CO Measurement Protocols

DONNAY ENVIRONMENTAL HEALTH ENGINEERING 10145 Falls Rd, Lutherville MD 21093-3622, [email protected], 410-889-6666, fax 889-4944

Protocols for Measuring Carbon Monoxide Indoors, in Breath and in Vehicles

© A P R I L 2 0 0 3 , A L B E R T D O N N AYL A S T R E V I S E D A P R I L 2 0 0 7

mailto:[email protected]

D O N N A Y E N V I R O N M E N T A L H E A L T H E N G I N E E R I N G10145 Falls Rd, Lutherville MD 21093-3622, [email protected], 410-889-6666 fax 889-4944

DEADLY WARNING

BREATHING H IGH LEVELS OF CO FOR EVEN SHORT PERIODS OF T IME MAY CAUSE CHRONIC ILLNESS OR DEATH. PREGNANT WOMEN,

CHILDREN, THE ELDERLY AND PEOPLE WITH ANY CHRONIC ILLNESS ARE AT GREATER R ISK FROM CO THAN HEALTHY ADULTS. FOR YOUR

PROTECTION, NEVER DEL IBERATELY INHALE CARBON MONOXIDE (CO) AT ANY LEVEL FROM ANY SOURCE AND, AS THE US NAT IONAL INST ITUTE

FOR OCCUPATIONAL HEALTH AND SAFETY RECOMMENDS, IMMEDIATELY EVACUATE ANY AREA IN WHICH CO LEVELS EXCEED 200 PPM.

IF EXPERIENCING CO SYMPTOMS , SEEK FRESH A IR IMMEDIATELY AND, IF SYMPTOMS PRESIST , CALL 911 AND SEEK SUPPLEMENTAL OXYGEN FROM

A PHYSIC IAN.

ACKNOWLEDGEMENTS

THANKS TO R ICK KARG FOR SHARING H IS EXTENSIVE EXPERIENCE TEST ING VARIOUS CO SOURCES AND H IS MANY SUGGESTIONS FOR

IMPROVING THE INDOOR CO PROTOCOL. THANKS ALSO TO GABE DONNAY FOR GREATLY IMPROVING THE GRAMMAR AND VOCABULARY.

ALBERT DONNAY RETAINS SOLE RESPONSIB IL ITY FOR THE F INAL TEXT.

DISCLAIMERS

ALBERT DONNAY AND DONNAY ENVIRONMENTAL HEALTH ENGINEERING D ISCLAIM ANY RESPONSIB IL ITY OR L IAB IL ITY FOR ANY HARM OR LOSS THAT MAY BEFALL ANYONE AS A RESULT OF US ING (OR MISUSING) ANY OF THESE PROTOCOLS. THE PROTOCOLS ARE WRITTEN FOR MEDICAL ,

PUBL IC HEALTH, HOME INSPECTION PROFESSIONALS TO USE WITH ELECTRO-CHEMICAL CARBON MONOXIDE DETECTORS THAT CAN BE AND

HAVE BEEN ACCURATELY CAL IBRATED . CO DETECTORS THAT CANNOT BE CAL IBRATED (SUCH AS D IG ITAL HOME CO ALARMS) MAY BE USED WITH

THESE PROTOCOLS, BUT BEFORE USING THEM , THEY SHOULD BE CHECKED AGAINST CAL IBRATED DETECTORS TO BE SURE THAT THEY

ARE SUFF IC IENTLY ACCURATE.

ã Copyright 2003, Albert Donnay Questions ? Comments ? Corrections ?

Email [email protected] or Call 410-889-6666

PROTOCOLS FOR MEASURINGCARBON MONOXIDE (CO)

mailto:[email protected]


