|
Back to Our
Main Page Carbon monoxide (CO) is a colorless, odorless and tasteless gas that is
poisonous and potentially lethal. CO is a by-product of incomplete
combustion. It is produced |
The Health Effects ofCarbon Monoxide
When we breathe air containing carbon monoxide, it is absorbed through the bloodstream where it displaces oxygen and bonds with the hemoglobin in your blood. Carbon monoxide has a greater affinity to hemoglobin than oxygen; CO bonds to hemoglobin about250 times better than oxygen. Without oxygen, vital organs, your heart and brain become deprived and will begin to deteriorate. To compensate, your heart rate increases, breathing may become difficult and in the most serious circumstances cardiac trauma, brain damage, coma and even death will result.
Symptoms of Carbon Monoxide Poisoning
CO poisoning is difficult to diagnose because its symptoms aresimilar to illnesses such as the flu or the start of a cold.Early warning signs of carbon monoxide poisoning are:
 | headache |
| dizziness |
| nausea |
| fatigue |
If exposure to carbon monoxide continues, symptoms will often become worse and include severe headaches, mental confusion, vomiting, vision and hearing impairment and eventually unconsciousness. When CO poisoning reaches this stage, CO can cause memory loss, permanent brain damage, coma and eventually death.
| Progressive Symptoms of CO Poising - Time VS. Concentration | ||||||
|---|---|---|---|---|---|---|
| The health effects related to CO depend upon its
concentration in the air and the duration of exposure. The amount of
carbon monoxide in the air is measured in parts per million (ppm).
Some examples of the effect of a specific level of carbon monoxide over time are as follows:
|
|
Progressive CO Poisoning
Symptoms - Time vs. Exposure |
|---|
Sources of CarbonMonoxide in the Home
Seven out of eight homes contain some threat of carbon monoxide poisoning. The following is a list of potential sources of carbon monoxide in the home:
 |
 |
 |
 |
 |
 |
 |
 |
 |
Both old and new homes alike contain potential sources of CO. Older homes are susceptible because of malfunctioning appliances and faulty ventilation. However, new homes that are energy-wise and tightly-sealed to trap heat may be at even more risk. Gas, oil and other fuel furnaces, gas-powered appliances, fireplaces and wood stoves all require oxygen to operate efficiently. If the home is too airtight, these devices may begin competing for the available oxygen. They may cause "back drafting" which pulls polluted or CO contaminated air back into the home.
Types of Carbon Monoxide Detection Technology
The three most common CO detection technologies available today are: chem-optical (gel cell), electro-chemical and semiconductor.
1) CHEM-OPTICAL (GEL CELL) TECHNOLOGY
Chem-optical technology alarms are also known as gel cell or biomimetic technology alarms. These alarms utilize a type of sensor that simulates hemoglobin in the blood.
2) ELECTRO-CHEMICAL
Electro-chemical technology alarms are usually battery powered. This type of sensor typically has a limited lifetime of about 2 - 5 years. Some manufacturers' models will require its battery and/or sensor to be changed periodically by installing an expensive replacement. Other manufacturers' models have sealed housing that requires the entire unit to be discarded once the battery power supply is depleted.
3) SEMICONDUCTOR TECHNOLOGY
There are a variety of CO alarms that utilize semiconductor or tin dioxide technology available on the market today. Unlike alarms which utilize chem-optical or electro-chemical technology, semiconductor detectors do not require expensive replacement sensors. However, not all semiconductor CO alarms are alike. Some manufacturers utilize semiconductor sensors that are not designed to be used in a CO specific alarm and may be prone to false and/or nuisance alarms.
NADI is one of the world's largest manufacturers of semiconductor CO alarms. We utilize semiconductor sensors that are designed to detect carbon monoxide. Our alarms are stable and perform well in a multitude of environments. In addition, NADI has developed breakthrough semiconductor technology which consumes even less power resulting in a sensor which allows semiconductor reliability in a battery powered unit--the first of its kind. Only NADI offers a wide range of semiconductor CO alarms with a choice of 120 volt direct plug-in, 120 volt hardwire or battery powered models and a variety of features including low level warning, back-up battery power and digital display.
