Standard - Occupant Interview

An interview with the building occupant(s) is an essential component of all CO testing. The occupants may describe when they have problems and/or what they think might be causing it. A history of health symptoms and possible CO occurrences may help to pinpoint any potential problems. CO Analysts shall conduct an occupant interview as a part of every inspection.

Best Practices - Client Interview

Perform interview in an area safe from CO exposure.
Inquire about health problems.
Question occupants to see if they have experienced any specific CO poisoning symptoms including: headaches, dizziness, nausea, confusion, rapid breathing, fatigue, unconsciousness, disorientation, or flue like symptoms.
Ask if anyone else has shown signs of experiencing these symptoms.
If anyone appears to be experiencing symptoms, refer them to medical evaluation (see action levels).
Ask about unusual moisture problems.
Ask about recent mechanical problems.
Ask if a vehicle has been in or out of the garage recently (if applicable).
Ask if oven or range was in use. Ask if the fireplace was in use (if applicable).
Ask if vent fans were in use.
Repeat customer health inquiries if a serious CO problem is found and the occupants have not acknowledged any symptoms previously.
Reference action levels.

Standard - Building Inspection

A walk through inspection of the structure is necessary to ensure no potential source of CO production is missed. Utilize a standardized recording form to ensure no potential source is missed and document all findings for future reference.

Best Practices - CO Recording Form

Use a standardized CO recording form when performing a CO inspection. Include:
   Company, technician, date and time of testing.
   Client and physical location.
   Interview information including health symptoms.
   Smokers in the structure.
   Is this an emergency situation or routine procedure - inspection classification.
   Listing of normal CO sources to be inspected and results from testing those sources.
   Location of all Combustion Appliance Zones.
   Mechanical and passive ventilation within the structure.
   Type of fuels in use.
   Location and numbers of smoke and CO detectors.
   Make, model numbers and type of detectors.
   Attached or detached garage.
   Potential exterior sources of CO production.
   Type, model and serial numbers of combustion appliances.
   Vent system condition for each appliance (if vented).
   Weather conditions of the day.
   Action taken.
   Follow-up

Best Practices - Building Walk Through Inspection

Record all testing information.
Continually test for ambient CO levels while inspecting each zone.
Note any CO readings in attached garages.
Inspect for and record any CO sources near exterior (busy street, grills, go-carts, shop with gasoline, power equipment, etc.)
Identify and inspect each Combustion Appliance Zone (CAZ) within the building recording number and type of combustion appliances.
Inspect for and record in each CAZ: the number, type and location of exhaust appliances (bathroom vent fans, dryers).

Standard - CO Detectors

Upon completion of a CO analysis, check all CO detectors to ensure proper maintenance and operation.
Analysts should recommend CO detector installation in all CAZ's. Detectors that provide warnings between 35 - 99 ppm are recommended - especially if small children, elderly or persons with health problems occupy the building. Detectors that maintain operation during power outages ( battery powered or battery back-up) provide additional safety. Detectors should have the capability of being mounted at eye level or higher. Digital detectors can provide the earliest warning, but only when visually observed. Detectors should meet current standards, UL2034 or IAS 6-96 (subject to change). Installing digital detectors in working areas where they can be easily observed is an excellent protection strategy.

Best Practices - CO Detectors

Follow detector manufacturer's recommendations for installation and maintenance.
If only one detector is installed, it should be mounted high in an area of good airflow.
Install CO detectors in all combustion appliance zones (CAZs)
Areas containing unvented combustion appliances should have a digital CO detector.

Standard - Client Education

CO Analysts shall work with the occupants requesting the analysis to inform them about: the test results on their structure, potential sources of CO, causes of CO production, how to minimize risk of CO poisoning, proper maintenance of HVAC equipment and detector placement/maintenance.