INDOORS, IN BREATH AND IN VEHICLES

Table of Contents

D O N N A Y E N V I R O N M E N T A L H E A L T H E N G I N E E R I N G

10145 Falls Rd, Lutherville MD 21093-3622, [email protected], 410-889-6666 fax 889-4944

1 : C O D E T E C T O R S

1.1: Recommended CO Detectors 1

1.2: Calibrating CO Detectors 2

1.3: Caring for CO Detectors 2

2 : C O I N D O O R S

2.1: Before Measuring CO Indoors 3

2.2: Measuring Ambient CO Indoors 3

2.3: Measuring CO Sources Indoors 4

2.4: Recording Levels of CO Measured Indoors 5

2.5: Tips for Reducing CO Indoors 6

3 : C O I N B R E A T H

3.1: Before Measuring CO in Breath 7

3.2: Measuring CO in Breath 8

3.3: Recording Levels of CO in Breath 9

3.4: Tips for Reducing CO in Breath 10

4 : C O I N V E H I C L E S

4.1: Before Measuring CO in Vehicle 11

4.2: Measuring CO in Vehicles 11

4.3: Recording CO Levels Measured in Vehicles 13

4.4: Tips for Reducing CO in Vehicles 14

APPENDIX A :

CO LEVELS OF CONCERN 15

APPENDIX B :

REFERENCES ON CO MEASUREMENT 16

D O N N A Y E N V I R O N M E N T A L H E A L T H E N G I N E E R I N G 10145 Falls Rd, Lutherville MD 21093-3622, [email protected], 410-889-6666 fax 889-4944

1

D O N N A Y E N V I R O N M E N T A L H E A L T H E N G I N E E R I N G508 Westgate Road, Baltimore MD 21229, [email protected], 410-566-3333, fax 362-6401

1 Carbon Monoxide Detectors Human understanding of any physical thing is bounded both by the limits of our senses to perceive the thing and by the limits of our instruments to measure it.

1.1 Recommended CO Detectors

To measure CO indoors, in breath and in vehicles with sufficient accuracy for medical and legal purposes, Donnay Environmental Health Engineering (DEHE) recommends using CO detectors with an electrochemical sensor and a digital display (from zero to at least 999 ppm) that can be calibrated by exposing it to CO of a known concentration (usually via a small tank). There are several portable CO detectors (under $500) that can be calibrated (with kits costing under $50), some of which also provide instant alarm(s) above various CO levels. All are lightweight, battery operated and small enough to fit in a pocket.

The CO detectors recommended and sold by DEHE are listed in Table 1 and 2 below (call 410-889-6666 for current pricing). All have digital displays from 0ppm and replaceable sensors that can be calibrated by the user. Detectors capable of datalogging CO levels over time (from days to months, depending on the sampling interval you select) are not necessary for measuring CO levels in breath (Chapter 3), but they are very useful and recommended for measuring CO levels over time indoors (Chapter 2) and in vehicles (Chapter 4).

DEHE does not recommend using CO detectors with metal oxide or biomimetic sensors for measuring CO levels indoors, in breath or in vehicles as they are less accurate than electrochemical sensors. DEHE also does not recommend using UL- or CSA-listed residential “CO alarms,” although most are under $40, because none can be calibrated, only some are portable and all are prohibited both from displaying CO levels below 30ppm and alarming in response to CO levels under 70ppm. A low-level “CO monitor” is available from CO-Experts (800-643-5377) for under $150 that displays CO from 10ppm to 70ppm and provides an instant warning above 25ppm, but it too cannot be calibrated. If these devices are used for medical or legal purposes, their accuracy should be checked before each use as described below (see Section 1.2).

Table 1Recommended Calibrateable CO Detectors (<$400)

2


ToxiRae II, 3.6” x 1.9” x 0.9”, weight = 3.6 oz, display = 0-1999 ppm

Bacharach Snifit 50, 5.5” x 2” x 1.6, weight = 8 oz, display = 0-1999 ppmBW Gas Alert, 1.1” x 2” x 3.8”, weight = 2.9 oz, display = 0-999 ppmFluke CO 220, 6.8” x 2” x 1.5”, weight = 4.0 oz, display = 0-999 ppmScientific Instruments T40, 3.4” x 2.3” x .8”, weight = 3.5 oz, display = 0-999

Table 2Recommended Calibrateable CO Dataloggers (<$700)Scientific Instruments T82, 4.1” x 2.7” x 1.2”, weight = 7oz, display =0-1500

Zellweger Impulse Pro, 4.8” x 2.5” x 1.2”, weight = 4.3oz, display = 0-1500Drager Pac7000, 2.5" x 3.3" x 0.8"”, weight = 3.8oz, display = 0-1999

1.2 Calibrating CO Detectors

CO detectors should be tested and calibrated according to the manufacturer’s instructions before each use but at least once a month, even though (if well cared for) most models only need adjustment every few months or years. Always start by calibrating CO detectors in clean air (to set an accurate zero), before exposing them (via a “hood” or hose) to a known concentration of CO (usually from a small tank containing 35 or 100ppm). Electrochemical CO sensors gradually “drift” and eventually (after 2 to 4 years) fall so far out of range that they can no longer be calibrated accurately and must be replaced.

