ESD and Static Control Questions Answered

People are a great generator of static electricity, among other things. The ESD gloves, aprons, etc. enable you to work and interface with sensitive components and equipment while protecting them from an ESD event as well as other things like contamination from human skin, street clothes, dirt, dust, etc. It will be mandatory for personnel ground to wear a wrist strap when in seated operations in a manufacturing environment or in the field. For personnel ground in an environment where you are standing or walking about, you do NOT have to wear a wrist strap if you have sufficient ESD footwear in conjunction with an ESD flooring system. The above requirements are per ANSI/ESD S20.20-1999 Table 1.

b. IS IT NECESSARY TO USE THE ESD GARMENTS? IS IT NOT POSSIBLE TO GROUND THE CHARGES DEVELOPED THROUGH A PERSON'S CLOTHINGS THROUGH THE HUMAN BODY WHICH IS GROUNDED THROUGH THROUGH A WRIST STRAP / FOOTWEAR / OR HEEL STRAP WHILE WORKING AT AN EPA?

This depends who’s in charge.  If the ESD manager wants to require ESD personnel clothing and redundancy of ESD compliance for improved ESD control, they are the one to determine that.  More and more I’m seeing the use of ESD smocks outside of the cleanroom environment.  The company and their clients are reaping the benefits of increased quality control and reduced “out of box failures”.  Cloth is proven to be a better conductor of ESD charges than some types of clothing, but not everybody wears cotton.  Some people have dry skin and the ESD garments are a good idea for added protection and a requirement in some environments.

c. AGAIN ;  IS IT NECESSARY TO USE ESD CHAIR  WHEN THE HUMAN BOADY  IS  ALREADY  GROUNDED THROUGH A WRIST STRAP / FOOTWEAR / OR HEEL STRAP WHILE WORKING AT AN EPA ?  

I think it’s a great idea.  I can be sitting at a workstation with an ESD flooring system, have a wrist strap on and when I get out of my chair, not generate more than 50 volts.  I may not generate more than 5 volts.  But what if I take my wrist strap off and jump out of my chair?  I can easily generate 100’s of volts.  Oh, by the way, jumping should not be allowed in an EPA.  If you have great ESD shoes or sole grounders and you keep at least one foot firmly planted on the ground at all times, then maybe your ESD chair is redundant, but still an added piece to the chain in your EPA system.