Mike: The Life Safety Code (101-5-10.3) refers to both internally & externally
illuminated signs. 5-10.3.2 requires 5 ft-candles and a contrast ratio of not
less than 0.5. 5-10.3.4 says that if externally illuminated, it must be
continuous (the light cannot be on a switch). 5-10.3.5 requires that they be
iluminated by emergency lighting facilities if required in specific occupancy
chapters but gives an exception for approved self-luminious signs.

It may be more than you were looking for but, I did a search of the UL web
site and came up with the following at URL
http://www.ul.com/auth/tca/tcav4n2.htm :

Finding your way out -- The difference between exit signs and path markers

Exit signs, pathway marking systems and path markers are all considered life
safety devices and they all seem to do pretty much the same thing -- help you
find your way out.

All three are covered by Sections 5-9 and 5-10 of NFPA 101, the Life Safety
Code; Section 1013 of the Uniform Building Code; and Article 700 of the
National Electrical Code. In addition, exit signs alone are also covered in
Section 1023 of the National Building Code and Section 1016 of the Standard
Building Code.

But, there are differences. There are different types of exit signs. And,
there are differences in the types of evaluations UL conducts on each of these
products.

As a result, inspection authorities must be careful: 1) not to accept a path
marker as an exit sign, and 2) to make sure the right type of kit is used to
retrofit exit signs.

Markings for the means or paths of egress in buildings may consist of exit
signs; exit signs and pathway marking systems; or exit signs, pathway marking
systems, and path markers. While exit signs are required by codes, pathway
marking systems and path markers are, for the most part, optional. In
addition, path markers are used only with pathway marking systems and are not
intended to serve as exit signs.

Exit Signs -- UL evaluates exit signs through one of three product categories.
Exit Fixtures (UL category FWBO) are exit signs that are supplied by a single
power source. Though the exit fixture may be connected to both the building
power supply and an emergency generator, the transfer switch is always located
outside the sign unit.

Exit lights, covered in Emergency Lighting and Power Equipment (FTBR), on the
other hand, are powered by two sources. Examples include exit lights with an
AC power source into the exit light and a self-contained battery and charger;
exit lights with two "hot" connections and two "neutral" connections and a
transfer relay within the unit; exit lights with two lamps, each connected to
separate power sources; and exit lights with an AC power source energizing the
primary lamps and a DC power source energizing the emergency lamps. The DC
source is typically supplied from unit equipment consisting of a battery, a
charger and a transfer device.

The National, Standard and Uniform Building Codes require exit lights for many
applications while the Life Safety Code requires exit fixtures for many
applications. If the "occupancy" chapters of the Life Safety Code specify
emergency lighting for certain installations, then exit lights are required.

A third exit sign category is Self-Luminous Exit Signs and Markers (FVZQ).
This applies to exit  signs that are continuously illuminated by
self-contained energy sources and operate independently of external power
sources. Signs powered by tritium, a radioactive source, are covered by this
category.

Photoluminescent exit signs require an external power source -- light -- and
are therefore not covered in this category. Instead, they would be covered in
the FTBR exit light category, but, currently, there are no UL Listings for
photoluminescent exit signs.

Products covered by any of these three sign categories undergo electrical
safety evaluations (fire, shock, etc.), light duration evaluations and
legibility evaluations. Exit signs must be legible from a minimum distance of
100 feet. Self-luminous signs are designated for replacement at stated
intervals as part of their UL Listing evaluations.

Exit fixtures, exit lights and self-luminous signs are all evaluated for
Listing to the requirements of UL 924, Emergency Lighting and Power Equipment.

