A few days ago, I received a question regarding exit signage. A customer who was evaluating photoluminescent options wanted to be compliant with OSHA’s 1910.37(b)(6) standard; and naturally, as inexpensively as possible. With so many choices available for exit signage, and a difficult economic climate which has most companies looking to save on costs wherever possible, it’s all too tempting and easy to grab the nearest, cheapest glowing exit sign and slap it up. It’s certainly no help that, as anyone who has reviewed nearly any standard will attest, standards are often written in confusing, long-winded, technical, and circular language with definitions not consistent from one to the next. While not impossible to decode, it requires a concentrated effort of digging, time and, moreover, patience. Who has that?! Lucky for you - me!
There appears to be the most confusion surrounding photoluminescent signs, which is where this blog entry will be primarily focused. We’ll dissect, in plain language, the relevant standards to reveal if, and which, photoluminescent (what is refer to in lay terminology as ‘glow-in-the-dark’) exit signs qualify as “OSHA compliant”.
We’ll start by looking at the specific standard the customer was concerned with - §1910.37(b)(6).
1910.37(b)(6) Each exit sign must be illuminated to a surface value of at least five foot-candles (54 lux) by a reliable light source and be distinctive in color. Self-luminous or electroluminescent signs that have a minimum luminance surface value of at least .06 footlamberts (0.21 cd/m2) are permitted.
It’s easy to get caught up here in the technical aspects of the material you are evaluating and get overwhelmed with thoughts like, “What’s a footlambert. And where is that on my tech data sheet?” But take a step back. The first thing to address is ensuring terms are properly understood - that we have the same understanding of their meaning as OSHA. These are provided in § 1910.34.
Electroluminescent means a light-emitting capacitor. Alternating current excites phosphor atoms when placed between the electrically conductive surfaces to produce light. This light source is typically contained inside the device.
Self-luminous means a light source that is illuminated by a self-contained power source (e.g., tritium) and that operates independently from external power sources. Batteries are not acceptable self-contained power sources. The light source is typically contained inside the device.
What should stand out here is that OSHA does not directly address photoluminescent signs (So, lucky you, it doesn’t even matter what a footlambert is!). However, we must look further to see whether this means they are not permitted by OSHA, or if perhaps they are covered under another standard. What we find is § 1910.35.
1910.35 OSHA will deem an employer demonstrating compliance with the exit-route provisions of NFPA 101, Life Safety Code, 2009 edition, or the exit-route provisions of the International Fire Code, 2009 edition, to be in compliance with the corresponding requirements in §§ 1910.34, 1910.36, and 1910.37 (incorporated by reference, see section § 1910.6).
So, if we find photoluminescence to be compliant with either of the two mentioned codes, then by default, it will be compliant with OSHA.
Again for the next two standards, we are going to focus in on those relating to photoluminescence. And also pull out the related definitions.
1011.4 Internally illuminated exit signs. Electrically powered, self-luminous and photoluminescent exit signs shall be listed and labeled in accordance with UL 924 and shall be installed in accordance with the manufacturer's instructions and Chapter 27 of the International Building Code. Exit signs shall be illuminated at all times.
Self-luminous. Illuminated by a self-contained power source, other than batteries, and operated independently of external power sources.
Photoluminescent. Having the property of emitting light that continues for a length of time after excitation by visible or invisible light has been removed.
7.10.7 Internally Illuminated Signs.
220.127.116.11 Listing. Internally illuminated signs shall be listed in accordance with ANSI/UL 924…
18.104.22.168 Photoluminescent Signs. The face of a photoluminescent sign shall be continually illuminated while the building is occupied. The illumination levels on the face of the photoluminescent sign shall be in accordance with its listing. The charging illumination shall be a reliable light source, as determined by the authority having jurisdiction. The charging light source, shall be a type specified in the product markings.
22.214.171.124 Internally Illuminated. Refers to an illumination source that is contained inside the device or legend that is illuminated.
3.3.193 Photoluminescent. Having the ability to store incident electromagnetic radiation typically from ambient light sources, and release it in the form of visible light. [301, 2008]
3.3.223 Self-Luminous. Illuminated by a self-contained power source and operated independently of external power sources.
Reviewing both the International Fire Code and the NFPA Life Safety Code, reveals that photoluminescent signs are permitted as long as they are listed UL924 and are installed and lighted according to standard.
Therefore, by way of reference, photoluminescent exit signs that meet UL924 are compliant with OSHA standards.
(Obligatory Disclaimer: I am not a representative of OSHA, NFPA, or ICC. Nor am I a lawyer, fire marshal, supreme being, contractor, gymnast, or authority governing exit signage. This post relates specifically to the sign material. Other requirements, such as installation and design, need to be met for full compliance. The information and interpretation provided is that of my limited human nature and therefore subject to error and misinterpretation. Additional requirements for exit signage can vary by country, state, county, municipality, neighborhood association and spousal opinion. Please consult the proper authority in your area.)
Now, don’t forget there are other options for exit signs as well, including lighted and self-luminous. And there is also a use in egress pathway marking for photoluminescent materials that don’t make UL924 listing (in some locations - see above disclaimer!), so don’t discount those.