In the early 2000’s the NIST Home Smoke Alarm Tests (Dunes II), a set of full-scale experiments, were conducted that examined the performance of currently available smoke alarms to fire scenarios focusing on modern upholstered furnishing fires featuring expanded polyurethane foam cushioning. The concerns were that these materials burn rapidly when flaming and can smolder for extended periods of time and that current technologies, photoelectric and ionization sensing, might not provide sufficient egress time from such fires in residential settings.

Following the results from that study and follow-on studies, there was an effort to develop a new set of fire tests in UL 217/268 to include both flaming and smoldering polyurethane foam fires to provide enhanced performance irrespective of the sensing technology.

These changes were approved and were included in the UL 217 8^th edition (2015). In 2016, these new tests were incorporated into UL 268 7^th edition. Prior to the approval of UL 217 8^th edition, NIST conducted a series of experiments replicating the new fire and nuisance test conditions to assess the performance of a wide sample of smoke alarms on the market at the time. From the results, it was concluded that no current alarms would meet the performance requirements of the new tests and addition of the new tests to the Standard would improve overall detection and provide some nuisance alarm resistance.