How NADI Carbon MonoxideAlarms Work
NADI carbon monoxide alarms (under the brand name" American Sensors") sample the air for CO every 1 to 3minutes. When a unit detects a certain pre-programmed level of carbon monoxide, the alarm's microprocessor will store this information and measure the CO level against time. If the CO level is low or is present only for a short time, the alarm will ignore it and burn the sensor clean (so the sensor does not accumulate CO and cause the unit to nuisance alarm). However, if the CO level is high or if a low CO level remains for are-programmed period of time, the alarm will sound an alarm. This programming effectively minimizes the occurrence of nuisance alarms.
All NADI carbon monoxide alarms are Listed by Underwriters Laboratories Inc. UL 2034 and/or Underwriters Laboratories ofCanada.
How to Help Consumers Choose a CO Alarm
The following are considerations consumers should be advised to take when choosing a CO alarm that will be sure to meet their needs.
Carbon monoxide is almost identical in weight to normal air and thus will mix freely with air. For this reason alarms may be installed at any level in a room, from close to the floor level, to the ceiling.
If the CO alarm is to be ceiling mounted, it should be installed away from any existing smoke alarms in order to allow for differentiation between a CO alarm and a smoke alarm in an emergency alarm situation.
| The Consumer Product Safety
Commission recommends that every home be equipped with at least one carbon
monoxide alarm near the sleeping area of the home.
(Because victims of CO poisoning will slip deeper into unconsciousness as
their CO condition worsens, a loud alarm is necessary to wake them). For
maximum protection, place one carbon monoxide alarm on every level of your
home.
|
In homes heated by a boiler system (radiators rather than vents), consumers should consider placing a CO alarm near the furnace room, but about 5 feet away from the furnace itself. Locating a CO alarm directly beside a furnace would be the equivalent of locating a smoke alarm directly above an oven range. Under normal conditions, a furnace will emit very low levels of CO which will quickly dissipate and thus are not dangerous. However a malfunctioning furnace may generate a very high level of CO which a nearby CO alarm will alert you to.
What to do in a CO Alarm Condition
Consumers should consult their owner's manual for a CO alarmprocedure. However, the following is a general procedure:
If a CO alarm sounds a low level warning or hazard levelalarm, consumers should push the test/reset button to silence it.
If no one in the household has any CO symptoms (headache,dizziness, nausea, fatigue) consumers should be advised to openthe doors and windows to air out their house. They should turnoff any gas, oil or other fuel powered appliances including thefurnace and call a qualified technician or their local utility toinspect and repair their home before restarting the furnace andall fuel-burning appliances.
If anyone in the household does have signs of CO poisoning, consumers should leave their home immediately and call their local emergency service or 9-1-1 for help. They should do a headcount to check that all persons are accounted for once outside in the fresh air. They should not re-enter their home until it has-been aired out and the problem corrected by a qualified technician or utility company.
Important Diagnostic Information Regarding CO Alarms
Sometimes after a CO alarm alarms, fire departments, utility companies or HVAC installers have difficulty locating the sourceof CO. This does not necessarily mean that there has been false/nuisance alarm or that the unit is defective. A number of factors may combine to produce CO and these circumstances may have changed by the time the first responder arrives to conduct an inspection.
Air pressure in a house may be influenced by one or any combination of the following: exhaust fans running, gas appliances operating, fireplace burning, wind direction outside the house, exterior vents being temporarily blocked, etc. Ducts may appear to be adequately venting when initially tested. However a certain combination of factors may cause low air pressure in the house which will lead to back drafting of CO through exhaust vents. A thorough test under a variety of conditions may be required in order to locate the source of carbon monoxide.
Every year 1,700 people die from accidental carbon monoxidepoisoning in North America. Over 10,000 others are treated orhospitalized annually. Carbon monoxide is the number one sourceof accidental poisoning deaths.
A 1984 paper by The Mayo Clinic reports that actual COpoisoning figures may be significantly higher than currentstatistics indicate, as reporting and recording procedures forcarbon monoxide incidents are either not efficient ornon-existent. They report that a study done in a south-west U.S.hospital indicated that 20% of patients seeking aid for chronicflu symptoms were found to have elevated levels of carbonmonoxide.
