Electrical safety is a constantly-developing field, and the relevant standards and best practices change frequently. It’s important to stay up-to-date, keeping you and your workers as safe as possible. What are the rules and recommendations for this year?
Rules for Arc Flash Labeling
In the United States, there are three main places to look for arc flash labeling rules:
- OSHA, which regulates general workplace safety
- The National Electrical Code (NEC), which covers the safe installation of electrical systems
- NFPA 70E, which describes safe work practices for existing electrical systems
OSHA’s rules are mandatory; their regulations are federal law. Where an individual state has more specific workplace safety laws, they must be at least as effective as OSHA’s nationwide rules.
The NEC has been incorporated into law on a state-by-state basis, and different states have adopted different editions of the standard over time, but it’s generally considered good practice to follow the most recent edition.
NFPA 70E is not required by law in most jurisdictions, but it represents what OSHA likes to call “Recognized And Generally Accepted Good Engineering Practice.”
What’s Changed for 2017?
OSHA’s rules for electrical safety labeling haven’t changed substantially for several years, and the next edition of NFPA 70E is scheduled for 2018, but a new edition of the NEC was released for 2017. The NEC covers arc flash labels specifically in Article 110.16.
The old edition (from 2014) has a simple, general requirement: equipment that was likely to need “examination, adjustment, servicing, or maintenance while energized” had to be labeled to warn workers about the arc flash hazard. No specific details for the label were required.
This general requirement remained in the 2017 edition, but another, more specific requirement was added. This new requirement applies to service equipment (breakers, switches, fuses, and other related equipment serving as the main control for electrical power in a given building or area) that is rated for 1200 amps or more.
This equipment needs to be labeled with the following details:
- Nominal system voltage
- Available fault current at the protective device
- Clearing time of the protective device (based on the available fault current)
- Date of the label
There is an exception to this new requirement. The new label is not needed if an arc flash label matching “acceptable industry practice” is present. The NEC also includes an informational note explicitly referring to NFPA 70E as an example of “acceptable industry practice” for arc flash labels.
Arc Flash Labeling Under NFPA 70E
The NFPA 70E standard has required labeling for arc flash hazards in some form for over a decade, but each new edition of the standard has expanded or clarified the details that are needed on the label. The label information requirements in the most recent edition (2015) can be found in Article 130.5(D):
- Nominal system voltage
- Arc flash boundary
- At least one of the following:
- Available incident energy and working distance, or the Arc Flash PPE Category (but not both)
- Minimum arc rating of clothing
- Site-specific level of PPE
In these details, the nominal system voltage indicates the general power level of the equipment (and the associated risk of electric shock). The arc flash boundary represents the “stay-back” distance that workers who are not actively working on the equipment should observe. The third requirement, which seems complex, is really just a variety of ways to describe the personal protective equipment (or PPE) that workers need when actively working on the equipment.
ANSI-Style Label Design
Signs and labels that warn workers about a hazard are typically made to follow the ANSI Z535 standard, which describes simple and reliable designs for communicating effectively. Under this standard, labels should have a boldly-colored header that identifies the general severity of the hazard, followed by details in easy-to-read text.
The three headers that are typically used for electrical warnings are “Danger,” “Warning,” and “Caution.”
- Caution labels use a yellow header, and are used for hazards that could cause minor or moderate injuries, but not death or serious injury. Due to the explosive nature of an arc flash, it’s rare for an arc flash label to use this format.
- Warning labels use an orange header, and indicate a more serious hazard, where death or serious injury are possible. Most arc flash labels follow this style.
- Danger labels are reserved for the most extreme hazards, where death or serious injury are almost certain. If equipment cannot be safely worked on while energized, the Danger format is probably appropriate, and lockout/tagout procedures should be used.
Additional Label Elements
Additional details often appear on the same label, often for simple and practical reasons. For example, many labels will include the name and location of the equipment they describe. This makes the process of printing and applying the labels much simpler.
Typical arc flash labels will also feature the date of the analysis that provided the label’s information. This allows a viewer to quickly identify labels that may be out of date, and helps to ensure that changes to the electrical system in a facility are reflected in the labels there. Because arc flash assessments need to be reviewed and revised over time, these dates get even more important as a facility ages.
It’s also common to include the Limited Approach Boundary and Restricted Approach Boundary. These boundaries are “stay-back” distances meant to protect workers from electric shock, and they are described in Articles 130.4(C) and (D) of the NFPA 70E standard.
- Limited Approach Boundary: Generally, workers should stay at least this far from the equipment, unless they have appropriate protective gear and are trained to work safely on that equipment (or are accompanied by someone who has that training).
- Restricted Approach Boundary: This boundary should only be crossed when it’s necessary to perform work on the equipment. Workers crossing this line need to have proper training and protective gear, as well as a written plan for the work they will perform.
Creating Your Arc Flash Labels
If you use electrical analysis software, that software may be able to create label designs automatically. These designs can be printed directly with the DuraLabel line of printers from Graphic Products, providing long-lasting custom signage where and when you need it. If you aren’t using analysis software, you can design your arc flash labels with the labeling software included with DuraLabel printers.