Questions And Answers

We cannot give safety advice and do not know the safety codes in China.

In the United States, an AC electrical outlet includes a grounding conductor which is the preferred ground.

Here is some grounding information from the ESD Association:

"The single most important concept in the field of static control is grounding. Attaching all electrically conductive and dissipative items in the workplace to ground allows built-up electrostatic charges to equalize with ground potential.  A grounded conductor cannot hold a static charge." [Grounding ANSI/ESD S6.1 Foreword]

Per ANSI/ESD S20.20 section 6.2.1.2 Grounding / Bonding Systems Guidance, "In most cases, the third wire (green) AC equipment ground is the preferred choice for ground."

Per ESD Handbook ESD TR20.20-2008 section 5.3.1.7 Electrical Considerations "[Rtg is] The most important functional consideration for worksurfaces. This establishes the resistance of the primary path to ground for items, placed on the surface. When worksurface materials are being selected, consideration should be given to possible Charged Device Model (CDM) damage to ESD sensitive products. If CDM damage is a concern then setting a lower resistance limit for the worksurface should be considered. Typically, the lower limit for these types of worksurfaces is 1 x 10^6 ohms."