Arc Flash Clothing - Frequently Asked Questions



What does Flame Resistant (FR) mean?


Flame Resistant or FR is the property of a material whereby combustion is prevented, terminated, or inhibited following the application of a flaming or non-flaming source of ignition, with or without subsequent removal of the ignition source. Flame resistance can be an inherent property of a material (e.g. Nomex), or it can be imparted by a specific treatment applied to the material (e.g. Banwear).


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.


What key points are most important when choosing FR garments?


ArcSafe X50 Arc Flash Safety ClothingIn choosing the right FR garments for your workforce, there are several qualities that you should consider: thermal protection, static resistance, arc rating, comfort, durability, stability, employee satisfaction, overall appearance, ease of laundry care, and relative cost. But most importantly, it is essential that you choose the FR garments that provide the appropriate level of protection based on your hazard risk analysis.


Why do I need FR clothing? I've never had an accident?


Accidents can happen anytime, anywhere, and to anybody, regardless of past performance. The fact is that equipment breaks, people make mistakes and eventually a situation will arise with the potential of causing serious injury. The use of FR clothing and other personal protective equipment is the last line of defence when these incidents occur.


How does Elliotts FR Clothing help protect against burn injury?


Wearing Elliotts FR Clothing will provide thermal protection, which if exposed to electric arcs or flash fires, will self extinguish after the source of ignition is removed, limiting the degree of burn and body burn percentage. The flame-resistant fabrics are impregnated with chemicals that extinguish flames and help char the fabric. It is not designed to be flame proof; however, it is flame-resistant.


Can the flame-resistant chemicals be washed out?


No. Elliotts FR Clothing is guaranteed to be flame-resistant for the useful life of the garment; regardless of the number of washings provided the garment care instructions are followed.


Will non-treated 100% cotton and other natural fibers help protect against possible burn injury?


Non-treated cotton and wool are flammable fibres. If exposed to electric arcs and flash fires, these materials will continue to burn causing possible severe injury and death.


What is NFPA?


NFPA stands for the National Fire Protection Association, a world-renowned safety and standards setting institution.


What is NFPA70E?


The National Fire Protection Agency's (NFPA) 70E is the Standard for Electrical Safety Requirements for Employee Workplaces. NFPA70E requires employees to wear flame resistant protective clothing wherever there is a possible exposure to electric arc flash. Although it is a voluntary standard, NFPA70E is considered a ?generally accepted industry standard? and thus OSHA will fine companies under the general duty clause, which requires employers to take the appropriate steps to protect workers. NFPA70E is widely accepted throughout general manufacturing as well as the electrical industries.


What is an Arc Rating?


An Arc Rating is the maximum incident energy resistance demonstrated by a material (or a layered system of materials) prior to break-open or at the onset of a second-degree skin burn. Arc rating is normally expressed in cal/cm2 (0.5 to 1 cal/cm2 = hottest part of lighter in 1 sec). An exposure of only 1-2 calories will cause second degree burn on human skin. Typical non-FR workwear can ignite at energies as low as 2 calories.


What is Arc Thermal Performance Value (ATPV)?


Arc Thermal Performance Value is the incident energy on a material that results in sufficient heat transfer through the material for a 50% probability of the onset of a second-degree burn on human tissue. ATPV is a rating assigned to FR Clothing indicating the level of protection provided. Higher fabric weights typically have higher ATPV's and provide increased protection as does the layering of FR Clothing. ATPV is measured in calories per centimeter squared (cal/cm2).


What is a Calorie?


A Calorie is an energy measurement used to characterize the amount of arc flash energy which is required to cause a second degree (blister burn) on human skin. Without protection, according to the Stoll Curve, it takes about 1.2 cal/cm2 to cause a second degree burn.


What is Ablation?


Ablation is defined as the removal of material from the surface of an object by vaporization, chipping, or other erosive processes. The term occurs in space physics associated with atmospheric reentry, in glaciology, medicine and passive fire protection.


What is EBT?


Break open Threshold Energy (EBT) is a rating assigned to FRC indicating the level of protection provided. EBT is used when ATPV cannot be measured due to flame-resistant fabric break open. EBT is also measured in calories per centimeter squared (cal/cm2).


What is Heat Attenuation Factor (HAF)?


This is the amount of heat blocked by the fabric. Even though a fabric may be 100 percent flame resistant, that does not mean it will block all of the heat to which it is exposed. An HAF of 85 percent means that it will block 85 percent of the heat the fabric encounters. This applies to a short burst of arc-flash heat ? typically less than one second. In the event of prolonged heat exposure, the HAF would be much lower.


Is it safe to roll up the sleeves of an FR garment?


FR clothing can only provide protection where it separates the wearer from the ignition source. If the sleeves are rolled up or cut off, the exposed body parts are completely unprotected and will suffer the same injuries as if the garments had never been worn. Some company policies may allow for employees to unbutton their shirts or roll up their sleeves when not working around energized parts or other potential ignition hazards.


What is ASTM F1506?


The American Society for Testing and Materials (ASTM) developed F1506, the Standard Performance Specification for Flame Resistant Textile Material for Wearing Apparel for Use by Electrical Workers Exposed to Momentary Electric Arc and Related Thermal Hazards. This is a pass/fail standard that requires a sample of flame-resistant fabric to self extinguish with a <2 second afterflame and a <6" char length. The FR fabric must also stand up to these requirements after 25 washes/dry cleaning.


What is OSHA 29 CFR 1910.269?


The Occupational Safety and Health Administration?s (OSHA) 29 CFR1910.269 covers the operation and maintenance of electric power generation, control, transformation, transmission and distribution lines and equipment. Part (l) (6) (iii) states: The employer shall ensure that each employee who is exposed to the hazards of flames or electric arc does not wear clothing that, when exposed to flames or electric arcs, could increase the extent of the injury that would be sustained by the employee. This is the only federal law relating to FR clothing for electrical purposes. It is currently being rewritten and is expected to closely mirror NFPA70E. Once approved, FRC requirements would become law.



Arc Flash Protection Clothing - References