NESC sets enforceable safety standards for the installation, operation, and maintenance of electric supply and communication systems, focusing on arc hazard protection, approach distances, and utility worker safety under state-adopted regulations.
Adoption of the NESC varies by state. In areas where the code has been adopted, it is enforceable as law. The most up-to-date source for information on NESC adoption by state is available directly from the IEEE website:
The NESC is revised every 5 years.
Most changes to the NESC 2012 will occur in Part 4: Rules for the Operation of Electric Supply and Communications Lines and Equipment, with a few significant issues identified:
Arc Hazard:
- The 2012 edition will specifically include details regarding low voltage, long duration arc exposures (<1000 volts), including a possible new method of calculating these plasma arcs (vs. radiant heat arcs). The new standard might require the employer to conduct a hazard assessment for low voltages (50-1000 volts). The 2012 edition will provide a table similar to the existing tables in the 2007 edition, with additional clarification.
Minimum Approach Distances (MAD):
- Minimum Approach distances will be assessed (guide for maintenance methods on energized power lines). A possible error in the original calculation of the MAD will be assessed in the 2012 edition of the NESC.

