Enhanced Safety Standards Released: UL 217, UL 268

Standards available:

Standard UL 217 

Standard UL 268 

UL conducts research and convenes industry experts through its Standards Technical Panels. As leaders in fire safety and fire research, UL worked with industry to revise the requirements of its smoke alarm standards.

UL conducted a Smoke Characterization Project for the National Fire Protection Research Foundation (NFPRF) to better understand how different types of fires triggered smoke alarms. Smoke particles from a flaming fire and smoldering fire differ in how they burn and trigger alarms. The results of the smoke characterization project demonstrated a need to develop test methods for smoldering and flaming polyurethane foam; in addition to the smoldering and flaming wood and paper tests already in the standard.

There were more than 250 revisions to the standards. Many of the revisions reflect updates to keep pace with technological advancements of smoke alarms and smoke detectors as well as to respond to new fire conditions. The most significant changes were the addition of three new fire tests – two polyurethane foam fire tests and a cooking nuisance alarm test. Smoke Alarms and the Modern Residence Fire

The next generation of smoke alarms and smoke detector systems that comply with the Enhanced Standards may be equipped with more advanced sensors or use several sensors (multi-criteria) and algorithms that will be capable of distinguishing the difference between a smoldering or flaming fire and cooking smoke. This can be accomplished based on the differences in smoke particle size, quantity, gas concentrations and color between fires and cooking aerosols. Advancements in detector sensor design and software algorithms have made this possible. While it is difficult to eliminate all nuisance alarms, it is anticipated that the next generation products will greatly reduce nuisance alarms due to cooking.


read more about the revised standard