All of the following are used to control static discharge EXCEPT:

Ion generators emit positive and negative ions that neutralize static charges on surfaces and in the air, making them a valid and widely used ESD control device.

Anti-static wrist bracelets and discharge plates safely bleed accumulated static charge from personnel and components to ground, directly addressing ESD.

Maintaining relative humidity between 30 and 55 percent reduces static charge accumulation by allowing charges to dissipate through moist air, a well-established ESD prevention practice.

Isolated grounds, as defined in NEC Article 250.146(D), insulate the equipment ground conductor from the metallic raceway to provide a low-noise ground reference path - their purpose is to reduce electromagnetic interference, not to neutralize or dissipate static charges. ESD control requires mechanisms that actively discharge or neutralize static buildup, which isolated grounds do not accomplish. Installing them as an ESD measure would provide no electrostatic protection.