Changes are coming to the way we refer to PPE classifications in NFPA 70E. The new NFPA 70E 2015 version, due in Aug/Sept 2014, eliminates the commonly used term HRC (Hazard/Risk Category), which described the level of PPE needed for specific tasks in the PPE tables. Instead, the new NFPA 70E will use the term “arc-rated PPE category,” or simply “PPE level”. It should be noted that HRC has never been required on clothing. ASTM F1506 and other arc flash standards like ASTM F1891 (rainwear), ASTM F2178 (eye and face protection) or ASTM F2675 (gloves) do not require HRC levels — they require that the cal/cm2 garment rating be used.
That being said, the HRCs have become very common on clothing and the levels are still there but will be called PPE categories or PPE levels. The categories remain essentially the same; for example, the current HRC 3, encompassing the range of 25 to 39 cal/cm2, will still be PPE level 3, etc. (see chart). We recommend using something like ARC1, ARC2, etc., to keep something like the HRC and still be clear to the end user if you choose to use these levels on labels.
| Arc Rated Category | Typical Clothing Description (Typical number of layers is given in parentheses) |
Required Minimum Arc Rating of PPE cal/cm2) |
|---|---|---|
 |
FR shirt and FR pants or coveralls, Faceshield/Hardhat (1 layer) natural fiber underlayer allowed |
4 |
 |
FR shirt and FR pants or coverall (1 or 2 layers) Faceshield/Hardhat with balaclava | 8 |
 |
FR shirt and FR pants or coverall plus FR coveralls, or two FR coveralls (2 or 3 layers) with arc flash hood | 25 |
 |
FR shirt and FR pants or coverall plus multilayer flash suit (3 or more layers) with arc flash hood | 40 |
Why did they remove the HRC term? The “risk” has been eliminated from the tables (if you want to use a risk model, you must develop it using Annex F), so there are far more ARC4s than in previous years. There will also be more “No PPE Required” than in previous years because the HRC 0 category has been eliminated (note there are two amendments (TIA’s ) before the NFPA 70E to put this back in, and natural fiber non-melting clothing is required when equipment is open and the calculated hazard is <1.2 cal/cm2).
So you might see more companies changing to ARC (Arc Rated Categories) from HRC.
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What are the PPE requirements when switching MV GIS equipment?
The risk assessment will determine this. Operation may not require anything if the distance is adequate. There used to be some belief that GIS (gas insulated switchgear) could not arc flash but this is untrue but less likely than in some designs. Arc Resistant designs require NO PPE if they are properly installed but most equipment in the field is not of this type.
Most companies use an arc flash suit as posted on the arc flash label or operate by remote. What is your experience?