To test the calibration of CO detectors that cannot themselves be calibrated (such as Home CO Alarms), put them in a clear plastic bag with an accurately calibrated detector and then add smoke from a cigarette or an incense stick before sealing (or twisting) the bag so that the smoke cannot escape. Wait until the CO readings stabilize (should be within 2 minutes) and then calculate the percent difference (D) between the CO level shown on the uncalibrated detectors (X) and that on the calibrated detector (Y). D = (Y-X) divided by X. For example, if X = 90ppm and Y = 100ppm, then the percent difference D = (100-90) / 90 = 10 / 90 = +0.11. Therefore, to correct the readings of this uncalibrated detector, the readings should be increased by 11%. Keep a written log of calibration dates and readings for all findings all for CO detectors.

1.3 Caring for CO Detectors

Electrochemical CO detectors should never be exposed to extreme cold or heat for long periods (a few hours at most) as temperatures under 32F will freeze the sensor while over 100F will quickly and irreversibly dry out the sensor. CO detectors also should never be directly exposed to water or sprays or mists of any other fluids.

3


2 Carbon Monoxide Indoors Humans have been making fires –and carbon monoxide--inside their homes for at least 400,000 years. While Neanderthals usually kept just one open fire burning in their caves, many Americans today live in homes with dozens of open gas flames, each one a potential source of CO poisoning.

2.1 Before Measuring CO Indoors

The ambient level of CO indoors is never lower than the ambient level of CO outdoors (away from sources such as smoke stacks and automobiles). Therefore before measuring CO indoors, you should measure the CO level outdoors (at eye level) just before you go inside, and then subtract this outdoor level (usually 0) from whatever levels you measure indoors. Note that among home CO alarms, only the Senco Model One can display continuously from zero ppm (for up 2 hours). When other brands display zero, the actual level may be anywhere from 0-29 ppm (or Nighthawk in test mode, from 0-10ppm).

2.2 Measuring Ambient CO Indoors

The ambient level of CO measured indoors varies depending on the detector’s proximity to active CO sources such as ovens or water heaters and the dilution of these sources by both passive and active air intake and exhaust ventilation. Before measuring any specific CO sources, you should walk slowly though the building (at least all floors and all rooms if possible) while watching your CO detector to see if it displays any CO levels greater than whatever level you measured outdoors just before entering. If measuring CO for medical or legal purposes, you should record the CO level measured outside and then in each room or floor that you inspect (a sample recording form is provided in section 2.4, below).

If you are using a CO datalogger to monitor ambient CO levels over time—which is highly recommended--you should install it at eye level or higher and no closer to any suspected CO source than 5 feet. Since CO levels can vary quickly and greatly over time depending on many factors, CO dataloggers should be left in place for as long as possible (at least a few days to a few weeks), while the datalogging interval should be set as short as possible (no more than a few minutes).

E2.3 Measuring CO Sources Indoors

Even if ambient CO levels indoors are found to be no greater than ambient CO outdoors during the initial walkthrough (see above), each potential source of CO indoors should be

4


still tested separately for 10 minutes each (with all windows and doors in the house closed and all fans off) to be sure that its operation does not result in the accumulation of significant CO levels (see Appendix A). If testing any of the appliances listed below causes any increase in the ambient CO level indoors (as measured in the center of the room), be sure to reopen windows after the test until the CO level in the room falls to the same level as outdoors.

To test unvented CO sources such as ovens, ranges, space heaters, and vent-free gas fireplaces, turn off and wait until they are cold to the touch. Hold your CO detector about two feet above the source with the sensor aperture facing down and then turn the appliance on to its maximum level. While holding the detector as described (see sample reporting form on next page for more details), watch it closely to note the highest CO level measured in the first five minutes. Then move to the center of the room and, holding the detector at eye level, watch it closely for another five minutes and record the highest level of CO measured there. If over 100 ppm, shut off the appliance immediately and evacuate.

