The Standards Council of the National Fire Protection Association, Inc. (NFPA) announced on January 7, 1976, the formal appointment of a new electrical standards development committee. Entitled the Committee on Electrical Safety Requirements for Employee Workplaces, NFPA 70E, this new committee reported to the Association through the National Electrical Code Technical Correlation Committee. This committee 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.
The committee found it feasible to develop a 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 visualized as consisting of four major parts: Part I, Installation Safety Requirements; Part II, Safety-Related Work Practices; Part III, Safety-Related Maintenance Requirements, Part IV, Safety Requirements for Special Equipment.
The new standard was named NFPA 70E, Standard for Electrical Safety Requirements for Employee Workplaces. The first edition was published in 1979 and included only Part I. The second edition was published in 1981. It included Part I as originally published and a new Part II. In 19843, the third edition included Part I and Part II as originally published and a new Part III. In 1988, the fourth edition was published with only minor revisions. The fifth edition, published in 1995, included major revisions to Part I, updating it to the 1993, National Electrical Code (NEC). In Part II of the fifth edition, the concepts of "limits of approach" and establishment of a "Flash Protection Boundary" were introduced. In 2000, this sixth edition includes a complete Part I update to the 1999 NEC, as well as a new Part IV. The seventh edition, published in 2004, reflects several significant changes to the document. The major changes emphasize safe work practices.
Definitions (Article 100)De-energized - Free from any electrical connection to a source of potential difference and from electrical charge; not having a potential different from that of the earth. The term de-energized describes an operating condition of electrical equipment. The term should be used for no other purpose. De-energized does not describe a safe condition.
Electrical Hazard - A dangerous condition such that contact or equipment failure can result in electric shock, arc flash burn, thermal burn, or blast. FPN: Class 2 power supplies, listed low voltage lighting systems, and similar sources are examples of circuits or systems that are not considered an electrical hazard.
Electrical Safety - Recognizing hazards associated with the use of electrical energy and taking precautions so that hazards do not cause injury or death.
Electrically Safe Work Conditions - A state in which the conductor or circuit part to be worked on or near has been disconnected from energized parts, locked/tagged in accordance with established standards, tested to ensure the absence of voltage, and grounded if determined necessary.
Enclosure - The case or housing of apparatus, or the fence or walls surrounding an installation to prevent personnel from accidentally contacting energized parts, or to protect the equipment from physical damage.
Energized - Electrically connected to or having a source of voltage.
Equipment - A general term including material, fittings, devices, appliances, luminaires (fixtures), apparatus, and the like used as a part of or in connection with, an electrical installation.
Limited Approach Boundary - An approach limit at a distance from an exposed live part within which a shock hazard exists.
Listed - Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that the equipment, material, or services either meet appropriate designated standards or has been tested and found suitable for a specified purpose.
Prohibited Approach Boundary - An approach limit at a distance from an exposed live part within which work is considered the same as making contact with the live part.
Qualified Persons - One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training on the hazards involved. The definition of the term qualified person had been modified in the 2004 edition of NFPA 70E to include safety training. No longer is it adequate for an electrical worker to be "familiar with the hazards involved"; the electrical worker of today also must have safety training on the hazards involved.
Shock Hazard - A dangerous condition associated with the possible release of energy caused by contact or approach to live parts.
Unqualified Persons - A person who is not a qualified person. Workers who might be exposed to an electrical hazard as a work task is performed must be trained to recognize that a hazard exists and how to avoid that hazard. Any person who has not received specific training is an unqualified person. A worker who has been trained to perform a task might be qualified to perform that task and still be unqualified to perform any other task. The characteristics of being qualified and unqualified are task dependent.
Utilization Equipment - Equipment that utilizes electric energy for electronic, electro-mechanical, chemical, heating, lighting, or similar purposes.
Voltage (of a Circuit) - The greatest root-mean-square (RMS) (effective) difference of potential between any two conductors of the circuit concerned. The voltage of the circuit of a 2-wire feeder or branch circuit (single phase and the grounded conductor) derived from these systems would be the voltage between the two conductors at the lower voltage (i.e., 277 volts or 120 volts). The same applies to DC or single-phase, 3-wire systems where there are two voltages.
Working Near (Live Parts) - Any activity inside a Limited Approach Boundary. The Limited Approach Boundary is the outmost boundary of an activity of a person working near live parts and cannot be crossed by an unqualified person unless escorted by a qualified person. Persons outside the Limited Approach Boundary might be within the Flash Protection Boundary, making them susceptible to a second-degree burn. Workers must consider all of the hazards and how they are related to be properly protected.
Working On (Live Parts) - Coming in contact with live parts with the hands, feet, or other body parts, with tools, probes, or with test equipment, regardless of the personal protective equipment a person is wearing.Any work that requires a person to cross the Prohibited Approach Boundary is considered to be working on a live part and is subject to all requirements associated with working on live parts. Note that measuring voltages requires that the Prohibited Approach Boundary be breached, suggesting that measuring voltage exposes a worker to an electrical hazard.
General Requirements for Electrical Safety-Related Work Practices (Article 110)
110.6 Training Requirements
(A) Safety Training
The training requirements contained in this section shall apply to employees who face a risk of electrical hazard that is not reduced to a safe level by the electrical installation requirements of Chapter 4. Such employees shall be trained to understand the specific hazards associated with electrical energy. They shall be trained in safety-related work practices and procedural requirements as necessary to provide protection from the electrical hazards associated with their respective job or task assignments. Employees shall be trained to identify and understand the relationship between electrical hazards and possible injury.
