The Definition of NFPA 70E

Definition of NFPA 70E

NFPA 70E, the Standard for Electrical Safety in the Workplace, is a consensus standard published by the National Fire Protection Association. It sets out practical requirements to protect workers from electrical hazards, mainly electric shock, electrocution, arc flash and arc blast, during work on or near electrical equipment.

NFPA 70E is updated every three years. It focuses on safe work practices and the electrical safety program, while its companion document, NFPA 70 (the National Electrical Code), covers how electrical systems are designed and installed.

OSHA has not adopted NFPA 70E as a regulation, but OSHA's electrical safety rules in 29 CFR 1910 Subpart S and 29 CFR 1926 Subpart K require employers to protect workers from electrical hazards, and OSHA treats NFPA 70E as a recognized industry practice. In practice, following NFPA 70E is how most employers show they are meeting OSHA's requirements and the General Duty Clause.

Key Requirements of NFPA 70E

Electrical safety program

Employers must have a documented electrical safety program that sets out policies, procedures, risk assessment methods, training, auditing and the responsibilities of employers and workers.

Electrically safe work condition

The standard's first principle is that energized work should be avoided. Before work begins, equipment should be put in an electrically safe work condition: disconnected from all energy sources, locked and tagged out, tested for absence of voltage and grounded where needed. See lockout/tagout.

Justifying energized work

Work on energized equipment is allowed only when de-energizing would create a greater hazard or is not feasible because of equipment design or operational limits, such as some testing and troubleshooting tasks. Energized work generally requires an energized electrical work permit.

Shock risk assessment

The shock risk assessment identifies shock hazards and sets two approach boundaries around exposed energized parts:

• Limited approach boundary: unqualified persons may not cross it unless escorted by a qualified person.
• Restricted approach boundary: only qualified persons using shock protection, such as rated gloves and tools, may cross it.

Arc flash risk assessment

The arc flash risk assessment determines whether an arc flash hazard exists, how likely it is, and how severe it could be. It sets the arc flash boundary, the distance at which a person could receive a second-degree burn. PPE is selected in one of two ways:

• Incident energy analysis: an engineering study calculates the expected incident energy in calories per square centimeter, and PPE is rated above that value.
• PPE category method: tables in the standard assign PPE categories 1 to 4 for common equipment and tasks, within set limits.

Labeling, training and maintenance

Equipment likely to be worked on while energized must be labeled with arc flash information. Workers must be trained as qualified persons for the tasks they perform, with retraining at set intervals. The standard also stresses that poorly maintained equipment can increase the chance and severity of an arc flash.

Applying NFPA 70E in Practice

• Inventory electrical equipment and complete arc flash studies, updating them when the system changes.
• Apply the hierarchy of controls, starting with eliminating energized work.
• Provide arc-rated clothing, face shields, voltage-rated gloves and insulated tools matched to the hazard.
• Use job briefings before every electrical task to review hazards, boundaries and PPE.
• Audit the program and field work regularly.

See electrical hazard for more on the types of electrical injuries.

Example of NFPA 70E

A food processing plant's maintenance technicians routinely opened energized 480-volt motor control centers to troubleshoot faults while wearing only standard work clothes and safety glasses. After an arc flash near miss in which a dropped screwdriver caused a loud flash and scorched a panel, the plant hired an engineering firm to complete an arc flash study.

The study found incident energy levels requiring PPE category 2 or higher on most panels. The plant labeled all equipment, bought arc-rated clothing and face shields, trained technicians as qualified persons, introduced energized work permits and changed its default practice to lock out and test before troubleshooting wherever possible.

Frequently Asked Questions: NFPA 70E

Is NFPA 70E required by law?

It is not an OSHA regulation, but OSHA uses it as evidence of recognized hazards and accepted practices. Following it is the most common way to meet OSHA's electrical safety requirements.

What is the difference between NFPA 70 and NFPA 70E?

NFPA 70, the National Electrical Code, covers the safe design and installation of electrical systems. NFPA 70E covers safe work practices for people working on or near those systems.

How often should an arc flash assessment be reviewed?

NFPA 70E calls for the arc flash risk assessment to be reviewed at least every five years and whenever major changes are made to the electrical system.