Quick Tips #263.1

The National Fire Protection Association (NFPA) is a nonprofit organization devoted to eliminating death, injury, property and economic loss due to fire, electrical and related hazards. The Occupational Safety and Health Administration (OSHA) and the NFPA have written many standards and regulations that build on one another. In the case of NFPA 70E: Standard for Electrical Safety in the Workplace, the OSHA regulations and NFPA standards work so well together it’s been said that OSHA provides the “shall” while NFPA provides the “how.”

OSHA bases its electrical safety standards (found in 29 Code of Federal Regulations (CFR) Part 1910 Subpart S and 29 CFR Part 1926 Subpart K) on the comprehensive information found in NFPA 70E. 29 CFR 1910.333(a) states that employers must employ safety-related work practices to prevent electrical shock or other injuries resulting from either direct or indirect electrical contact. NFPA 70E is the tool employers use to meet this OSHA requirement. For example, OSHA mandates that all services to electrical equipment be done in a de-energized state. “Working live” can only be done under special circumstances. NFPA 70E defines those special circumstances and sets rigid electrical safety limits on voltage exposures, work zone boundary requirements and necessary personal protective equipment (PPE). (See NFPA 70E-2021 Article 130 and OSHA subpart S part 1910.333(a)(1)-(2) and (c) for complete details.)

It is important to note that NFPA 70E is a voluntary national consensus safety standard published by NFPA primarily to assist OSHA in preparing its electrical safety standards. Federal OSHA has not incorporated NFPA 70E into the Code of Federal Regulations.

History of NFPA 70E

The first edition of NFPA 70E was published in 1979 and contained installation safety requirements borrowed from the National Electric Code. In 1981 safety-related work practice requirements were added. In 1995 “limits of approach” and “arc flash” concepts were introduced. In the 1990s and through 2012 the emphasis was on arc flash PPE requirements. Beginning with the 2015 edition, the focus began to shift from PPE requirements to the employer’s duty to create a comprehensive electrical safety program and integrate it into their occupational health and safety management system (OHSMS). Risk management terminology was defined and all requirements in the standard were harmonized with risk management principles. The hierarchy of risk control methods was introduced in an explanatory/informational note. The 2018 edition continued to evolve to address risk assessment and introduced human factors, such as human error, as part of the shock and arc flash risk assessments. This edition emphasized the need to use the hierarchy of risk controls (moved from an informational note into mandatory text) and explicitly stated that the priority must be the elimination of the hazard. The most notable change for the 2018 edition was that tables and text that specified PPE standards were moved to informational tables or notes and 130.7(C)(14)(b) was added to provide guidance on conformity assessment of PPE.

NFPA 70E-2021

The 2021 edition continues to focus on risk assessment and emphasize the need to follow the hierarchy of risk controls to eliminate and reduce the potential hazards.

Most notable changes to the 2021 edition include:

• Article 110 General Requirements for Electrical Safety-Related Work Practices has been revised to incorporate the general requirements for electrical safety-related work programs, practices and procedures from other articles to emphasize their importance.
• Reference to arc-resistant switchgear has been changed to arc-resistant equipment in Tables 130.5(C) and 130.7(C)(15)(a) to address the use of other types of arc-resistant equipment.
• Modifications to Table 130.5(C) – it now lists tasks as either normal or abnormal as a risk assessment condition, and batteries have been added. Also, a new task has been added as YES for likelihood of an arc flash incident for any condition: “Operation of a CB or switch the first time after installation or completion of maintenance in the equipment.”
• Changes to PPE include the incorporation of ASTM D120 for voltage gloves and the requirement for outer layers of clothing. If an outer layer of clothing is worn it must be arc-rated and the inner layer must meet the calorie requirement of the job task.
• Article 360 Safety-Related Requirements for Capacitors and Annex R Working with Capacitors have been added to addresses specific safety related requirements unique to capacitors.
• Annex D Incident Energy and Arc Flash Boundary Calculation Methods has been revised to refer to IEEE-1584-2018 as a method of calculation.
• Annex F Risk Assessment and Risk Control contains new material that provides guidance on how to select PPE using a battery risk assessment process when multiple hazards are present.
• Annex I Job Briefing and Job Safety Planning Checklist contains comprehensive job-planning checklist to aid in pre-job assessments.

Need for NFPA 70E

NFPA 70E Article 110 identifies the General Requirements for Electrical Safety-Work Practices. One major requirement is performing a risk assessment before any work is started. The risk assessment must address employee exposure to electrical hazards and identify the process to be used by the employee to identify hazards, assess risks and implement risk control according to the hierarchy of risk control methods. The procedure must address the potential for human error and its negative consequences on people, processes, the work environment and equipment.

