What is NFPA 70E?
NFPA 70E is a safety standard focusing on the “who” rather than the “what” in workplace electrical safety. While the NFPA 70 focuses on safety in the design and installation of electrical systems, NFPA 70E focuses on how the health and safety of operators can be best protected. The NFPA 70E outlines safe work practices in the construction, maintenance, and operation of electrical systems.
NFPA 70E is often considered the de facto standard for electrical safety in the workplace, and the Department of Labor’s Occupational Safety and Health Administration (OSHA) looks to NFPA 70E for fulfilling the performance-based requirements of its standards. The standard was initially developed at the request of OSHA, so while NFPA 70E is not legally mandatory in the way OSHA requirements are, they are closely related. The standard is widely adopted and referenced by electrical engineers, safety professionals, and other stakeholders in the electrical industry.
What’s Covered in the NFPA 70E Standard?
The NFPA 70E standard protects electrical workers by mitigating and reducing electrical safety hazards. NFPA 70E defines these hazards as any “dangerous condition such that contact or equipment failure can result in electric shock, arc flash burn, thermal burn, or arc blast injury.” The three main types outlined in the NFPA 70E are:
Electric shock and electrocution: When an operator is exposed to a current, it passes through their body, either partly or fully. This electric shock can cause pain and burns, and electrocution is when this electric shock is fatal.
Arc flash: When a current leaves its intended path and forms a connection through the air to the ground, or another conductor, it causes an “arc flash.” This happens when the electrical resistance around a conductor breaks down, so the current can follow another low-resistance path. This causes an electrical fireball with high heat and can cause burns and ignite surrounding materials.
Arc blast: An arc flash at high energy levels can have potentially explosive force, known as an arc blast. An arc blast creates extremely high temperatures (up to 35,000 °F), causing life-threatening burns and metal materials to melt. This molten debris poses a further threat to operators in the vicinity. The blast pressure of up to 2,000 lbs./sq.ft can cause significant damage to human bodies internally and externally.
The NFPA 70E outlines the measures to avoid these three potential outcomes when electrical workers are operating. This includes outlining the responsible parties, both owners and operators to different degrees; how work should be carried out in different settings; how to perform risk assessment; and the creation of electrically safe work conditions.
How to Comply with NFPA 70E: Important Notes
There are several elements in the NFPA 70E standard around electrical safety, and we recommend reviewing the full document in-depth to ensure compliance where applicable. Here we’ll look at some of the most important elements for implementing best practices.
Risk Control Method Hierarchy
When following a risk mitigation strategy under NFPA 70E, there is a hierarchy of protective measures that can be taken, which is:
Elimination
Substitution
Engineering controls
Awareness
Administrative controls
PPE
The first three of these are considered the most effective at risk reduction, as they are less likely to be affected by human error and are applied at the source of the potential hazard, unlike the latter three.
Lockout/Tagout
NFPA 70E also outlines the requirements for lockout/tagout (LOTO) procedures around hazardous equipment. This program sees an operator place a physical lock and a tag with their name on it on a piece of hazardous equipment. This happens after they have identified and isolated the energy sources and de-energized the equipment, and prevents another operator from accidentally turning on or re-energizing equipment that someone is working on or close to.
Approach Boundaries
There are several guidelines around the distances that must be maintained from a hazard (e.g., energized equipment). These fall into the following categories:
Prohibited approach boundary: Touching anything inside this area is considered the same as touching live parts.
Restricted approach boundary: This is the limit for approach by qualified persons who must be wearing appropriate personal protective equipment (PPE), i.e., voltage-rate (rubber) gloves and voltage-rated (fiberglass) equipment.
Limited approach boundary: This is the limit at which a worker may be exposed to electrical shock. Non-qualified persons should stay behind this limit unless accompanied by a qualified person and are wearing the appropriate PPE.
Flash Protection Boundary: This is the limit for the potential of receiving burns from an arc flash.
Personal Protective Equipment (PPE): Operators must wear four categories of PPE in various conditions. These are:
Category 1: The lowest level, with a minimum arc rating of 4cal/cm2. It includes face shields, heavy-duty leather gloves and arc-rated (AR) coveralls.
Category 2: This has a minimum arc rating of 8cal/cm2. The PPE includes coveralls rated to 8cal/cm2, heavy-duty leather gloves, AR flash suit hood or face shield to the appropriate rating.
Category 3: This has a minimum arc rating of 25cal/cm2. The equipment includes appropriately rated coveralls, flash suit hoods, and rubber insulating gloves.
Category 4: This has a minimum arc rating of 40cal/cm2. The equipment includes appropriate coveralls, flash suit hoods and gloves.
Additional equipment such as hard hats, parkas, and hearing protection should be used where applicable.
Conclusion
NFPA 70E is a standard outlining the procedures for achieving electrical safety for operators working in hazardous situations. It was requested by OSHA to give better guidance to companies operating hazardous equipment, electrical engineers, safety professionals, and other stakeholders in the electrical industry on achieving electrical safety in the workplace. The standard includes details on risk control, lockout/tagout programs, approach boundaries and PPE.
When designing and installing equipment, including electrical safety equipment such as control panels and switchgear, you should always consider regulations on electrical safety. To learn more about how Enercon can help your equipment and working conditions remain compliant, contact us.