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NFPA 70E and Infrared Inspections of Electrical Distribution Systems

Date: May 01, 2002

R. James Seffrin
Jersey Infrared Consultants

P.O. Box 39, Burlington, NJ 08016


Although infrared inspections of electrical equipment are a widely accepted maintenance procedure, considerable debate exists among thermographers concerning their safe conduct. This paper discusses the National Fire Protection Association, NFPA Bulletin 70E, the Occupational Safety and Health Administration and how they apply to infrared inspections of electrical equipment. 


Infrared inspections of electrical distribution equipment are now a widely accepted maintenance procedure. Since electrical panels must be removed, thermographers often come in close proximity to energized components.

This paper discusses the National Fire Protection Association, NFPA 70E, the Occupational Safety and Health Administration and how they apply to infrared inspections of electrical equipment.

This paper is based upon research of existing standards at the time of publication. It is not intended to cover all standards and situations which a thermographer could encounter in the course of his/her work. Thermographers and their employers must be familiar with all current applicable safety and health standards and should consult with their local OSHA office to ensure compliance.

The National Fire Protection Association

The National Fire Protection Association has led the way to fire safety since 1896. The mission of this international nonprofit organization is to reduce the burden of fire on the quality of life by advocating scientifically based consensus codes and standards, research, and education for fire and related safety issues.

Just before the turn of the century, fire was a major safety and economic issue in North America’s crowded cities and factories. In fact, fire death rates and property loss from fire (relative to gross national product) were six times today’s levels.

Concerned with a lack of consistent sprinkler installation practices, a small group of New England fire insurance leaders and sprinkler manufacturers met in 1895 and recognized the need for one formal set of standards. Soon after, a small group met in New York to begin drafting sprinkler rules, and by March 1896, the draft rules were complete and a committee began organizing. By November 1896, the National Fire Protection Association was created.

Throughout its first 100 years, NFPA’s diverse activities have clustered around the broad themes of fire safety and education, and technological advancement in fire protection, which reflect the original objectives of the organization.

Presently headquartered in Quincy, Massachusetts, NFPA’s membership is over 68,000 people and more than 100 organizations in the United States, Canada and 70 other countries. More than 5300 volunteer members of 205 Technical Committees develop more than 300 codes and standards known collectively as the National Fire Codes®.

The NFPA has no enforcement power; its standards are merely advisory. However, the Association enjoys a unique reputation for its technical accuracy and procedural fairness. Consequently, for many years all levels of government have adopted NFPA standards, giving many of them the force of law.

One of the many NFPA codes that has achieved worldwide recognition, adoption, and enforcement is the National Electric Code® . NFPA 70 addresses proper electrical systems and equipment installation to protect people and property from hazards arising from the use of electricity in buildings and structures.

The History of NFPA 70E

In January 1976, the Standards Council of the National Fire Protection Association, Inc., announced the appointment of a new electrical standards development committee. The “Committee on Electrical Safety Requirements for Employee Workplaces, NFPA 70E” was formed to assist OSHA in preparing electrical safety standards that would serve OSHA’s needs and that could be expeditiously promulgated through the provisions of Section 6(b) of the Occupational Safety and Health Act. OSHA had found that in attempting to utilize the latest edition of NFPA 70, National Electrical Code® (NEC), it was confronted with several problem areas:

(a) Adopting a new edition of the NEC by Section 6(b) procedures would require extensive effort and resources by OSHA and others including public notice, comments, and hearings. Going through the 6(b) procedures might result in requirements substantially different than those of the NEC, thereby creating potential conflict between the OSHA standard and other national and local standards.

(b) The NEC is intended primarily for those who design, install, and inspect electrical installations and it is extremely difficult for the average employer and employee to understand.

(c) Some of the detailed provisions within the NEC are not directly related to employee safety and, therefore, are of little value for OSHA’s needs.

(d) Electrical safety-related work practices and maintenance of the electrical system considered critical to safety are not found in the NEC. However, OSHA must consider and develop these safety areas in its regulations.

This led to the concept that a document be written that would extract suitable portions from the NEC and from other documents applicable to electrical safety. This concept and an offer of assistance was accepted by the Assistant Secretary of Labor in 1975.

A study by committee found it feasible to develop a four-part standard for electrical installations that would be compatible with the OSHA requirements for safety for the employee in locations covered by the NEC.

The new standard was named NFPA 70E, Standard for Electrical Safety Requirements for Employee Workplaces. The new standard was first published in 1979 and contained only Part I. Parts II and III were added in subsequent editions. The February 7, 1995, edition does not include new parts; however, it does contain extensive revisions to previous editions. Part IV has not yet been published.

