Electrical Safety Basics: A Guide to NFPA 70E
NFPA 70E is a detailed and comprehensive resource that is essential for anyone who has to manage or control workplace electrical hazards.
Personnel who work with electrical equipment need a thorough understanding and complete base of electrical safety knowledge. Electrical work requires diligence and specificity because of the significant, unique nature of the risks involved. In order to help keep workers safe, industry associations collaborate to produce codes and standards that help guide organizations toward agreed-upon best practices.
As a complement to the National Electrical Code, The National Fire Protection Association (NFPA) has assembled standard electrical safety guidelines into 3 chapters and 17 annexes. The NFPA 70E code gives an overview of safety management systems, equipment maintenance, and more granular requirements for specific equipment.
About half of the assembled document is made up of a series of appendices providing further information about topics within the standard. These range from specific procedural requirements (such as limits of approach to program elements), forms, checklists, and useful equations.
Your Electrical Safety Program
NFPA 70E opens with a chapter discussing the parameters of an electrical safety program, either on its own or as part of a comprehensive safety management system.
The requirements are similar to other management system standards such as CSA Z1000, ISO 45001 and ANSI Z10.0, but with a specific focus on electrical hazards. Safety program requirements are laid out, including the usual recommended elements such as hazard assessment and training, as well as a program to monitor the system overall.
The safety program needs a documented audit every three years, with specifics like lockout/tagout procedures and field work audited annually.
(Learn about The 6 Key Elements of an Effective Safety Program.)
Electrical Safety Training
NFPA 70E specifies who needs electrical safety training, when it is needed, and what it should cover. Controls have to be applied to electrical hazards per the national electrical code, but everyone exposed to any leftover risk needs training.
Retraining is required every three years unless there is a substantive change in tasks, technology, or in the case of incidents.
The required worker training relates to:
- Job safety planning
- Identifying electrical hazards
- Assessing the associated risk
- Selecting the appropriate risk control methods from the hierarchy of controls
(Learn about The Top 7 Electrical Hazards and How to Prevent Them.)
Electrical Hazard Controls
NFPA 70E uses a hierarchy of hazard controls that include six levels:
Different variations of this basic structure are used in other hazard assessment standards, however most of them trunk these together into fewer general levels.
Being able to assess risk and apply controls involves workers using specific types of measuring instruments and interpreting their readings. They have to understand the limitations of such devices, as well as when and where to use them. They should be qualified to do any testing required on equipment with an operating voltage greater than 50 volts.
Articles 120-130 of chapter one focus on lockout/tagout procedures and how to proceed when de-energizing is not possible.
These sections cover acceptable lock types, the removal of locks, verifying de-energized states. and acceptable voltages where de-energizing is not required (stable at less than 50 volts). It contains a good amount of detail about applying locks, which locks to use, how and when to remove them, how to discharge stored energy such as in capacitors, and requirements for grounding equipment while it is serviced.
Article 130 describes the processes for working on equipment when it can’t be de-energized, as well as the criteria under which such work is allowed. For tasks such as trouble shooting, working in a de-energized state isn’t feasible, but it is the employer’s responsibility to demonstrate infeasibility. Considering the extra hazards energized work poses, the standard lays out how to permit and document such work and requires that it has suitable justification.
A detailed table of task types requiring arc-rated apparel is included in Section 130, as well as other requirements stemming from the analysis. If an exposure to shock or arc is determined, employers have to set up shock-protection and arc flash approach boundaries.
Depending on the operating voltage and whether it is alternating current (AC) or direct current (DC), shock protection boundaries may be anywhere from 10 to 26 feet, while arc flash boundaries are defined as the distance at which the incident energy equals 1.2 cal/cm2. The employers have to establish rules for who is qualified to enter those areas and under what conditions.
Chapter 2 is comparatively brief and covers maintenance requirements for specific types of equipment. For each category, it includes the type of inspection and some detail on what an inspection should evaluate. The category are:
- General maintenance
- Substations, switchgear assemblies, switchboards, panelboards, motor control centers, and disconnect switches
- Premises wiring
- Controller equipment
- Fuses and circuit breakers
- Rotating equipment
- Hazardous Location
- Batteries and battery rooms
- Portable electric tools and equipment
Safe Work Practices
Chapter 3 lays out safe work practices for settings and equipment with additional requirements compared to the general guidelines laid out in the first chapter.
This chapter outlines safety for working with:
- Electrolytic cells
- Batteries over 50 volts nominal
- Power electronic equipment
- Research and development laboratories
For each of these special categories, NFPA 70E gives specific details about the training required, safeguarding, signage, and responsibility relevant to these applications but atypical for general electrical work.
What remains is a collection of appendices that support the standard. 70E will specify that something must be done, but the annexes is where you look for guidance on how to actually do it. There are samples of forms, guidance on PPE use, design requirements, risk assessment guidelines, and more. The reader should not have to do much extra work to seek out additional resources since they have been selected and included in 70E itself.
NFPA 70E is an essential document when managing and controlling electrical risks on site. It is a comprehensive and easy to use resource. If you have electrical hazards in your workplace, consult the standard and understand your obligations. You owe it to your workers to know how to keep them safe.