Path Markers and Path Marking Systems -- Floor Proximity Egress Path Marking
Systems (IMZI), or path marking systems, are supplemental egress marking
systems intended specifically to assist with building evacuation when smoke is
present. These electrical, self- luminous or photoluminescent systems are, in
most cases, optional. They consist of strips, arrows or boxes that provide
"essentially continuous visual delineation of the path of egress." They
undergo UL electrical safety evaluations (fire, shock, etc.) similar to exit
signs. However, their legibility requirements are different to reflect a
different use -- 12 feet in smoke obscuration and 25 feet in clear air, as
opposed to 100 feet in clear air for exit signs.

Floor Proximity Path Markers (INCR), or path markers, are used only for path
marking systems and are Classified by UL with this restriction. They, too, are
optional in most cases, but if used, must be used with path marking systems.
Like exit signs, path markers generally project the word "EXIT," which
accounts for the confusion between the two.

Path markers also undergo UL electrical safety evaluations (fire, shock, etc.)
similar to exit signs. And, again, their legibility requirements are different
from those for exit signs -- 12 feet in smoke obscuration and 25 feet in clear
air. Therefore, they are not suitable as exit signs, as defined by the U.S.
model building and life safety codes and UL's requirements. In particular,
"self-illuminating" path markers should not be confused as self-luminous
signs.

However, exit fixtures, exit lights and self-luminous exit signs can be
suitable for floor proximity installation, if they have received the
additional mechanical tests in UL 924 necessary for UL Listing. These exits
signs are marked "Suitable for floor proximity installation." They are,
nonetheless, still considered exit signs and not path markers.

UL has proposed revising UL 1994, its Standard for Low-Level Path Marking and
Lighting Systems to include new product markings relating to maximum mounting
height, maximum distance between light sources, and installation and mounting
instructions/requirements. UL anticipates adopting these marking requirements
by mid-1996 and making them effective by the
end of 1996.

Retrofit Kits -- Retrofitted exit signs are an increasingly common field
occurrence. Retrofit kits for exit lights are intended only for exit lights
and retrofit kits for exit fixtures are intended only for exit fixtures.
Inspectors should verify that the proper retrofit kit has been installed for
the specific type of sign in use and that all instructions have been followed.
These instructions include
information on the size of sign for which the kit is intended and diffuser
replacement requirements. Currently, UL has Listings for exit fixture retrofit
kits but not for exit light retrofit kits.

There are two categories of retrofit kits for exit fixtures. Retrofit Exit
Fixture Conversions (FWCF) covers UL Classified parts and/or subassemblies
intended only for specified manufacturer models. Inspectors should verify that
UL Classified retrofit kits exactly match the model(s) for which they were
intended. Exit Fixture Retrofit Kits (GGET) are parts or subassemblies
intended for exit fixtures of stated dimensions and other parameters, but are
not limited to specific manufacturers or models.

Because retrofitting can result in energy efficiency for the user, UL expects
that inspectors may see more and more of these retrofits.

For more information about exit signs, path marking systems and path markers,
and retrofit kits, call:

     Steven Altamura in Melville, N.Y., at (631) 271-6200, ext. 22336
     Craig Witt in Northbrook, Ill., at (847) 272-8800, ext. 42831
     Keith Landreth in Research Triangle Park, N.C., at (919) 549-1506
     or Kiran Patel in Santa Clara, Calif., at (408) 985-2400, ext. 32818.

"Michael J. Fox" wrote:

> Can anyone give me reasons why I cannot use phosphorescent exit signs such
> as the Duraglo brand in our buildings? Our AHJ will not accept them and
> says that they do not meet NFPA specifications. All of the buildings that
> we would be using them in have emergency lighting, either by battery pack
> units or by alternate service into the building. We do not want to run
> exposed conduit in some of our aesthetically sensitive buildings and
> chopping into the walls isn't an option.
>
> Any info or suggestions would be appreciated.
>
> thanks,
>
> Michael Fox
> Dep. Fire Inspector
> Yale University
> Office of the Fire Marshal
> 314 Prospect Street
> New Haven, CT 06515
> voice: 203-432-9924
> fax: 203-432-8937
> email: [log in to unmask]