Many safety labels use either Caution, Warning or Danger with a specific color associated with it.

The U.S. National Electrical Code and NFPA 70E both reference ANSI Z535 to provide guidance regarding effective words, colors and symbols for signs and labels that provide warning about electrical hazards.

Other countries may have a different standard for guidance.

Here is this week's question:

How familiar are you with the ANSI Z535 Series of Standards for Safety Signs and Tags

Not in the U.S. / Doesn't apply
Not Familiar
Know about it
I've read it

The current version of ANSI Z535 is very similar to, if not identical to, the GHS labelling requirements so it is not so drastically different from international standards at all. The biggest difference between the current one and the old standard is dropping the various "shapes" (rhombus I think for warning, rounded rectangle for danger, etc.) and addition of not only a signal word but also a standardized glyph/icon. There are about a dozen glyphs most of which are intended to improve on the old NFPA diamonds by being a little more instructive but unfortunately that means for 99.9% of labels that would go on electrical equipment the glyph will always be just an explamation point...not exactly instructive.

More interestingly is that there are some articles which tested whether or not compliance with ANSI Z535 (among other standards) improved compliance with safety warning signs. It had no effect whatsoever. It was more a matter of particular circumstances than anything.

Anything done to make it simple, reducing opportunity for errors, and easy to follow.

(The facilities I've worked at did not wish to emphasize color coding because that could simply be a distraction, all the labels have been red color band, white background and black font.)

Because of what we read in Z535, we do not produce red danger labels any longer. We do not determine where a situation moves from warning to danger.

Danger signage, as defined in Z535, is used when - "Indicates a hazardous situation that, if not avoided, will result in death or serious injury. The signal word "DANGER" is to be limited to the most extreme situations."

Warning signage is used - "Indicates a hazardous situation that, if not avoided, could result in death or serious injury."

We just finished another site specific PPE plan. The customer wanted their people not to work on anything more than 12 calories, so devices with more than 12 calories were labeled with Danger labels. However at those sites were the client did not want to do site specific PPE, we label above 40 calories as Danger, no energized work permitted.