The American Lung Association, The Lung Association (Canada),the Consumer Products Safety Commission, the American MedicalAssociation and the Consumer Health and Safety Coalition have alldeclared carbon monoxide poisoning a primary concern andencourage consumer awareness and education.
North American Detectors Choice of Technology
There are three technologies commonly utilized in residential carbon monoxide alarms. North American Detectors Inc. (NADI) is committed to using those components and technologies which in its opinion are most suitable in each circumstance based on the following criteria:
A proven history of reliability,
Appropriate for the purpose intended,
Recognized by ULC, ULI or BSI as quality components.
Carbon monoxide alarms (CO alarms) currently manufactured by NADI employ semiconductor and biomimetic technology. All Co alarms sold by NADI have been tested by the independent laboratories ULI, ULC and BSI for compliance to relevant standards and carry the mark of the testing laboratory. Every NADI CO alarm is tested with real carbon monoxide gas in an ISO9002 factory before it is sold. NADI’s Quality Assurance group strictly audits the manufacturing process and ULI, ULC andBSI conduct periodic inspections.
Semiconductor Sensors
Semiconductor sensors utilize a controlled quantity of tin dioxide (SnO2) as a sensing element. The sensing material is heated by a small electric heating element and carbon monoxide gas is catalytically broken down at the surface of the sensing element. Electrons are released in this process and reabsorbed by the sensing element. This increase in charged particles lowers the resistance of the sensor.
In an alarm using semiconductor sensors, electronics are used to measure the sensor resistance and from this to calculate the carbon monoxide concentration.
Semiconductor sensors are mechanically simple and are electronic in nature, therefore, they are very long-lived and very reliable. Current designs demonstrate excellent immunity to other gases that may be present.
Millions of semiconductor CO alarms manufactured over the past ten years have provided historical data which demonstrates dependable sensor life of more than ten years.
-more-
Because of this positive history, the results of hundreds of tests by ULC, ULI and BSI over many years, and proven consistency in manufacture, this is the principle technology used by NADI.
The three leading manufacturers in the world use this technology in their most popular models.
Biomimetic Sensors
Biomimetic sensors utilize a material that mimics the response of human hemoglobin to carbon monoxide. In the presence of carbon monoxide gas, the amount of infrared light which will pass-through the sensing material declines. Alarms using this kind of sensor use external circuitry to monitor the transmittance of infrared light through the sensor. The rate of change of the transmittance is used to calculate carbon monoxide gas concentrations. Biomimetic sensors demonstrate acceptable immunity to other gases that may be present. Biomimetic sensors are mechanically simple devices. Alarms using these sensors have field demonstrated dependable sensor life in excess of three years.
Electrochemical Sensors
Electrochemical sensors typically use platinum as a catalyst and acid as an electrolyte to break down carbon monoxide gas and release electrons. The electrons induce a small current which creates a change in potential at external measurement points. Alarms utilizing this type of sensor use external circuitry to monitor the changes in potential and use this information to calculate the concentration of CO gas.
Electrochemical sensors are mechanically much more complex than semiconductor sensors but can provide more accurate measurements of CO concentrations. Modern electrochemical sensors demonstrate good immunity to interfering gases.
Careful design and processing is necessary to ensure accuracy across humidity extremes. Historically, electrochemical sensors have been prone to leakage due to:
Alarms using these sensors have not field demonstrated dependable sensor lifetime in excess of 2 years.
North American Detectors Inc. has designed several carbon monoxide alarms using electrochemical sensors. When NADI dissatisfied that this technology has an acceptable sensor lifetime, we will add electrochemical models to our extensive offering of carbon monoxide alarms.
-more-
Dominant Independent Testing Laboratories
Most retailers in North America and Europe require carbon monoxide alarms to carry the labels of Underwriters Laboratory. (United States), Underwriters Laboratory of Canada (Canada) and the British Standards Institute (Europe).
