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NFPA 70E, the standard for electrical safety in the workplace, is published by the National Fire Protection Association (NFPA). The NFPA has served as an authority in the U.S. on fire, electricity and building safety since 1896. The purpose of the standard is to provide a "practical safeguarding of employees during activities such as the installation, operation, maintenance, and demolition of electric conductors, electric equipment, signaling and communications conductors." NFPA 70E is a voluntary consensus standard, not a law. However, the U.S. Occupational Safety and Health Administration (OSHA) recognizes NFPA 70E as a generally accepted industry practice and has referenced it in citations.

Who NFPA 70E covers

NFPA 70E was developed to protect electrical workers in all industries who work on or near energized parts or equipment that are capable of generating an arc flash. Such equipment would include high-voltage switching and grounding gear, panel boards, switchboards, motor control centers, motor starters, metal clad switchgear, transformers, and meters. Common occupations covered under NFPA 70E include electrical maintenance workers, industrial electricians, and machine operators.

What NFPA 70E requires

Flame resistant clothing is addressed in Chapter 1 of the standard, Safety-Related Work Practices. NFPA 70E requires employers to conduct an arc flash hazard analysis to identify a worker's potential exposure to arc-flash energy. The results of the analysis are then used to determining safe work practices, arc flash protection boundaries, and the appropriate level of personal protective equipment. The standard states that all equipment must be de-energized before being worked on unless the employer can demonstrate that de-energizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations. If de-energizing the equipment is not feasible, the employer must establish a "flash protection boundary" which is the minimum distance from an arc source where a person could receive a second-degree burn if an arc flash occurred. When it is determined that an employee must perform electrical work within the flash protection boundary, he or she shall wear protective clothing and all parts of the body within the arc flash protection boundary must be protected. NFPA 70E requires the use of one of two methods for determining the appropriate level of flame-resistant clothing: 1. Incident Energy Analysis - The employer must determine the potential incident energy exposure of the worker in cal/cm ². Based on this analysis, the worker must wear arc-rated flame-resistant clothing with an Arc Thermal Performance Value (ATPV - measured in cal/cm ²), or EBT greater than the potential exposure level. 2. Personal Protective Equipment (PPE) Categories (CAT) - To simplify the process, NFPA 70E has developed a table of common electrical job tasks and determined a PPE category for each task. The table above, adapted from NFPA 70E-2015 (Table 130.7(C)(16)), lists the four PPE categories, corresponding required minimum arc rating of flame-resistant clothing and the Carhartt PPE category color codes.


Look for Carhartt PPE category color codes when viewing our online products. An ATPV/EBT is a rating assigned to flame-resistant clothing indicating the level of protection provided. Higher-weight (e.g., thicker, denser) fabrics typically have higher Arc Flash Rating and provide increased protection (as does the layering of FR clothing). All Carhartt flame-resistant clothing has the ATPV/EBT marked on the inside label for easy reference. The ATPV is expressed in calories per cm2 (CAL/CM²) and represents the thermal exposure from an electric arc that at 50% probability will create a second-degree burn in human tissue. If the ATPV cannot be calculated because the fabric breaks open, the energy causing the fabric to break open is expressed as the Energy of Breakopen Threshold (EBT). The higher the value the greater the protection.


For general industry, NFPA 70E:

  • Mandates that employers conduct a risk assessment to determine the potential arc exposure for employees who work on or near energized parts or equipment. The level of arc exposure is referred to as the ATPV/EBT and is measured in calories/cm² (often called a cal rating).
  • Requires employees to wear flame-resistant clothing with a PPE category rating, equal to or greater than the determined arc hazard.
  • Simplifies the risk assessment and compliance process by creating PPE categories for common tasks an electrical worker would perform. Therefore, an FR clothing item's PPE (CAT) rating determines if that item provides sufficient protection for a particular job. As a result, Carhartt FR clothing carries PPE CAT tags. And, unlike some others, Carhartt PPE CAT tags are externally visible, allowing supervisors and safety officers to easily confirm workers are in compliance with NFPA 70E regulation.

For more information or to purchase a copy of the NFPA 70E standard visit the NFPA web site.

NFPA 2112

NFPA 2112, the standard for flame-resistant garments for protection of industrial personnel against flash fire, is published by the National Fire Protection Association (NFPA). The National Fire Protection Association has served as an authority in the U.S. on fire, electricity and building safety since 1896. The purpose of the standard is to "provide minimum requirements for the design, construction, evaluation, and certification of flame-resistant garments for use by industrial personnel, with the intent of providing a degree of protection to the wearer and reducing the severity of burn injuries resulting from accidental exposure to hydrocarbon flash fires" NFPA 2112 is a voluntary consensus standard, not a law. However, OSHA recognizes NFPA 2112 as a generally accepted industry practice.

