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End-of-life is a Problem for Life Safety Products: A Call to Action!

By Mark K. Goldstein, Ph.D.

Even the Sun has a limited life. So does your life safety alarms! Yes, even your smoke alarm has a limited life. Most smoke alarms stay alive and well for ten years. But read your manual to be sure. In carbon monoxide alarms the life is usually from 5 to 7 years depending on the manufacturer. All CO alarms and detectors have limited lives so CO/smoke combination alarms should be replaced according to the CO sensor life. Each instruction manual should alert you to the alarm’s useful life.

All CO sensing technologies (electrochemical, metal oxide and biotechnology) in use today have been in the broad US consumer market from the mid to late 1990's to the present. Some technology such as the fuel cell technology was invented over 172 years ago by Sir William Robert Grove in England. The Biotechnology based SIR technology was invented by Dr. Mark Goldstein in 1989. Taguchi was awarded a Japanese Patent for his tin oxide Metal Oxide Semiconductor (MOS) in 1962.  

It was only in 2009 that end-of-life signals were established by the ANSI/UL 2034 standard. UL 2075 requires the end-of-life signal be sent to the central panel. What about all the alarms that are in the field with no end of life signal? Some of them have no warning about the CO end of life. For example First Alert’s original CO/smoke combination Model SCO1 gives a 10 year life (the life of the smoke alarm) but the CO sensor has a published 6 year life.  

For about 20 years ANSI/UL 2034 standard did not require any end of life in CO alarms. In fact, for a very long time they did not require and end of life in smoke alarms. I estimated that over 100 million CO alarms and detectors have been sold into the market with NO END-OF-LIFE. This condition is extremely dangerous! People should be warned! I suggest that CPSC, UL and other stakeholders in the industry find a way to warn the American public. This lifetime deficiency has been overlooked for years. Perhaps, a requirement to replace alarms made before 2009 would be one way to do it. If that requirement was introduced in 2014, then most alarms would be replaced that are without an end-of-life. That is step 1; however, not everyone will replace their alarm. Education is necessary to get people to buy a new alarm.

New functional test for system alarms specified in NFPA’s 2012 edition will help get rid of a small percentage of the old alarms. The NFPA standard requires all CO detectors installed after January 1, 2012 be tested with CO upon initial acceptance and thereafter every year by introduction of CO gas into the detector in some fashion, which is left up to the manufacturer to specify.

Life Safety is everyone’s business. Let’s hope no one is injured or worse due to this oversight.