, humidity promotes the flow of electricity. By pulling moisture from the air, some ESD floors may appear to perform better when the humidity is over 40 percent. ... Dry air can will do the opposite. All ESD floors should be conditioned and tested at least as low as 12 percent relative humidity.

How does humidity affect electrostatic discharge?

What Role Does Relative Humidity Play? Drier conditions tend to result in a higher risk of static electricity buildup, which can lead to electrostatic discharges. This is due to the fact that the air moisture content is a natural conductor, earthing any potential static charge.

What is the relationship between ESD and humidity?

Humid air helps to dissipate electrostatic charges by keeping surfaces moist, therefore increasing surface conductivity. Substantial electrostatic voltage levels can accumulate with a decrease in relative humidity, see Table 1 above.