NFPA 70E is intended to serve a very specific need of OSHA and is in no way intended to be used as a substitute for the NEC. NFPA 70E is intended for use by employers, employees, and OSHA.


The Introduction of 70E is divided into two Parts: I-1 Scope and I-2 Definitions. The Scope reads as follows:

I-1.1 This standard addresses those electrical safety requirements for employee workplaces that are necessary for the practical safeguarding of employees in their pursuit of gainful employment. This standard covers:

(a) Electric conductors and equipment wiring installed within or on buildings or other structures, including mobile homes and recreational vehicles, and other premises such as yards, carnival, parking and other lots, and industrial substations.

(b) Conductors that connect the installations to a supply of electricity.

(c) Other outside conductors on the premises.

I-1.2 This standard does not cover:

(a) Installations in ships, watercraft, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles.

(b) Installations underground in mines.

(c) Installations of railways for generation, transformation, transmission, or distribution of power used exclusively for operation of rolling stock or installations used exclusively for signaling and communication purposes.

(d) Installations of communication equipment under the exclusive control of communication utilities, located outdoors or in building spaces used exclusively for such installations.

(e) Installations under the exclusive control of electric utilities for the purpose of communication or metering; or for the generation, control, transformation, transmission, and distribution of electric energy located in buildings used exclusively by utilities for such purposes or located outdoors on property owned or leased by the utility or on public highways, streets, roads, etc., or outdoors by established rights on private property.

I-1.3 This standard is divided into the following four parts and two appendixes:

Part I, Installation Safety Requirements

Part II, Safety-Related Work Practices

Part III, Safety-Related Maintenance Requirements

Part IV, Safety Requirements for Special Equipment (To be developed at a later date)

Appendix A, Tables, Notes, and Charts (Reserved)

Appendix B, Referenced Publications

Part I, Installation Safety Requirements

Part I of this standard is divided into six chapters dealing with the construction of electrical systems. Since thermography is not construction related, Part II is the applicable section for infrared inspection of electrical systems.

Part II, Safety-Related Work Practices

Part II of this standard is divided into five chapters. It covers electrical safety-related work practices and procedures for employees who work on or near exposed energized electrical conductors or circuit parts. The practices and procedures are intended to provide for employee safety relative to electrical hazards in the workplace.

The employer is responsible for providing the safety-related work practices and training of the employees. The employees are responsible for implementing the safety-related work practices.

There are many references to “qualified” and “unqualified” persons within NFPA 70E. From the standard’s definitions we find:

Qualified person. One familiar with the construction and operation of the equipment and the hazards involved.

Unqualified person. A person who is not a qualified person.

NFPA 70E states that only qualified persons may work on or near energized electric circuits. Since infrared inspections of electrical equipment will often require a thermographer to come in close proximity to exposed live conductors, thermographers must be Qualified Persons in order to comply with the standard.

Safety Training Chapter 2 requires that qualified persons who work on or near energized equipment be trained in the safety-related work practices and procedural requirements as necessary to provide protection from the electrical hazards associated with their respective job or task assignments. They must also be trained in and familiar with:

(a) The skills and techniques necessary to distinguish exposed energized parts from other parts of electric equipment,

(b) The skills and techniques necessary to determine the nominal voltage of exposed energized parts,

(c) The approach distances specified in Table 2-3.3.5 and the corresponding voltages to which the qualified person will be exposed, and

(d) The decision-making process necessary to determine the degree and extent of the hazard and the personal protective equipment and job planning necessary to perform the task safely.

Qualified persons must also be familiar with the proper use of special precautionary techniques, personal protective equipment, insulating and shielding materials, and insulated tools and test equipment.

Qualified persons must also be trained in and familiar with applicable emergency procedures such as the release of victims from contact with exposed energized conductors or circuit parts. They must receive regular training in first aid and resuscitation.

Training may be conducted within the classroom or through on-the-job training.

Electrical Safety Program NFPA 70E states that the employer shall implement an overall electrical safety program that directs activity appropriate for the voltage, energy level, and circuit conditions.

The program must define its principles; the controls by which it will be measured and monitored; and the specific procedures for working on or near exposed energized conductors and circuit parts. It must provide self-discipline for employees and instill safety principles.

Job Briefings Job briefings are required before the start of each job. Briefings are required at least once per shift for repetitive work or more frequently if significant work changes occur. Briefings can be short if employees understand through training and experience the hazards involved; or more extensive if the work is complicated or hazardous or the employee cannot be expected to recognize and avoid the hazards involved in the job.

