Smoke Alarm Fire Tests
In the UL-FPRF Smoke Characterization Project, researchers determined that smoldering and flaming polyurethane foam produced smoke with characteristics that are different from those used to evaluate smoke alarms under UL 217. These differences combined with the prevalence of polyurethane foam in upholstered furniture and mattresses (the two leading items in fire-related deaths) led UL to request the UL 217 Standards Technical Panel (STP) to form a Task Group to address this issue. In response, the STP formed a UL-led Task group composed of 24 smoke alarm researchers, authorities having jurisdiction, and smoke alarm manufacturer representatives. The Task Group was charged with developing new fire tests to which smoke alarms are evaluated under the standard so as to increase the available egress time for non-specific fires. The new fire tests were required expand the range of smoke signatures from those currently represented by the existing UL 217 test materials.
Starting from the results of the UL-FPRF Smoke characterization Project, the Task Group created a seven step technical plan to achieve success:
Task 1: Identify test target goal(s)
Task 2: Select polyurethane foam test sample(s)
Task 3: Perform analytical and small-scale tests to determine decomposition and smoke generation characteristics
Task 4: Develop smoke data in UL's Fire Test Room
Task 5: Develop test protocol(s)
Task 6: Establish representative test smoke profile(s)
Task 7: Develop proposal(s) for submission to the STP
The Task Group established target performance criteria for the new flaming and smoldering polyurethane foam fire tests that will not inadvertently cause an increase in nuisance alarm frequency (Task 1) and selected five different foams to investigate (Task 2). The selected foams covered a range of densities used in mattresses and upholstered furniture as well as for testing smoke alarms to European requirements (EN 54 Part 7, Annex I Flaming Plastics (Polyurethane) Fire), evaluating the flammability of upholstered furniture (Consumer Product Safety Commission Proposed Rule 16 CFR Part 1634, Upholstered Furniture Action Council, ASTM E 1353), and evaluating residential sprinklers (UL 1626).
In Tasks 3 and 4, UL investigated the smoke produced by the different foams and how sample size, geometry, density, mode of combustion, and mode of heating impacts smoke particle size, count distribution and smoke concentration build-up rates. This work earned the UL research team the inaugural Ronald K. Mengel award for Best Detection Presentation at the Fire Protection Research Foundation's annual Fire Suppression, Detection and Signaling Research and Applications Technical Working Conference (SupDet).
Based on these results, the Task Group selected the foam, sample dimensions, and heating method to move forward in the pursuit of a flaming foam fire test and a smoldering foam fire test.
With the establishment of the foam test sample and test protocols (Task 5), UL repeated each of the two fire tests more than 25 times to define test consistency limits over a six month period. Links to the repeatability trials data follow.
Data file overview (*.xls, 42 kb)
Flaming tests
Flaming tests - raw fire test room data (*.html, 242 kb)
Flaming tests - raw smoke particle data (*.sws, 181 kb)
Flaming tests - raw gas data (*,spc, 507 Mb)
Flaming tests - processed data (*.xlsx, 3.3 Mb)
Smoldering tests
Smoldering tests - raw fire test room data (*.html, 589 kb)
Smoldering tests - raw smoke particle data (*.sws, 361 kb)
Smoldering tests - raw gas data (*,spc, 1.4 Gb)
Smoldering tests - processed data (*.xlsx, 8.7 Mb)
Now in the final stages of developing the test protocols, the Task Group is investigating various approaches to uniformly disperse the smoke generated by smoldering foam in order to reduce alarm location dependency during the course of testing. Results from this investigation can be accessed through the following link.
Smoldering foam smoke uniformity test data (40 Mb)
In parallel with this effort the Task Group is defining the smoke alarm activation criteria for the two new fire tests (Task 6). Once these have been defined, the Task Group will submit the developed test protocols (including test sample specifications) to the UL 217 STP for review and consideration.
