I don't think nitrous is used anymore. There are specific codes governing electrical installations in areas where flammable gases are used medically. For some gases, the resistivity of the floor is specified. For instance the floor must have a high enough resistance value to prevent electric shock by conduction, but must still have enough resistance to prevent the buildup of static charges. I forget the exact values ranges but the code did specify the method of measuring the resistance of the floor. Fortunately much safer gases have been developed.
Bill
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"Why not the best?"
Jimmy Carter