Who NFPA 2112 covers


NFPA 2112 was developed to protect industrial workers and primarily those in the oil and petrochemical industries against flash fires. A flash fire is defined as "a fire that spreads rapidly through a diffuse fuel, such as dust, gas, or the vapors of an ignitable liquid, without the production of damaging pressure". Flash fires are unplanned exposures that typically last three seconds or less. NFPA 2112 does not apply to protective clothing for electrical flashes, wildland fire fighting, technical rescue, structural fire fighting, proximity fire fighting, or any fire fighting operations or hazardous materials emergencies.

What NFPA 2112 requires

Organizations must conduct a hazard assessment of the work environment to determine if flammable chemicals are present in quantities necessary to generate a flash fire. If a flash-fire hazard does exist, the requirements for wearing flame-resistant clothing shall be based on the potential hazards that workers are exposed to as part of their work duties. Factors in determining if flame-resistant clothing is required shall include, but not be limited to, the following:

  • The potential for the task being performed to increase the possibility of a flammable release; this could result from a mechanical failure such as a line breaking.
  • The presence of engineering controls designed to reduce exposure to flammable materials present during Operating conditions of the process - that is, potential for flammable fumes or vapors, and so forth.
  • The presence of engineering controls designed to reduce exposure to flammable materials present during normal operations.
  • Accident history. If it is determined that flame-resistant clothing is required, the garments shall comply with the requirements of NFPA 2112 and be labeled accordingly.

In order for garments to be meet NFPA 2112 standards all components of the garment must be tested and certified by a 3rd party. The most common certification is completed by UL. A garment will include a label showing that it is UL Classified. Customers can also check garment certification on the UL website.



For the oil and petrochemical industries, NFPA 2112:

  • Mandates that employers conduct a flash-fire hazard assessment to determine the risk of a flash fire.
  • Requires employees to wear flame-resistant clothing if the potential for a flash fire exists.



The U.S. Occupational Safety and Health Administration's (OSHA) 29 CFR 1910.269 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 the NFPA70E and NESC standards.

Carhartt FR garments that meet NFPA 2112 standards for the oil & gas industry have been classified by Underwriters Laboratories (UL).


Published by the Institute of Electrical and Electronics Engineers (IEEE), the National Electrical Safety Code (NESC) sets the ground rules for practical safeguarding of persons during the installation, operation, or maintenance of electric supply and communication lines and associated equipment. The NESC contains the basic provisions that are considered necessary for the safety of employees and the public under the specified conditions. Although not a federal law (some states do make the NESC law), NESC is a voluntary consensus standard, and is the standard OSHA refers to when abating electrical safety in the utility industry. Although the NESC has been in existence since 1973, the 2007 revision marked the first time that flame-resistant, arc-rated clothing was included as a safety requirement and the 2012 version expanded arc-rated clothing down to lower voltages with complete tables specifying apparel requirements from 4 cal/cm ² through 60 cal/cm ².

Who NESC covers

NESC is specific to the electrical utility industry and "covers the electric supply conductors and equipment . . .(including) electric supply stations, that are accessible only to qualified personnel." NESC basically applies to all electric utility work performed at investor-owned utilities, electric co-ops and municipalities.

What NESC requires

The NESC Rule 410A3 governing the use of flame-resistant, arc-rated clothing for electrical utilities, requires the following:

  • Effective January 1, 2009, the employer shall ensure that an assessment is performed to determine potential exposure to an electric arc for employees who work on or near energized parts or equipment. The 2012 rule added low voltage equipment to the >1000V equipment requirement in 2007.
  • If the assessment determines a potential employee exposure greater than 2 cal/cm² exists, the employer shall require the employee to wear clothing or a clothing system that has an effective arc rating at least equal to the anticipated level of arc energy.
  • When exposed to an electric arc or flame, clothing made from the following materials shall not be worn: Acetate, nylon, polyester, or polypropylene unless arc rated in a blend.
  • The effective arc rating of clothing or a clothing system to be worn shall be determined using Tables 410-1, 410-2, and 410-3 or performing an arc hazard analysis.
  • When an arc hazard analysis is performed, it shall include a calculation of the estimated arc energy based on the available fault current, the duration of the arc (cycles), and the worker distance from the potential hazard.

EXCEPTION : If the clothing required by this rule has the potential to create additional and greater hazards than the possible exposure to the heat energy of the electric arc, then clothing with an arc rating or ATPV less than that required by the rule can be worn. This is normally allowed for uncommon work methods such as helicopter work on live power lines.


For electric utilities, NESC:

  • Specifies that employers conduct a hazard risk assessment to determine the potential arc exposure for employees who work on or near energized parts or equipment.
  • Requires employees to wear flame-resistant clothing with an ATPV, or cal rating, equal to or greater than the determined arc hazard.

For more information, visit the IEEE Standards Association web site


 Original Document Carhartt Online