Carbon Monoxide Gas Alarm Causes
Why does the CO alarm keep going off? InspectAPedia® -
What makes a CO alarm or carbon monoxide detector go off?
How to inspect buildings where carbon monoxide gas is suspected
Testing for Carbon Monoxide presence in buildings
Medical effects of carbon monoxide exposure - CO exposure - Toxicity of carbon monoxide gas
Carbon monoxide gas exposure limits & Symptoms of carbon monoxide poisoning
Recommendations for gas measurement instruments, gas detector tubes, Draeger & Gastec tubes & pumps for detection of gases
Questions & answers about the behavior of CO detectors: what sets off carbon monoxide detectors, and is it always CO?
This document discusses the causes of CO alarms going off - when a carbon monoxide alarm sounds you should assume there is dangerous carbon monoxide gas (CO) present. But other things might set off some alarm and not all of them are CO hazards.
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We give references and explanation regarding Toxicity of Carbon Monoxide, based on literature search and search on Compuserve's Safety Forum. This is background information, obtained from expert sources. This
text may assist readers in understanding these topics. However it should by no means be considered complete nor authoritative.
Seek prompt advice from your doctor or health/safety experts if you have any reason to be concerned about
exposure to toxic gases. Carbon monoxide poisoning can be fatal but exposure at lower limits can produce flu-like symptoms
and headaches that are often mistaken for ordinary illness. Readers of this document should also see HEAT EXCHANGER LEAKS.
IF YOU SUSPECT CARBON MONOXIDE POISONING GO INTO FRESH AIR IMMEDIATELY
and get others out of the building, then call your fire department or emergency services for help.
Links on this page also direct the reader to carbon dioxide gas information in a separate document.
Carbon monoxide detector alarms may sound for a variety of reasons, but until you have diagnosed for sure why a particular alarm has sounded, you should assume that it has detected dangerous carbon monoxide indoors and you should follow our safety advice above.
Beware that the production of dangerous carbon monoxide gas in a building is usually not constant - it can start and stop. So even if someone tests and does not find CO gas present, especially if your CO alarm has been sounding, you can NOT assume that conditions are safe in the building, and further expert visual inspection of heating equipment, chimneys, etc. are in order.
For example, simply closing the door to a boiler room where gas fired equipment is operating can cause sudden production of CO gas if there is insufficient combustion air when the door is closed. Yet when someone opens the door to inspect the area, more combustion air is provided. CO production may stop. Also see INSPECTION for CARBON MONOXIDE and see TESTS for CARBON MONOXIDE.
Here are some causes of Carbon Monoxide Detector alarms sounding:
The CO alarm has detected carbon monoxide in the building at a dangerous level. The alarm may sound if there is a sudden surge of high concentrations of CO or it may sound if lower levels of CO have been present for a longer period.
Heating system malfunctions or malfunction in other gas or oil burning equipment (such as a space heater or a water heater) can produce dangerous levels of carbon monoxide indoors
A blocked chimney flue can cause dangerous backup of carbon monoxide gas indoors
Inadequate combustion air can cause production of dangerous levels of CO indoors
Other indoor contaminants, including smoke, other particles, chemicals, and gases might cause some models of smoke alarms or carbon monoxide detector alarms to sound.
Beeping or chirping from a CO carbon monoxide detector alarm, a sound that is not continuous but sounds every few minutes, may indicate a dead or dying battery - replace the battery; if the alarm is in doubtful condition replace it.
Safety Suggestions: Install Carbon Monoxide Detectors in addition to Smoke Detectors
Carbon monoxide detectors are inexpensive and readily available, both as a battery-operated
unit and as a unit that plugs into an electrical outlet in the home.
No home should be without this safety protection,
and homes with gas-fired equipment (natural gas or LP propane), space heaters, or other sources of risk should be
extra cautious. Smoke detectors do not protect against carbon monoxide poisoning, and the opposite is also true. Carbon
monoxide detectors do not warn of smoke or fire
Questions & Answers regarding this article
Questions & answers about the behavior of CO detectors: what sets off carbon monoxide detectors, and is it always CO?
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A Toxic Gas Testing Plan: A Gas Sampling Plan for Residential and Commercial buildings lists some of the toxic indoor gases for which we test, depending on the building complaint and building conditions
Gas Exposure Hazard Levels: for Toxic Gas Exposure to Ammonia, Arsine, Arsenic, Bromine, Carbon Dioxide, Carbon Monoxide, Hydride, Ozone - allowable exposure levels and hazard levels
Formaldehyde: US EPA. UFFI (Urea Formaldehyde Foam Insulation) was previously considered a hazard (formaldehyde outgassing).
Subsequent research virtually closed concern regarding this material; however formaldehyde appears to remain a health concern for sensitive individuals.
Ozone Warnings - Use of Ozone as a "mold" remedy is ineffective and may be dangerous.
Sampling for gases in air such as VOC's, MVOC's, toxic chemicals, and combustion products.
Unfortunately no single test or tool can detect all possible building contaminants. We use methods and equipment which can test for common contaminants. If the identity of a specific contaminant is known in advance we can also test for a very large number of specific contaminant gases in buildings.
