(913) 667-9896 info@70eConsultants.com

NFPA 70E doesn’t offer a lot of guidance for what a label should look like.  They give us a description of the types of equipment which are to receive a label and a minimum amount of information that is required to be on the label.  Beyond that, there is no required layout.  However, with the help of ANSI Z535, we are able to further determine a proper layout.

Symbols, Signal Words & Colors are chosen based on the likelihood of injury, see below (ANSI Z535.4)
We use “WARNING” up to 40 cal/cm^2 even though a 30 cal/cm^2 will most likely result in death or serious physical injury.  This 40 cal/cm^2 cutoff is standard industry practice (the reason is actually another discussion, some of which is covered here).  Everything greater than or equal to 40 cal/cm^2 is red “DANGER”.
However, we also only use “WARNING” up to 1000V, anything beyond that is red “DANGER”. The reason being, shock hazards are proportional to voltage.  4160V would supply 9x more current to cross your body vs 480V, 12470V would supply 26x more current vs 480V.
Also consider that ANSI requires “Signal word letter height should be at least 50 percent greater than the height of a capital H in the majority of the message panel wording. When space is limited, signal word letter height may be the same as the majority of the message panel wording.”  We have taken this into consideration when designing our labels.
What is actually required on a label?  You can see what NFPA 70E says below:
3 items:  Voltage, arc flash boundary and what PPE should be utilized (indicating the incident energy at respective working distance accomplishes this)
Although not required, we feel that listing PPE is the last line of defense for preparing a worker so we list the actual PPE.  We also list Glove Class.  Our PPE listing comes from NFPA 70E.
Available fault current (short circuit current) is not a requirement for labels in arc flash evaluations, nor for ANSI nor NFPA 70E.
However, it is a requirement for the NEC and it’s super easy for us to apply this at the same time so we do include this on any machine specific labels we create.

Once we’ve met and understand the requirements of national standards we focus on conveying pertinent information.  You can see examples of our labels below, click on each to view it larger.

Ever since arc flash evaluations have become a topic, warning of arc flash has become priority for most when designing electrical hazard labels.  However, shock is much more prevalent and more likely to kill.  For this reason we place the same amount of emphasis on both shock and flash.  We give each the same priority, same font size and same space on our labels.  Now a worker can easily identify both hazards from a safe distance.

Even though NFPA leaves us flexibility, every word, every font size, every color is thought out. We have spent more time on label layout and label application than we ever dreamed of. ANSI Z535 govern’s label layout, they help us choose WARNING vs DANGER. The safety word must be the biggest font on the label and the next biggest size can only be a specific portion of the safety word. The PPE is out of NFPA 70E, each word comes from a standard. Seemingly minor changes to the label might change the intent of the information being conveyed and ultimately become a liability.

We also have a poster available which helps describe each section of a label:  https://www.70econsultants.com/Downloads/RozelLabelPosterv7.pdf

Another one of our posts helps describe how we determine where a label is placed on equipment, see here.

Share This

Share this post with your friends!