The HRC/PPE Categories Chart for Arc Rated FR Clothing
Wearing flame resistant clothing can provide the necessary thermal protection to shield workers from an Arc Flash. Once the source of ignition is removed, the FR garments will self-extinguish, greatly limiting the severity of a burn. In many cases, they can mean the difference between a minor accident and a tragic fatality.
Measuring Arc Flash Heat
Arc Thermal Performance Value (ATPV) is the exposure on a material that results in a sufficient heat transfer through the material for a 50% probability of the onset of a 2nd-degree burn. An ATPV rating is assigned to FR clothing to indicate the level of protection that is required. In other words, the higher the rating (cal/cm2), the greater the protection.
Arc Rated Clothing Flame Resistance Levels
A popular testing method for flame resistance of Arc Flash clothing is to use the HRC – Hazard/Risk Category. This was recently changed to PPE level.
The HRC or PPE level is measured by the minimum amount of calories/cm2. There are four risk levels, and the following chart illustrates the 4 HRC/PPE levels with corresponding clothing and minimum arc ratings.
If you are a little unsure of what cal/cm2 is in regards to heat, the common explanation is: 1cal/cm2 = holding 1 match under your finger for 1 second, similarly, 8cal/cm2 = holding 8 matches under your finger for 1 second.
Connect with us on: