GRI study done by Paul Clifford

Evaluating the Performance of Residential CO Alarms.
June 2002

Document Type: Report
Report Type: Final Report
Report Period: 2/99 – 12/01
Authors: Clifford, Paul K.
Corporate Source: Mosaic Industries, Inc., Newark, CA
Sponsor: GRI, Des Plaines, IL
Pagination: 172p
GTI Contract Number: 2309
Project Manager: Srivastava, Vipul
Sector: Residential & Commercial

This study assessed the performance of commercially available carbon monoxide (CO) alarms, several preproduction prototypes, and several alarms removed from residences by first responders. Alarm performance was assessed in terms of the Underwriters Laboratories UL 2034 design specification for sensitivity to CO, immunity to interfering gases, accuracy of digital displays, and ability to detect CO in ambient air of varied relative humidity. Findings parallel the results of earlier studies, indicating that the poor performance of commercial CO alarms has not significantly improved. These tests reveal that a significant portion of some widely installed alarm brands did not alarm in CO poisoning incidents with potentially lethal consequences. In particular, they did not adequately protect at low relative humidity. Digital display readings on some alarms showed little relationship to actual CO levels. Results indicate that certification to UL 2034 does not assure the performance or reliability of CO alarms. The study sheds light on the physical and algorithmic determinants of the poor performance of CO alarms, and proposes solutions for some of their most serious technical deficiencies. It is recommended that reliability standards, including specifications for alarm longevity and time-of-manufacture testing, as previously recommended by the Consumer Product Safety Commission (CPSC) and GRI, be incorporated in the UL 2034 standard. Gas utilities, appliance manufacturers and others are urged to require certification to the Canadian Standards Association CSA 6.19-01 standard, which includes improved reliability specifications.

Availability Note:
Full report is available online (pdf 1.2 MB).


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CO Experts
19299 Katrina Lane – Eldridge Missouri 65463-9102
Tel: 1-888-443-5377 Fax: 1-888-436-5377