We use gas sampling equipment provided by the two most reliable companies in the world, Draeger-Safety's detector-tubes and Drager accuro� bellows pump, the Gastec� cylinder pump and detector-tube system produced by Gastec or Sensidyne, and we also use Sensidyne's Gilian air pump. For broad screening for combustibles and a number of other
toxic gases and for leak tracing we also use Amprobe's Tif8850. All of these instruments, their applications, and sensitivities (minimum detectable limits) for specific
gases are described in our Gas Sampling Plan online document.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
Air Pollution Toxicology: APTI Course SI:300, Introduction to Air Pollution Toxicology, US EPA Air Pollution Training Institute, Environmental Research Center, Research Triangle Park, NC 27711, Sept. 1993, web search 08/28/2010, original source: http://yosemite.epa.gov/
A Toxic Gas Testing Plan: A Gas Sampling Plan for Residential and Commercial buildings lists some of the toxic indoor gases for which we test, depending on the building complaint and building conditions
CCSP, 2008: Analyses of the effects of global change on human health and welfare and human systems. A Report by the U.S.
Climate Change Science Program and the Subcommittee on Global Change Research. [Gamble, J.L. (ed.), K.L. Ebi, F.G. Sussman,
T.J. Wilbanks, (Authors)]. U.S. Environmental Protection Agency, Washington, DC, USA. Web search 08/28/2010, original source: http://nepis.epa.gov/
Gas Exposure Hazard Levels: for Toxic Gas Exposure to Ammonia, Arsine, Arsenic, Bromine, Carbon Dioxide, Carbon Monoxide, Hydride, Ozone - allowable exposure levels and hazard levels
Health Effects of Carbon Dioxide - see "National Advisory Committee for Acute Exposure Guideline Levels (AEGLs) for Hazardous Substances; Proposed AEGL Values, Federal Register Document", http://www.epa.gov/EPA-TOX/2002/February/Day-15/t3774.htm note that these are proposed guidelines
GTSP, 2006: Carbon Dioxide Capture and Geologic Storage: A Core Element of a A Global Energy Technology Strategy to Address Climate Change (PDF, 37 pp., 6.05 MB, About PDF). April 2006, JJ Dooley et al. Global Energy Technology Strategy Program (GSTP)
IPCC, 2005: Special Report on Carbon Dioxide Capture and Storage, Special Report of the Intergovernmental Panel on Climate Change [Metz, Bert, Davidson, Ogunlade, de Coninck, Heleen, Loos, Manuela, and Meyer, Leo (Eds.)]. Cambridge University Press, The Edinburgh Building Shaftesbury Road, Cambridge CB2 2RU England
Fluorine, Its Compounds, and Air Pollution,: a Bibliography with Abstracts, US Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, North Carolina 27711, December 1976. Web search 08/28/2010, original source: http://nepis.epa.gov. NOTE: because the EPA's original source of this document in PDF format is damaged we have created a text image file, converted to a new PDF for readability.
Formaldehyde: US EPA. UFFI (Urea Formaldehyde Foam Insulation) was previously considered a hazard (formaldehyde outgassing). Subsequent research virtually closed concern regarding this material; however formaldehyde appears to remain a health concern for sensitive individuals.
Nitrogen Oxides: Air Quality Criteria for Oxides of Nitrogen, Vol III of III, US EPA, EPA600/8-91/049cF, August 1993, web search 08/28/2010, original source: http://nepis.epa.gov [Large PDF 25MB] Key chapters in this document evaluate the latest scientific data on (a) health effects of NOx measured ill laboratory animals and exposed human populatIOns and (b) effects of NOx on agricultural crops, forests, and ecosystems, as well as (c) NOx effects on visibility and nonbiological materials. Other chapters describe the nature, sources, distribution, measurement, and concentratiOns of NOx m the environment These chapters were prepared and peer reviwed by experts from various state and Federal government offices, academia, and private industry for use by EPA to support decision makIng regarding potentIal risks to public health and the enVIronment Although the document IS not intended to be an exhaustIve literature reVIew, It IS intended to cover all the pertinent literature through early 1993
Ozone Warnings - Use of Ozone as a "mold" remedy is ineffective and may be dangerous.
Sampling for gases in air such as VOC's, MVOC's, toxic chemicals, and combustion products.
Unfortunately no single test or tool can detect all possible building contaminants. We use methods and equipment which can test for common contaminants. If the identity of a specific contaminant is known in advance we can also test for a very large number of specific contaminant gases in buildings.
We use gas sampling equipment provided by the two most reliable companies in the world, Draeger-Safety's detector-tubes and Drager accuro� bellows pump, the Gastec� cylinder pump and detector-tube system produced by Gastec or Sensidyne, and
we also use Sensidyne's Gilian air pump. For broad screening for combustibles and a number of other
toxic gases and for leak tracing we also use Amprobe's Tif8850. All of these instruments, their applications, and sensitivities (minimum detectable limits) for specific gases are described in our Gas Sampling Plan online document.
Radon Gas U.S. EPA Radon level maps, web search 2005, original source: http://www.epa.gov/iaq/radon/zonemap/zmapp33.htm
"Table Z-1 Limits for Air Contaminants, 1910.1000 Table Z-1" OSHA standard for air contaminant limits (http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9992) - includes for CO2, Carbon dioxide.........| CAS No. 124-38-9 | 5000 ppm | 9000 mg/m3 limits for carbon dioxide as an air contaminant.
GASES, EXPOSURE, TESTING Toxic Gas Exposure Hazards and Test Protocols including links
to our toxic gas exposure screening and gas testing protocols.
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Use of Ozone as a "mold" remedy is ineffective and may be dangerous.