(B) Type of Training
The training required by this section shall be classroom or on-the-job type, or a combination of the two. The degree of training provided shall be determined by the risk to the employee.
(C) Emergency Procedures
Employees working on or near exposed energized conductor or circuit parts. Employees shall be regularly instructed in methods of first aid and emergency procedures, such as approved methods of resuscitation, if their duties warrant such training.
(D) Employee Training
Qualified Person
Such persons permitted to work within the Limited Approach Boundary of exposed live parts operating at 50 volts or more shall, at a minimum, be additionally trained in all of the following:
Unqualified Persons
Unqualified persons shall be trained in and be familiar with any of the electrical safety-related practices that might not be addressed specifically by Chapter 1 but are necessary for their safety.
110.7 Electrical Safety Program
General
The employer shall implement an overall electrical safety program that directs activity appropriate for the voltage, energy level, and circuit conditions.
Job Briefing
Before starting each job, the employee in charge shall conduct a job briefing with the employees involved.
110.8 Working On or Near Electrical Conductors or Circuit Parts
Live Parts - Safe Work Condition.
Live parts to which an employee might be exposed shall be put into an electrically safe work condition before an employee works on or near them, unless work on energized components can be justified according to 130.1.
Live Parts - Unsafe Work Condition.
Only qualified persons shall be permitted to work on electrical conductors or circuit parts that have not been put into an electrically safe work condition.
Safety Interlocks
Only qualified persons following the requirements for working inside the Restricted Approach Boundary as covered by 130.2(C) shall be permitted to defeat or bypass an electrical safety interlock over which the person has sole control, and then only temporarily while the qualified person is working on the equipment. The safety interlock system shall be returned to its operable condition when the work is completed.
Article 130 - Working on or near live parts
130.1 Justification for Work
Shall be put into an electrically safe work condition before an employee works on or near them, unless the employer can demonstrate that de-energizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations.
(A) Energized Electrical Work Permit
(1)Where Required.
If live parts are not placed in an electrically safe work condition (i.e. for the reasons of increased or additional hazards or infeasibility per (130.1), work to be performed shall be considered energized electrical work and shall be performed by written permit only.
(2)Elements of Work Permit
The energized electrical work permit shall include, but not be limited to, the following items:
- A description of the circuit and equipment to be worked on and their location.
- Justification for why the work must be performed in an energized condition (130.1).
- A description of the safe work practices to be employed [110.8(B)]
- Results of the shock hazard analysis[110.8(B)(1)(a)]
- Determination of shock protection boundaries [130.2(B) and Table 130.2(c)]
- Results of the flash hazard analysis (130.3)
- The Flash Protection Boundary [130.3(A)]
- The necessary personal protective equipment to safely perform the assigned task [130.3(B), 130.7(C)(9)(a)]
- Means employed to restrict the access of unqualified persons from the work area [110.8(A)(2)]
- Evidence of completion of a job briefing, including a discussion of any job-specific hazards [110.7(G)]
- Energized work approval (authorizing or responsible management, safety officer, or owner, etc) signature(s)
(3) Exemptions to Work Permit
Work performed on or near live parts by qualified persons related to tasks such as testing, troubleshooting, voltage measuring, etc., shall be permitted to be performed without an energized electrical work permit, provided appropriate safe work practices and personal protective equipment in accordance with Chapter 1 are provided and used.
130.2 (A) Approach Boundaries to Live Parts
A person must be qualified before he or she can cross the Limited Approach Boundary. To cross the Restricted Approach Boundary, in addition to being a qualified person, the person must also wear PPE for protection from shock. The Limited Approach Boundary is intended to restrict the approach of unqualified persons. The Restricted Approach Boundary is intended to restrict the approach of qualified persons.
130.2 (D) Approach by Unqualified Persons
Unqualified persons shall not be permitted to enter spaces that are required under 400.16(A) to be accessible to qualified employees only, unless the electric conductors and equipment involved are in an electrically safe work condition.
130.2(D)(1) Working At or Close to the Limited Approach Boundary
Where one or more unqualified persons are working at or close to the Limited Approach Boundary, the designated person in charge of the work space where the electrical hazard exists shall cooperate with the designated person in charge of the unqualified person(s) to ensure that all work can be done safely. This shall include advising the unqualified person(s) of the electrical hazard and warning him or her to stay outside of the Limited Approach Boundary.
130.2(D)(2)Entering the Limited Approach Boundary
Where there is a need for an unqualified person(s) to cross the Limited Approach Boundary, a qualified person shall advise him or her of the possible hazards and continuously escort the unqualified person(s) while inside the Limited Approach Boundary. Under no circumstance shall the escorted unqualified person(s) be permitted to cross the Restricted Approach Boundary.
130.4 Test Instruments and Equipment Use
Only qualified persons shall perform testing work on or near live parts operating at 50 volts or more. Workers must be trained to understand that they are exposed to shock and electrocution when performing work tasks involving testing. Each qualified person must be trained to understand how to use the specific meter and to understand and interpret its indication(s).
All employees who are qualified persons shall be trained to test for the absence of voltage. Each qualified person must be able to operate each meter that he or she might be expected to use and to interpret any possible meter indication. No voltage test device should be available for use until each qualified person has been trained to use it.