Article 120 Establishing an Electrically Safe Work Condition requires employers to establish, document, and implement a lockout/tagout program and specify lockout/tagout procedures to safeguard workers from exposure to electrical hazards.

Article 130 Work Involving Electrical Hazards covers requirements for work involving electrical hazards when an electrically safe work condition cannot be established.

To quantify the risk present in the covered work two assessments must be done for each affected electrical equipment piece:

• Shock Risk Assessment – 130.4(A)(1) – (3), and
• Arc Flash Risk Assessment – 130.5(A)(1) – (3)

These assessments must identify the hazards, estimate the likelihood of the occurrence and potential severity of injury or damage to health and determine if additional protective measures are required, including the use of PPE.

Table 130.5(C) Estimate of the Likelihood of Occurrence of an Arc Flash Incident for Alternating Current (AC) and Direct Current (DC) Systems may be used to estimate the likelihood of occurrence of an arc flash event to determine if additional protective measures are required. Tasks are now listed as “normal” or “abnormal” as a risk assessment condition. If likelihood of occurrence does exist (designated as a yes response in the table) appropriate arc flash PPE must be determined by one of two methods:

• Incident energy analysis method – Annex D and 130.5(G), or
• Arc flash PPE category method – 130.7(C)(15)(a) or (b)*

One or the other method must be used, but not both on the same piece of electrical equipment.

*The maximum available fault current, maximum fault clearing times (cycle fault) of overcurrent protective devices and minimum working distance must be known to use this method. If not known an incident energy analysis must be completed.

Article 130.7 addresses requirements for personal and other protective equipment for employees exposed to electrical shock and arc flash hazards when the risk associated with these hazards is not adequately reduced by the first five hierarchy of risk control methods: (1) elimination, (2) substitution, (3) engineering controls, (4) awareness, or (5) administrative controls.

Incident Energy Analysis Method

Annex D provides guidance on completing an incident energy analysis to calculate the incident energy and flash boundary. Once the calculations are completed Table 130.5(G) can be referenced to select appropriate arc-rated clothing and other PPE. It should be noted table 130.5(G) only references two PPE energy levels and corresponding PPE:

• Incident energy exposure equal to 1.2 calories/square centimeter (cal/cm²) up to 12 cal/cm²
• Incident energy exposures greater than 12 cal/cm²

Arc Flash PPE Category Method

The PPE category method first references Table 130.7(C)(15)(a) for AC current applications or 130.7(C)(15)(b) for DC current applications to determine the arc flash PPE category and arc flash boundary based on the equipment being evaluated. The maximum available fault current, maximum fault-clearing time, and minimum working distances for each equipment type must be known and followed to use this Table. If any condition fall outsides the listed parameters or are unknown the incident energy analysis method must be used. Once the arc-flash category is determined, Table 130.7(C)(15)(c) is referenced to identify all PPE needed for each applicable arc-flash PPE category.

Labeling Electrical Hazards

Article 130.5(H) states electrical equipment that is likely to require examination, adjustment, servicing, or maintenance while energized shall be marked with a label containing all the following information:*

1. Nominal system voltage
2. Arc flash boundary
3. At least one of the following:
   1. Available incident energy and the corresponding working distance, or the arc flash PPE category in Table 130.7(C)(15)(a) or Table 130.7(C)(15)(b) for the equipment; but not both
   2. Minimum arc rating of clothing; or
   3. Site-specific level of PPE

*Exception 1: Unless changes in the electrical distribution system(s) render the label inaccurate, labels applied prior to the effective date of this edition of the standard are acceptable if they complied with the requirements for equipment labeling in that standard in effect at the time the labels were applied. 

*Exception 2: In supervised industrial installations where conditions of maintenance and engineering supervisions ensure that only qualified persons monitor and service the system, the information required in 130.5(H)(1) - (3) is permitted to be documented in a manner that is readily available to persons likely to perform examination, servicing, maintenance, and operation of the equipment while energized.

It is important to note the information displayed on the label should only be present based on the method used to determine the arc-flash risk assessment. If the arc-flash PPE category method is used, only the PPE category should appear (1–4). If an incident energy analysis method is used the incident energy (cal/cm²) should appear. Must be one or the other displayed.

All calculations and data on the label must be documented to support the information on the label. The data shall be reviewed for accuracy at intervals not to exceed five years. The owner of the electrical equipment is responsible for the documentation, installation and maintenance of the labels.