What on earth is an Arc Flash, and how do I choose the right PPE?
Arc Flash clothing and PPE is not an easy product to select. Whilst most electrical PPE (insulated gloves, mats, sleeves) is chosen based on working voltage, Arc Flash is not. Arc flash calculations are complex, time consuming, costly and usually performed by an electrical engineer. Not all organisations have those resources, and some contractors work on 10’s if not 100’s of sites, making it physically impossible to do arc flash calculations on all of the equipment they work on. Here’s a short guide on what all the Arc Flash lingo means, and how to estimate the protection level you need.
What does Flame Resistant (Flame Retardant) mean?
Flame Resistant or Flame Retardant is the property of a material whereby combustion is prevented, terminated, or inhibited. Flame resistance can be an inherent property of a material, or it can be imparted by a specific treatment applied to the material.
What does Arc Rating (Arc Rated) mean?
Arc Resistance or Arc Rating is the maximum Arc Flash incident energy resistance demonstrated by a material prior to break open (a hole in the material) or necessary to pass through and cause with 50% probability a second or third degree burn.
Arc Rating is normally expressed in cal/cm² (or small calories of heat energy per square centimetre).
What’s the difference between Flame Resistant and Arc Rated?
All Arc Rated garments must be flame resistant to pass the arc rating test. Not all Flame Resistant garments would pass an Arc Rated test. Flame Resistance is about resistant to heat, fire and flame. Arc Resistance is about resistance to an exploding switchboard or other electrical apparatus.
What’s the difference between Inherent Flame Resistance and Treatments?
Inherently flame resistant fibers contain an essential characteristic that protects the wearer from an ignition source. Treatments or treated fibers have an applied chemical treatment that changes the original level of flame resistance. These may wash out with laundering, depending the type and quality.