In order to improve the detection of fires from synthetic materials and to reduce unwanted alarms, new tests have been developed for smoke alarms.
In addition to the long established tests, beginning in May 29, 2020, all smoke alarms seeking to be listed as complying with the ANSI/UL 217 product standard will have to pass new flaming and smoldering polyurethane (PU) foam tests as well as a new cooking nuisance resistance test. Ultimately the new tests will be added to the ANSI/UL 268 smoke detector product standard with the same effective date. Smoke detection manufacturers are in the process of redesigning or developing new products to meet the new requirements.
The PU fire tests were needed to address changes in materials used for interior furnishings and building materials. Forty years ago, the interior furnishings found in homes, hotel guest rooms, dormitories, and offices were primarily made of natural materials like cotton, wood, wool, linen, or silk. Most furniture available in the last 20 years utilizes polyurethane foam for padding, and polyester or nylon for furniture coverings, carpet, and drapes. The reason for this transition is synthetic materials are less expensive, easier to clean, and more resistant to normal wear and tear than natural materials. Also, during the mid-1980’s, construction methods changed from using solid wood lumber like 2X4’s, 2X6’s, and 2X12’s for studs, trusses, and joists to widespread use of “Engineered Lumber,” which is made from wood and synthetic epoxies. This transition occurred because engineered lumber is less expensive and lighter than real wood, while also being just as strong.
With the widespread use of synthetic materials, the smoke characteristics of fires today are considerably different than in the 1970’s. There are numerous reports that demonstrate that fires from synthetic materials burn hotter and faster than natural materials used in the past. The 2008 National Institute of Standards and Technology (NIST) report titled Performance of Home Smoke Alarms Analysis of the Response of Several Available Technologies in Residential Fire Settings concluded that people today have 3 minutes of available safe escape time in “flaming” fires, compared to 17 minutes in the late 1970’s.
The cooking nuisance resistance test was necessary to meet a new requirement in the 2013 edition of NFPA 72®, National Fire Alarm and Signaling Code. Section 18.104.22.168(5) requires all smoke alarms and smoke detectors installed between 6 feet and 20 feet from a stationary or fixed cooking appliance to be listed for resistance to normal cooking activities, such as pan frying, sautéing, and baking. A future effective date of January 1, 2016 was established to allow for the development of a cooking-resistant test in the product standards and to allow manufacturers time to design and get their products listed. The new requirement was needed because normal cooking activities are the leading cause of unwanted alarms.
For the 2016 edition of NFPA 72, the effective date was changed to January 1, 2019, as the cooking nuisance resistance test had not been finalized. It was estimated that an additional three years would be needed to gather the technical data, develop the performance tests, obtain approval from the UL Standards Technical Panel (STP), as well as to allow time for manufacturers to design, test, and list their products.
The new flaming and smoldering PU foam tests as well as the nuisance resistance test will become part of UL/ANSI 217 for smoke alarms and ANSI/UL 268 for smoke detectors. UL recently announced their certification laboratory will not require smoke alarms or smoke detectors to comply with the new tests until May 29, 2020. An effort is underway to change the date for the 2019 edition of NFPA 72 and to promulgate a tentative interim amendment (TIA) for the 2016 edition of NFPA 72 to align with the May 29, 2020 date in the aforementioned product standards. Because of the NFPA code development processes, no change can be made to the 2013 edition.
At this time there are no smoke alarms or smoke detectors that meet the new tests. As a result, many stakeholders are of the opinion that jurisdictions that have or are in the process of adopting the 2013 or 2016 editions of NFPA 72 need to revise the effective date of section 22.214.171.124(5).