The use of portable lights or extension cords in any room where pyroxylin plastic is stored shall not be permitted.
No extension cords or other temporary wiring shall be permitted within 25 ft (7.6 m) of any stored consumer fireworks.
Extension cords shall not be used as a substitute for permanent wiring.
Electrical outlets should be installed in sufficient numbers to prevent the use of long extension cords.
Extension cords (even though UL listed) can be too small for certain electrical loads, such as irons and air conditioners.
Extension cords should never be used for permanent connections; they should be used only temporarily.
If fire fighters are to provide worthwhile guidance to the occupant, they should be trained to match the current-carrying capability of the extension cord with the current demand of the electrical loads connected to it.
Electrical Cords. Electrical extension cords should only be used when a flexible, temporary (i.e., less than 30 days) connection is necessary and never for permanent wiring.
Flexible electric cords (e.g., extension cords) should be adequate to carry the anticipated amperage and should be listed. Cords should never be under carpets, rugs, or chair mats.
Cords should be placed in a cord tray to avoid tripping hazards and wear. If additional electrical demand is needed, the local management should correct the condition.
These rules, etc., were found in the NFPA Fire Codes!
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Joe Tedesco, NEC Consultant