A brief history of these well-respected independent laboratories are presented below. We have taken this information directly from their web sites:
Underwriters’ Laboratories of Canada (ULC)
A Canadian safety, certification, testing, quality registration, and standards development organization dedicated entirely to the protection of life and property, Underwriters’ Laboratories of Canada (ULC) is anon-for-profit organization headquartered in Scarborough, Ontario, Canada. With modern and fully equipped testing laboratories, it exists for the purpose of investigating devices and materials as to their relation to life, fire or accident hazards, or their value in crime prevention, and to providing authoritative information to inspection authorities.
Underwriters’ Laboratories of Canada (ULC) is accredited by the Standards Council of Canada, under the National Standards System, as a
| Certification Organization |
| Testing Organization |
| Quality Registration Organization (ISO 9000); and |
| Standards Development Organization |
ULC’s listings are accepted across Canada by inspection authorities and others who are concerned with the safety of lifeand property. Products and services which have been certified by ULC are identified by the ULC mark (which consists of ULC in acircle) or by a ULC Certificate.
Underwriters Laboratories Inc. (UL)
Underwriters Laboratories Inc. (UL) is an independent, not-for-profit product safety testing and certification organization. We have tested products for public safety for more than a century. Each year, more than 14 billion UL Marks reapplied to products worldwide.
Since our founding in 1894, we have held the undisputed reputation as the leader in U.S. product safety and certification. Building on our household name in the United States, UL is becoming one of the most recognized, reputable conformity assessment providers in the world. Today, our services extend to helping companies achieve global acceptance, whether itis an electrical device, a programmable system, or company's quality process.
UL has five testing laboratories in the United States and subsidiaries in Mexico, Denmark, England, Italy, India, Singapore, Taiwan, Hong Kong and Japan. We also have numerous international, affiliate and representative offices, as well as field representatives located throughout the world.
Estimated products entering the 14 billion marketplace annually with a UL Mark Types of products evaluated by UL more than 17,000 Manufacturers of products bearing UL more than 40,000 Marks Laboratory and other service locations 43 UL standards for Safety published 726 Square footage of laboratory space more than 1.5 million sq.ft Number of Staff more than 4,000 Inspection centers worldwide 190 Firms registered by UL to ISO more than 3,200 9000, QS-9000 and ISO 14001 Countries in which UL serves clients 89
NADI Community Based Safety Programs
NADI is a company dedicated to making your home and community safer place to live and work. NADI participates in many programs with safety organizations, retailers, fire departments and other safety organizations. Recently NADI developed its interactive Safety House™, a doll house with a resident toy Dalmatian dog Safety™ and educational games included to assist educators and parents in teaching safety to children at avery early age. Another program that NADI is proud to participate in is with the Ontario Fire Marshal’s Public Fire Safety Council. "This council was established in 1993, and is comprised of representatives from the fire service, government, business, industry and the public, all of whom have a profound concern about fire safety. Working on an entirely voluntary basis, the members pool their collective knowledge, expertise and resources to help shape the direction of fire safety strategies in Ontario." To contribute to this program and increase public awareness, several American Sensors™ carbon monoxidealarms display the logo of this council to demonstrate its support of their programs like Learn Not To Burn, The Arson Prevention Program for Children, Alarmed for Life, Risk Watch, Older & Wiser.
All CO alarms sold by North American Detectors Inc. have been tested by the independent laboratories ULI, ULC and BSI for compliance to relevant standards and carry the mark of the testing laboratory. Every NADI CO alarm is tested with real carbon monoxide gas in an ISO 9002 factory before it is sold. NADI’s Quality Assurance group strictly audits the manufacturing process and ULI, ULC and BSI conduct periodic inspections.
American Sensors™ carbon monoxide alarms manufactured by NADI are sold by leading home and hardware retailers throughout Canada and the U.S.A.
North American Detectors Inc. is a leader dedicated to there search, development, and distribution of a full-line of carbon monoxide alarms, smoke alarms, explosive gas detectors, and other Home Health and Safety products.
NADI currently has 28,883,155 common shares issued and outstanding. Common shares trade on the CDN Over The Counter Exchange under the symbol NADI. For more information please contact Michele Hughes, Director Investor and Corporate Relations, (416) 496-5966.
Back to top Back to Main Page
