The questioner wanted guidance from OSHA about whether or not OSHA would allow the employer to use Table 410-1 of the 2012 National Electrical Safety Code (NESC) to make PPE and equipment selections.

OSHA found that many of the values listed in Table 410-1 are acceptable for compliance because the notes clearly state that those values are based either on testing data or on calculations performed using methods described in IEEE Std 1584-2002. However, the text in notes 7 and 8 suggests that those values in 7 and 8 are NOT based on testing data or generally recognized calculation methods. Therefore, notes 7 and 8 are not acceptable for compliance with 269(1)(8)(ii).

OSHA reviewed Table 410-1 to see if it would meet the requirements in 269(1)(8)(ii), which states, “for each employee exposed to hazards from electric arcs, the employer…make a reasonable estimate of the incident heat energy to which the employee would be exposed.”

OSHA states that it will accept the use of Table 410-1 in the 2012 NESC with respect to the values in that table to which notes 7 and 8 do not apply. They will accept arc-rated protection based on those estimates under 29 CFR 1910.269(1)(8)(v).

It is VERY important to read the notes in these tables clearly.  OSHA will not accept use of the tables which falls outside the notes or parts of the tables which are not based on data.

New Version of ArcPro

A new version of ArcPro 3.0 is coming out soon and will include 3P, DC and arc-in-a-box calculations.  The new version will also include batch processing.

Read the OSHA interpretation for use of NESC 2012 Tables for Arc Flash Hazard Assessment.