Maybe its time to look at this code item. It seems that this code item has been in the NFPA 99 code since 1934 (Anesthetic Gases and Oxygen NFPA 565) and the wording has not changed since 1951 (NFPA 565 standard).
I am not sure if a change or additional clarification is needed or not in the NFPA 99 code, but an educational discussion about the differences between grounding and bonding, current status of grounding and bonding potentially used in medical gas and vacuum distribution systems today, and NEC and NFPA electrical experts views on this subject would be a good start.
Today NFPA 99, 2018 definition for grounding:
3.3.68 Grounding. See 3.3.69, Grounding System.
3.3.69* Grounding System. A system of conductors that provides a low-impedance return path for leakage and faultcurrents. (ELS)
No definition of BONDING found in the NFPA 99.
NEC defines grounding as, "Establishing a connection, whether intentional or accidental, between an electrical circuit or equipment and the earth or to some conducting body that serves in place of the earth." Grounding provides a path for conducting electrical energy to earth to prevent arcing, heating, or explosion during a lightning strike.
NEC defines bonding as, "The permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed." The primary purpose of bonding is to equalize ground potential of, and eliminate static discharge between, equipment. If a potential difference exists between two objects connected by a conductor, electrons will flow along the conductor from the negatively charged object to the positively charged object, damaging electronics in its path. The flow of electrons happens until the two charged objects are equalized and the potential difference no longer exists.