To test vented CO sources such as water heaters, boilers, furnaces, and chimneys, hold your CO detector about two feet from the lowest opening or “collar” in the flue (if there is one) or two feet above the combustion chamber (if there is no opening in the flue). Then start the appliance. As with unvented appliances, record the highest CO level measured in the first five minutes while standing next to the source. Then move as close as possible to the center of the room and record the highest CO level measured in the next five minutes. (To start a water heater, open any hot water tap. To start a furnace or boiler, turn the thermostat up to its maximum temperature.)

To test attached garages (only recommended if used to store motor vehicles), open the garage door when the vehicle is inside and cold and ask the driver to start the vehicle while you stand at the front of the car. (Keep the door to the house closed.) The driver should let the vehicle warm up as long as they normally do and then drive out, shutting the door behind them (again, as they normally do). As with most other appliances, you should not need to wait more than ten minutes after the vehicle leaves to measure the maximum CO level in the middle of the garage. Always warn home occupant(s) that most of the CO left in an attached garage after the vehicle leaves and the door is closed will drift into the house, causing a gradual rise in ambient CO levels in other rooms that usually takes several hours to peak, and several more hours to return to the prior (ambient) level. This is best measured by leaving one CO datalogger in the garage and another in the house, either in the bedroom above (if any) or in whatever room is adjacent (if none is above).

2.3 Recording Levels of CO Indoors

People conducting CO inspections professionally (whether indoors, in breath and/or in vehicles) should give their clients a written copy of their inspection results and keep a written copy for their own records. See next page for a sample form.

5


CARBON MONOXIDE LEVELS MEASURED INDOORS

DATE ____________ TIME __________ AMBIENT CO OUTDOORS = _________PPM

LOCATION _________________________________________________________

MEASURED BY _____________________________________________________

DETECTOR ID # ____ DATE OF LAST CALIBRATION ____________ @ ______ PPM

LEVELS OF AMBIENT CO INDOORS (from initial walkthrough, minimum 5 minutes/floor):

BASEMENT=____________PPM 1ST FLOOR=____________PPM

2ND FLOOR =____________PPM 3RD FLOOR=___________ PPM

ROOMS WITH HIGHER CO LEVELS: _____________________________________ = ___________PPM

_____________________________________ = ___________PPM

LEVELS OF CO FROM SPECIFIC SOURCES Hold CO detector near source as described below for 5 minutes, then move to center of room for 5 minutes more. Shut off the source immediately and evacuate if room CO goes over 100 ppm; ventilate when done until room CO goes below 9.

Max ppm in 0-5 minutes (while standing next to CO source, minus outdoor level)

Max ppm in 5-10 minutes (eye level while at center of room, minus outdoor level)

FURNACE, 2’ to side of flue collar or fire box GAS WATER HEATER, 2’ to side of flue collarGAS SPACE HEATER, 2’ above & in frontGAS OR WOOD FIREPLACE, 2’ above & in frontGAS OVEN on BAKE, 2’ over oven vent, fan offGAS OVEN on BROIL, 2’ over oven vent, fan off

GAS RANGE, 2’ over burner set to high, heating a cold stainless steel pot containing 2” of cold water, with fan off

Left Front = ___________

Left Rear = ___________

Right Front= ___________

Right Rear= ___________

LF = ______

LR= ______

RF= ______

RR= ______

VEHICLE STARTED IN ATTACHED GARAGE, 2’ above hood in while standing in front of vehicle

Max before door is closed=

Max after door is closed=

6


2.4 Tips for Reducing CO Exposures Indoors

1) Replace unvented combustion appliances with vented ones, and preferably with direct or power-vented appliances that cannot backdraft. Power vented furnaces, water heaters and (wall mounted) space heaters are widely available from appliance dealers.

2) If you use a gas oven or range, always turn on an exhaust fan in the kitchen (or open a window) before you turn on the burner. Never leave a gas oven on with the door open to heat the kitchen as this greatly increases the level of CO.

3) If you use an electric oven, always turn on an exhaust fan in the kitchen (or open a window) when baking, broiling or using the oven’s self-clean mode, since all these activities may produce high levels of CO, especially if the inside of the oven is dirty. This CO is not produced by the electric oven, of course, but by the food being baked, broiled or charcoaled inside it.

