In the late ’70s to early ’80s, the first arc flash suits began to appear on the market (Photo 1), most of which were made from double-layer 6 oz/yd2 meta-aramid and featured polycarbonate (plastic) windows for the face shield. These suits were considered state-of-the-art until 1996 when arc testing of clothing and PPE began.
However, it didn’t take long for the shortcomings of this type of arc flash protection clothing and PPE to become evident, especially at higher values of incident energy. During arc flash testing, it was found that the polycarbonate window would actually fail at a very low value of incident energy (approximately 1.5 cal/cm2), causing it to melt. These clear face shields have no arc rating. If you examine the garment label (click to see Photo 2), you’ll also see it lacks the required markings (ATPV, ASTM F1506, and NFPA 70E).
Clothing that has an arc rating but doesn’t comply with today’s labeling requirements is not considered arc-rated. An arc rating by itself does not necessarily indicate compliance with the required national standards, and the company using it may be at risk for citation from OSHA.
Photo 3a (click here to see Photo 3A) shows the label from a garment that seems to have an arc rating, but the label inside (Photo 3b) only states the garment meets NFPA 2112, which is protection against flash fires, not arc flash. Clothing can be dual-rated for compliance with ASTM F1506/NFPA 70E and NFPA 2112, but it has to state this on the label.
Unrated arc flash clothing and PPE present a very real threat to the well-being of the person wearing it. Those wearing it must not be allowed to work on or near any electrical power system or device that may be energized.
White is director of training for Shermco Industries in Irving, Texas. He can be reached at [email protected].
