Electrostatic discharge (ESD) is the sudden flow of electricity between two electrically charged objects. The likelihood of static charge buildup is significantly higher in environments with low relative humidity. Dry air acts as an insulator, allowing static charges to accumulate on surfaces, including human bodies. By implementing proper temperature and humidity controls, specifically maintaining a relative humidity level typically between 40% and 60%, the moisture in the air provides a conductive path that helps to safely dissipate these static charges before they can build to a level that could damage sensitive electronic components.

A. Uninterruptible power supply: This device provides backup power during an outage and conditions line voltage; it does not mitigate environmental static electricity.

B. Surge protector: This device protects equipment from voltage spikes originating from the power grid, not from electrostatic discharge.

C. Power distribution units: These are used to distribute power to multiple devices within an equipment rack and lack inherent ESD prevention capabilities.

1. MIT Environmental Health & Safety

"ESD Control Program Guideline

" EHS-0255. Section 5.2

"Humidity Control

" states: "Low humidity promotes the generation of static electricity... Maintaining the relative humidity between 40% and 60% will minimize charge generation and accumulation."

2. NASA Technical Standard

NASA-STD-8739.7A

"Electrostatic Discharge Control (Excluding Electrically Initiated Explosive Devices)." Section 5.1

"General

" specifies: "The preferred range for relative humidity for ESD control is 30 to 70 percent... When the relative humidity cannot be maintained in the preferred range

additional precautions shall be taken..."

3. University of California

Berkeley

Electrical Engineering and Computer Sciences Department

"EECS 151/251A Lab 1: FPGA Toolflow." The "ESD Prevention" section of the lab manual advises: "Static electricity is a much bigger problem in dry environments. We try to keep the humidity in the lab at 50% to help reduce the risk of ESD."