4) Get all the combustion appliances in your home professionally inspected and tuned (especially gas ovens) at least once per year by a licensed repair person who has a combustion gas analyzer and knows how to use it.

5) Get all the chimneys and flues in your home professionally inspected and cleaned at least once per year.

6) If your home has an attached garage and you use it to store motor vehicle(s), hire an electrician to install a quiet exhaust fan in an outside wall of the garage and wire the fan so that it runs continuously. (Section 403.3 of the International Mechanical Code requires that attached residential garages have 100 cubic feet per minute of continuous exhaust per vehicle, but few builders provide this.) Very quiet and efficient exhaust fans (under 2 sones) are widely available for under $200. They cost less than $25 per year to operate continuously.

7


7) Do not smoke indoors and do not allow others to smoke in your presence.

8) Do not burn incense or lots of candles indoors unless well ventilated.

9) Do not use gas grills, gas generators, or gas power tools indoors.

10) Do not use solvents or spray cans containing methylene chloride indoors, since methylene chloride is easily absorbed by the human body and then metabolized into carbon monoxide.

8


3 Carbon Monoxide in Breath Smokers commonly have higher levels of CO in their exhaled breath than the 9ppm allowed outdoors by the US EPA. While smoking, the level of CO in their breath may even exceed the 200ppm limit set by US NIOSH for the immediate evacuation of any workplace!

3.1 Before Measuring CO In Breath

The level of CO in (exhaled) breath may be higher or lower than the background ambient levels of CO indoors or outdoors, depending on how much CO the person’s lungs are producing (normally less than 2ppm unless the person is highly stressed or chronically ill), how long they may have been exposed to higher ambient levels, and if they have had any additional significant CO exposures within the last few hours (such as from smoking or using a gas oven). The person being tested should be informed and asked in advance about all these possibilities.

CO is produced in the body primarily by the action of heme oxygenase-1, which continuously breaks down heme proteins of all kinds (hemoglobin in blood, myoglobin in muscle, cytochromes in mitochondria, etc) into iron (which is stored as ferritin until the body uses it to make more heme) and equal parts of biliverdin (a potent anti-oxidant that is converted to bilirubin) and CO, which is bioactive in the body as a neurotransmitter, vasodilator and key catalyst in over 100 pathways.

HO-1 is known as the “universal stress enzyme” because its activity (and resulting CO production) are quickly and greatly increased from ten to hundred-fold by human exposures to mental, physical and environmental stressors of any kind, including infections of all kinds, many chronic diseases (including asthma, diabetes and heart disease), and sensory stressors such as bright lights, loud sounds, strong odors, and hot weather.

Several studies report that CO levels in exhaled breath are maximized in the range of parts per million—and thus are detectable with the type of CO detectors recommended in Chapter 1--after people have held their breath for 20 to 25 seconds. To detect breath CO levels in people who cannot hold their breath for at least 15-20 seconds, it may be necessary to use much more expensive detectors (costing approximately $15,000) that can measure exhaled breath CO levels in the range of parts per billion range.

9


Note also that CO levels in exhaled breath have a diurnal rhythm and are normally highest around noon and lowest around midnight. When retesting people, therefore, it is best to do so at approximately the same time of day. Breath CO in menstruating women also varies monthly, peaking at 2-5 times normal during PMS.

3.2 Measuring CO In Breath

The person being tested (the subject) should be directed to sit down and breathe normally for at least 3 minutes before testing. After turning on the detector in clean air (to get a true zero), place it in a clear plastic bag. (The thin type found in the vegetable section of grocery stores works the best.) Roll up the bag tightly around the detector so that all the air inside is forced out (so that the inside of the bag sticks to itself). Holding the bag closed at the top, let it unroll so that the detector falls to the bottom. Ask the subject to hold the bag tightly in one fist, about halfway up from the bottom. Fold the open top of the bag back over their closed fist so that they can blow the bag up like a balloon simply by raising their fist to their mouth, putting their lips tightly on the bag, slightly relaxing their grip, and exhaling forcefully.

