NFPA 70E Standard for Electrical Safety in the Workplace

What is the Standard?

NFPA 70E is a standard of the National Fire Protection Association (NFPA) that addresses electrical safety requirements for employees in the workplace and details how to protect workers from the heat of electric arc exposures. The purpose of the standard is to provide a practical safe working area for employees relative to the hazards arising from the use of electricity. Specifically, the standard addresses safety of workers whose job responsibilities entail interaction with electrical equipment and systems with potential exposure to energized electrical equipment and circuit parts.

This standard addresses the safeguarding of employees from the hazards associated with electrical energy during activities such as the installation, inspection, operation, maintenance, and demolition of electric conductors, electric equipment and assists in complying with OSHA 1910 Subpart S and OSHA 1926 Subpart K.

NFPA 70E describes how to protect electrical workers from three kinds of electrical hazards:

  • Electric shock and electrocution
  • Arc-flash (electrical fireball)
  • Arc-blast (electrical explosion at high energy levels)

4-Step Safety Strategy
NFPA 70E outlines a four-step approach to electrical safety:

  1. TURN OFF THE POWER. Work de-energized, whenever possible. However, since this isn’t always feasible, when working on or near exposed live conductors and parts, NFPA 70E requires the following:
  2. LIVE WORK PERMIT. Have the customer sign an Energized Electrical Work Permit.
  3. PLAN THE WORK. Have a written plan for performing the live work safely.
  4. USE PERSONAL PROTECTIVE EQUIPMENT (PPE). This includes flame-resistant (FR) clothing, insulated tools, face shields, and flash suits.

Incident Energy

NFPA 70E requires that the employer shall document the incident energy exposure of the worker when it has been determined that the worker will be performing tasks within the flash protection boundary.  Incident energy is the amount of thermal energy impressed on a surface, a certain distance from the source, generated during an electrical arc event. Incident energy is expressed in calories per square centimeter (cal/cm2).

4 PPE Categories

NFPA 70E includes four PPE categories.  Each category has a minimum arc rating for protective clothing:

PPE Category Black Stallion Rating Protective Clothing Minimum Incident Energy Level
1 ARC 1
  • FR long sleeve shirt
  • FR pants
  • FR coveralls
  • Head protection
  • Foot protection
  • Eye protection
  • Arc flash rated gloves
4 cal/cm2
2 ARC 2
  • T-shirt
  • FR long sleeve shirt
  • FR pants
  • FR coveralls
  • Face shield
  • Cotton underwear
  • Foot protection
  • Eye protection
  • Arc flash rated gloves
  • Hearing protection
8 cal/cm2
3 ARC 3
  • T-shirt
  • FR long sleeve shirt
  • FR pants
  • FR coveralls
  • Flash hood
  • Cotton underwear
  • Foot protection
  • Eye protection
  • Arc flash rated gloves
  • Hearing protection
25 cal/cm2
4 ARC 4
  • T-shirt
  • FR long sleeve shirt
  • FR pants
  • FR coveralls
  • Flash hood
  • Cotton underwear
  • Foot protection
  • Eye protection
  • Arc flash rated gloves
  • Hearing protection
40 cal/cm2
PPE Category 1
Black Stallion Rating ARC 1
Protective Clothing
  • FR long sleeve shirt
  • FR pants
  • FR coveralls
  • Head protection
  • Foot protection
  • Eye protection
  • Arc flash rated gloves
Minimum Incident Energy Level 4 cal/cm2

PPE Category 2
Black Stallion Rating ARC 2
Protective Clothing
  • T-shirt
  • FR long sleeve shirt
  • FR pants
  • FR coveralls
  • Face shield
  • Cotton underwear
  • Foot protection
  • Eye protection
  • Arc flash rated gloves
  • Hearing protection
Minimum Incident Energy Level 8 cal/cm2

PPE Category 3
Black Stallion Rating ARC 3
Protective Clothing
  • T-shirt
  • FR long sleeve shirt
  • FR pants
  • FR coveralls
  • Flash hood
  • Cotton underwear
  • Foot protection
  • Eye protection
  • Arc flash rated gloves
  • Hearing protection
Minimum Incident Energy Level 25 cal/cm2

PPE Category 4
Black Stallion Rating ARC 4
Protective Clothing
  • T-shirt
  • FR long sleeve shirt
  • FR pants
  • FR coveralls
  • Flash hood
  • Cotton underwear
  • Foot protection
  • Eye protection
  • Arc flash rated gloves
  • Hearing protection
Minimum Incident Energy Level 40 cal/cm2

What type of electrical work is not covered under NFPA 70E?

NFPA 70E does not address safe work practices specific to installation, maintenance and operation of utility transmission and distribution systems. There are some facilities and installations under utility control in which application of NFPA 70E may be appropriate. Examples include office buildings, warehouses, garages and maintenance shops.

Related Articles

To learn about the causes of an arc flash, read our article, What is an arc flash?
To see all of our NFPA 70E certified gloves and garments, visit our ARC FLASH page.
To learn more about the Arc Flash Boundary, read our article, What is an Arc Flash Boundary?

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Proud Member of Industry Groups & Associations

CONNECT WITH US

10747 Norwalk Blvd.
Santa Fe Springs, CA 90670
(800) 527-3826
info@revcoindustries.com

Monday-Friday: 7am-4:30pm (PST)

CONNECT WITH US

10747 Norwalk Blvd.
Santa Fe Springs, CA 90670
(800) 527-3826
info@revcoindustries.com
Monday - Friday: 7am - 4:30pm (PST)

Proud Member of Industry Groups & Associations

CONNECT WITH US

10747 Norwalk Blvd.
Santa Fe Springs, CA 90670
(800) 527-3826
info@revcoindustries.com

Monday-Friday: 7am-4:30pm (PST)

CONNECT WITH US

10747 Norwalk Blvd.
Santa Fe Springs, CA 90670
(800) 527-3826
info@revcoindustries.com
Monday - Friday: 7am - 4:30pm (PST)
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