Best Practices - Client Education

Thoroughly review the results of the CO analysis with the customer. Explain to them you are going to discuss sources of CO, causes for its production and then develop a protection strategy. Discuss with the customer all potential sources of CO production. Include the following: outside sources such as roads; automobiles in attached garages; other gasoline powered equipment such as generators; indoor combustion appliances such as heating systems, DHW heaters, kitchen ranges; gas or wood fired fireplaces; self cleaning ovens; and unvented space heaters. Inform the occupants about the causes of CO production. Include: normal by-product from internal combustion engines, incomplete combustion, insufficient air, lack of maintenance, improper equipment set-up and impingement restricting the combustion process.
Discuss strategies to minimize risk of CO build-up. Include: never warming up car in garage, providing ventilation where fireplaces/unvented space heaters are in use, vent use for kitchen range and annual servicing of combustion appliances by trained professionals knowledgeable in the use of CO testing equipment.
Develop in conjunction with the customer a protection strategy which shall include: maintenance schedules for appliances including occupant performed tasks such as filter changing, adequate CO detector coverage and maintenance of detectors, operation of ventilation systems, and use/operation of fireplaces/unvented space heaters.

Good sources of information about control methods are as follows:

1. ACGIH [1992]. Industrial ventilation--a manual of recommended practice. 21(st) ed.
Cincinnati, OH: American Conference of Governmental Industrial Hygienists.

2. Burton DJ [1986]. Industrial ventilation--a self study companion. Cincinnati, OH:
American Conference of Governmental Industrial Hygienists.

3. Alden JL, Kane JM [1982]. Design of industrial ventilation systems. New York, NY:
Industrial Press, Inc.

4. Wadden RA, Scheff PA [1987]. Engineering design for control of workplace hazards.
New York, NY: McGraw-Hill.

5. Plog BA [1988]. Fundamentals of industrial hygiene. Chicago, IL: National Safety
Council.

What are the different types of carbon monoxide detectors and how do they
work?

There are a number of different types and brands of carbon monoxide detectors on the market today; They can be most easily characterized by whether they operate on current or batteries. Underlying this, in most cases, is the type of sensor employed in the detectors operation. Detectors using current typically employ some type of solid-state sensor which purges itself and resamples for CO on a periodic basis. This cycling of the sensor is the source of its increased power demands. Detectors powered by batteries typically use a passive sensor technology which reacts to the prolonged exposure to carbon monoxide gas.

Are some types of detectors better than others? How do I select the best detector for me?

Regardless of the type of sensor used all detectors sold on the market today should conform to minimum sensitivity and alarm characteristics. These characteristics have been defined and are verified by Underwriters Laboratory in their standard for carbon monoxide detectors UL 2034. This standard was most recently revised in June of 1995 and went into effect in October of 1995. This revision specified additional requirements regarding identification of detector type, low-level (nuisance) alarm sensitivity and alarm silencing. Under no circumstances should one purchase a detector that is not UL listed.

Each of the two types of detectors mentioned previously has advantages and disadvantages. The proper detector for each application or installation should be chosen based on the application requirements and the products specifications. The following are the principle advantages and disadvantages of the two different type detectors:

Characteristic                                 Current                  Battery Operated

        Cost                                          $30-50                          $30-50

Ease of Installation               More difficult- requires        Less difficult. Can be
                                           outlet near detector or         placed anywhere needed.
                                           'hard wiring'.

Maintenance                        No maintenance required   Requires periodic
                                           during life of product          replacement of
                                           (5-10 years).                     Detector battery/sensor module
                                           sensor becomes more        every 2-3 years at a
                                           sensitive with age.              cost of ~$20.

Reaction Time/Exposure      Gives continuous display    Reaction time depends
Level Display                       of CO levels updated        on concentration level
                                           every few minutes.             and duration of exposure. Display information is limited.

Reset Time                          Will reset immediately        Reset time depends on
                                           once CO problem is          exposure concentration
                                           corrected.                         and duration. May
                                                                                    require removal of
                                                                                    sensor pack. A silence
                                                                                    button, however, is now
                                                                                    provided/required.

Where can I get further information concerning carbon monoxide
detectors?

Several manufacturers of carbon monoxide detectors offer toll free numbers for additional information regarding their products.
These numbers are as follows:

Manufacturer Number

American Sensors 800-387-4219

Enzone 800-448-0535

First Alert 800-323-9005

Jameson 800-779-1719

Nighthawk 800-880-6788

Quantum 800-432-5599

Radio Shack Contact your local store

S-Tech 800-643-5377

Additional information with product ratings is contained in the July 1995 Consumer Reports issue on home safety products.
One word of note regarding the ratings in this issue- the products tested have probably since be replaced by updated models conforming to the revised UL 2034 standard which took effect in October 1995. Check with the manufacturer for current information.

Grainger is probably the best provider of CO detectors in the Daytona area.