Conductive Materials, Tools, and Equipment Being Handled Work practices must be employed to safeguard employees when work is performed on or near exposed energized circuits. Work practices must protect employees from direct bodily contact or contact through a conductive object. Work practices must be suitable for the work conditions under which the work is being performed and for the voltage levels of the exposed circuits.

Personal and Other Protective Equipment NFPA 70E states that employees working in areas where there are potential electrical hazards shall be provided with, and shall use, protective equipment that is appropriate for the specific parts of the body to be protected and for the work to be performed.

Protective equipment must be maintained in a safe, reliable, sanitary condition and must be periodically inspected or tested. Employees must wear personal protective equipment for the head, face, neck, chin, eyes, ears, body and extremities when determined necessary by the Hazard/Risk Evaluation Procedure listed in 2-5.1.6.

Nonconductive flame-resistant head protection is required when there is a danger of contact with exposed energized parts or from falling objects. Where there is potential exposure to arc flash burns, or to flying objects, head protection must be supplemented by a cape, scarf, and full face shield or hood with a viewing window.

Eye protection is required to protect from flying or falling objects. Where there is potential exposure to arc flash conditions, such protective equipment must protect the eyes from the resulting thermal and luminous energy.

Employees are required to wear clothing resistant to flash flame wherever there is possible exposure to an electric arc flash. Flash Protection Boundaries are defined in Table 2-3.3.5 or may be calculated from the formulas printed in 2-

Use of Equipment NFPA 70E states that only qualified persons may perform testing work on energized electric circuits or equipment. All test equipment must be visually inspected for external damage and defects prior to each use. Equipment found to be damaged or defective must be removed from service until it is repaired and rendered safe for use. Test equipment must be rated for the circuits being tested and operated only in the environments for which they are designed.

Safety Signs and Tags and Barricades When normally enclosed live parts are exposed for maintenance or repair, they must be guarded to protect unqualified persons from contact with the live parts. The use of safety signs and tags warning about electrical hazards, and barricades are required to warn and protect employees. An attendant is required when signs and barriers do not provide sufficient warning and protection.

Several other work practices are addressed for those who work on or near exposed energized parts. These include lockout/tagout, overhead lines, illumination, confined or enclosed work spaces, conductive material and equipment, portable ladders, conductive apparel, housekeeping duties, and interlocks. Thermographers must comply with all work practices which are applicable to his/her work. Should a thermographer defeat an interlock to gain access to a piece of equipment, the safety interlock system must be returned to its operable condition when the work is completed.

Of the above work practices, the applicability of “Lockout and Tagout” confuses many thermographers. Simply put, Lockout/Tagout is designed to prevent electrocution and injury while a circuit is being worked on.

Since thermography requires that circuits be energized, Lockout/Tagout does not directly affect thermography other than de-energizing certain equipment. Thermographers should be aware of the importance of Lockout/Tagout and must never remove or tamper with tags and locks unless they are qualified to do so.

Part III, Safety-Related Maintenance Requirements

Part III of this standard is divided into eleven chapters dealing with the maintenance of electrical equipment and installations. Since thermography is solely inspection and not maintenance, Part III is not applicable for infrared inspections. 


Presently, NFPA 70E serves as a written safety standard for the inspection of energized electrical distribution systems. While some of the requirements are redundant to OSHA’s 1910, NFPA 70E is more comprehensive.

Since NFPA 70E was developed for the Occupational Safety and Health Administration, it is a standard that OSHA will almost certainly reference. Enforcement seems likely for many if not all principles of NFPA 70E since much of the content of NFPA 70E parallels OSHA 1910.

For those involved in the generation and transmission of electricity, OSHA 1910 Subpart R will continue to serve as a reference standard.

Thermographers and their employers must identify how the NFPA and OSH standards apply to their work and ensure that they are in compliance. Failure to comply can result in fines and criminal penalties.


OSHA Home Page, U. S. Department of Labor, Occupational Safety and Health Administration, http: / /

Public Law 91-596, Occupational Safety and Health Act of 1970, amended November 5,1990.

Occupational Safety and Health Standards for General Industry, Part 1910, U. S. Department of Labor, Occupational Safety and Health Administration,

NFPA Home Page, U. S. Department of Labor, Occupational Safety and Health Administration,

NFPA 70E Standard for Electrical Safety Requirements for Employee Workplaces. © 1995, National Fire Protection Association, 1 Batterymarch Park, P. O. Box 9101, Quincy, MA 02269-9101.


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