Content area
Full Text
Last October, the NFPA 101 committee convened. The meeting was a report on comments and the final round of committee voting. It covered proposed changes to NFPA 101, the Life Safety Code, means of egress provisions and corresponding changes in the same section in NFPA 5000, the Building Construction and Safety Code. The committee had to consider more than 150 public comments.
Exit Sign Visibility Demonstration. An observation visibilit) test was conducted to compare three most-common (and approved) types of exit signage. The test involved two sets of signs-one set of fully charged signs (simulating visibility immediately following power loss) and one set operating for 90 minutes as required by NFPA 101. Each sign was electrically operated, tritium and photoluminescent-all of which are permitted by NFPA 101, provided they are listed by UL based on UL 924, Standard for Emergency Lighting and Power Equipment-Observation Visibility Test and Luminance Measurement Visibility Test.
The results demonstrated the superior visibility of electrically operated signs and the barely perceptible performance of the photoluminescent signage. Had any smoke been present, it is expected that the photoluminescent signage would have been imperceptible. Performance of the tritium signage was marginal and did not degrade over the 90-minute period, but introduction of smoke may have significantly reduced visibility.
ASSE's representative believes that NFPA should not have substituted compliance with UL 924 for the standing prescriptive minimum luminance requirements. The UL standard is permissive and may incur negative impacts on building occupant safety in an emergency evacuation situation. The following negative comment was submitted on ASSE's behalf, but it will likely take another cycle before there is a chance to return the code to the original prescriptive requirements. The alternative is to pursue a change in UL 924.
NFPA 101 now references a UL standard that reduces the level of safety for building occupants. Understanding the conditions under which nonelectrically operated signs are tested makes it clear that such testing is performed under relatively ideal conditions. These exit signs tests are predicated on requirements that people (with good visual acuity, normal color vision) remain in darkness for five minutes prior to needing to see an exit sign. Standards for all other egress components are based on all...