110.11 Deteriorating Agents.
Unless identified for use in the operating environment, no conductors or equipment shall be located in damp or wet locations; where exposed to gases, fumes, vapors, liquids, or other agents that have a deteriorating effect on the conductors or equipment; or where exposed to excessive temperatures.
FPN No. 1: See 300.6 for protection against corrosion.
FPN No. 2: Some cleaning and lubricating compounds can cause severe deterioration of many plastic materials used for insulating and structural applications in equipment.
Some of the off the shelf silicon agents will damage the insulation of some types of conductors.
If silicon is going to be used on electrical conductors or equipment it needs to be listed and labeled for the prupose.