Personal Protection Equipment Selection

What determines the appropriate PPE?

The type of PPE required depends on the minimum arc rating as determined by the flash hazard analysis results, the incident energy levels expressed as calories per square centimeter (cal/cm2) expected to be encountered at specific distances.

Arc-Rated vs. Flame-Resistant PPE

All protective clothing and equipment used for the protection from an arc flash event must be "arc-flash" rated and labeled as so by the manufacturer. In previous releases of the NFPA 70E, the term "flame resistant" had been used but is now removed to clarify that the only acceptable rating that will be allowed is the arc flash level. Using the flame resistant term could imply that using PPE made from these materials is adequate when in fact they are not. Note that this refers to arc flash/electrical shock protection and does not rate for arc blast. All arc-rated garments or equipment are always flame resistant—but not all flame resistant garments and equipment is arc-resistant.

A way of identifying arc-rated articles is the cal/cm2 rating on the label.

The OSHA "269" standard (1910.269(l)(6) ) which applies to all work involving electric power transmission, or distribution lines and equipment, whether it be general industry or construction work:

  • Requires that workers be trained in the potential hazards of electric arcs and the flames they can produce by igniting other materials in the area.
  •  Prohibits workers from wearing clothing that, in the presence of an arc, can potentially increase the extent of injury; that is, if the clothing would ignite and continue to burn, or if it melts on the skin. Thus, workers are generally prohibited from wearing clothing materials made entirely of, or blended with, synthetic materials such as acetate, nylon, polyester, or rayon.
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Note that the NFPA 70E 2012 130.5 (B) standard applied the Hazards Risk Categories for item (2) which was replaced for 2015 with the article shown below:

 

NFPA 70E 2015 Article 130.5(C) Arc Flash PPE. One of the following methods shall be used for the selection of PPE. Either, but not both, methods shall be permitted to be used on the same piece of equipment. The results of an incident energy analysis to specify an arc flash PPE Category in Table 130.7(C)(16) shall not be permitted. (1) Incident Energy Analysis Method. (2) Arc Flash PPE Categories Method. (NFPA 70 E 2015)

(1) Incident Energy Analysis Method. The incident energy exposure level shall be based on the working distance of the employee's face and chest areas from a prospective arc source for the specific task to be performed. Arc-rated clothing and other PPE shall be used by the employee based on the incident energy exposure associated with the specific task. Recognizing that incident energy increases as the distance from the arc flash decreases, additional PPE shall used for any parts of the body that are closer than the distance at which the incident energy is determined.

(2) Arc Flash PPE Categories Method. The requirements of 130.7(C)(15) and 130.7(C)(16) shall apply when the arc flash PPE category method is used for the selection of arc flash PPE.

 

 Various_Arc_Flash_PPE.jpg

Figure 1: Various Arc Flash PPE

Courtesy of Dean Thomas, GTRI 

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Figure 2: Arc Flash Suit 40cal/cm2 Label

Courtesy of Dean Thomas, GTRI