Carbon Monoxide Alarm Quality Problems

In order to understand the “REASONS” for the poor quality of the UL-2034 Listed CO Alarms, you simply need to understand the purpose of, and the wording in, the UL-2034 Standard. The purpose is clearly defined in the “Foreword” of UL-2034.

The total lack of protection from Chronic Low Level CO Poisoning is easy to understand when you consider Item 1.2.1 of the Scope statement of UL-2034:
“Carbon monoxide alarms covered by this standard are not intended to alarm when exposed to long term, low level carbon monoxide exposures or slightly higher short term transient carbon monoxide exposures, possibly caused by air pollution and/or properly installed/maintained fuel-fired appliances and fireplaces. See Table 38.1, Part B, False alarm resistance specifications.”
[ Table 38.1.B indicates the “NO ALARM” or “Ignore” Levels: 30 PPM for 30 days, 60 minutes @ 70 PPM, 10 minutes @ 150 PPM, and 4 minutes @ 400 PPM.]

What is left unsaid in that foreword statement is the extremely wide “time tolerance” permitted between the DO NOT Alarm, and the MUST alarm levels. At 30 PPM, a UL-2034 CO Alarm NEVER has to alarm. [ and none will ] At 70 PPM, it does not HAVE to alarm until 4 HOURS, [240 minutes], of Constant 70 PPM or higher exposure. At 150 PPM, it does not HAVE to alarm until 50 minutes of constant 150 PPM, or higher. At 400 PPM, it does not HAVE to alarm until 15 minutes of 400 PPM, or higher constant exposure.

In my opinion the WORST PART about UL-2034, is that the Standard would “Permit” you and your family to be exposed to 65 to 69 PPM, ….. FOREVER without Alarming.

Add to this the FACT that UL-2034, from the first version released April 30, 1992, to the 1998 version presently being used require NO quality assurance after the “One Time Sample Approval Tests”.

1. No time of manufacture testing is required.
2. No lifetime reliability testing is required.
3. Display accuracy is Plus or Minus 30%, should be 10%.
4. No sensor monitoring is required
5. No “End of Life” warning is required.

After the “Initial” testing of a small group of samples, the Manufacturer is TOTALLY in charge of all testing and quality control. THE FOX IS IN CHARGE OF THE HEN HOUSE  ! ! !

An excellent example of the RESULTS of the badly flawed UL-2034, is the First Alert Model FCD4 CO Alarm. Open the owner’s manual of this UL-2034 Listed CO Alarm to page 19, and you will read, AFTER they establish the required temperature, humidity and air pressure requirements, “Accuracy of digital display”: +100%, ….. -40%.

CO – Experts provides warnings at 10,25,35,50 & 70 PPM, resolution of 1 PPM, hush and automatic hush overrides at all levels, data recall of CO timelines, failsafe design, monitored sensor and end of life warning. All “Error Warnings” are defined on display screen.

IT IS YOUR HEALTH, YOUR LIFE, YOUR CHOICE, ….. CO – Experts advises that you CHOOSE
WISELY. See the following links for:   “The Rest of the STORY”.

1. More details on the “History”, and the causes of the CO Alarm problems from their “Birth” , to today, September 06, 2005. See:

The Chicago Story

Be Aware/Sensor Information

CO Alarm Standards

CSPC Joins the Call


2. What YOU should do for more complete Protection for YOUR Family ? ….. See:
A “Blueprint” for Life-Safety in your HOME



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

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