In order to collect the higher concentration of CO produced in the bottom of their lungs (known as an “end-tidal” sample), the subject should be taught and shown how to hold their breath for 20 seconds, then blow out away from the bag for the 2 seconds, and then—without re-inhaling—to exhale the rest of their breath into the bag. Some people are not coordinated enough to do this, in which case you should note and explain that their end-tidal CO level sample will be slightly diluted by the lower level of CO produced in their throat and upper airways. After the subject has finished exhaling, they should squeeze their fist tightly to keep their breath from escaping and then twist or twirl the bag around several times beneath their fist in order to keep the bag closed while the digital display of the detector stabilizes (ie. until the CO level no longer rises), which normally takes no more than one or two minutes. The display can be viewed most easily if held against the side of the plastic bag. After the display has stabilized, the detector should be removed from the bag, wiped dry, and allowed to return to zero in room air or outside before being used again. This also usually takes a few minutes. The bag may be reused if retesting the same subject, but a new bag should be used for new subjects.

3.3 Recording CO In Breath A sample form is provided on the next page. For medical insurance billing, code breath CO measurements with CPT 94720. The amount that medical insurance will pay for breath CO measurement varies, of course. In Ohio, for example, Workers’ Compensation was paying $57.99 in 2002.

10


CARBON MONOXIDE LEVELS MEASURED IN BREATH

DATE ____________ TIME ______ AMBIENT CO OUTDOORS = _________PPM

LOCATION _________________________________________________________

MEASURED BY _____________________________________________________

DETECTOR ID _______________ DATE OF LAST CALIBRATION ____________

LEVEL OF CO DETECTED IN EXHALED BREATH = _______ _ PPM (normal = 0-2)

AFTER HOLDING BREATH FOR __ SECONDS (target = 20) AND

THEN BREATHING OUT (AWAY FROM BAG) FOR _______ SECONDS (target = 2)

HISTORY OF RECENT EXOGENOUS (EXTERNAL) EXPOSURES

1. IF SMOKER, NOTE TIME SINCE LAST CIGARETTE = ___________ HOURS

2. IF NON-SMOKER, TIME SINCE LAST SMOKE EXPOSURE = ________ HOURS

3. (ALL) TIME SINCE LAST EXPOSURE TO HEAVY TRAFFIC = ________ HOURS

4. (ALL) TIME SINCE LAST EXPOSURE TO SOLVENTS, PAINT STRIPPER OR SPRAYS THAT MAY HAVE CONTAINED METHYLENE CHLORIDE = ________ HOURS

HISTORY OF RECENT STRESS AND CO-RELATED ILLNESS

5. TYPES OF STRESSORS CAUSING SYMPTOMS IN THE LAST 24 HOURS:

__ MENTAL ___ PHYSICAL (from __ exercise or other: _______________________)

__ ENVIRONMENTAL (from __ light , __ sound, __ odor, __ food, __ touch, __ heat or cold)

6. CO-RELATED DISORDERS CAUSING SYMPTOMS IN THE LAST 24 HOURS:

__ ADD/ADHD __ ALLERGY __ ASTHMA __ AUTISM __ CHRONIC FATIGUE

__ DEPRESSION __ DIABETES __ FIBROMYALGIA __ HEADACHE or MIGRAINE

__ HALLUCINATIONS __ HEART DISEASE __ MCS __ PANIC __ PARANOIA __ PMS

__ PARKINSONS __ PSYCHOSES __ PRE-MENSTRUAL SYNDROME __OTHER:

11


3.4 Tips for Reducing CO In Breath

1. If you smoke, quit! If you don’t smoke, avoid exposures to second-hand smoke.

2. If you suffer from one or more chronic CO-related disorders, ask your doctor to consider treating the chronic CO symptoms of your disorder(s) with supplemental oxygen at home (6 liters/minute for 2 hours/day until symptoms resolve)

3. If you are aware of any stressful exposures or situations that cause you to suffer CO symptoms, reduce these exposures or avoid them entirely. Increase relaxing activities!

4. If you ever have difficulty breathing, try breathing in and out only through your nose, only with your diaphragm (so that your chest and shoulders do not move, while your belly expands on inhalation and contracts on exhalation), and much more slowly. Most adults breathe 10 to 14 times per minute, but the ideal rate to increase oxygen uptake by the body is just 6 breaths per minute, or one breath every 10 seconds. (The authors found that the exact same rhythm is induced by saying the Rosary in prayer or Om Mani Padme Om in meditation!) So the next time you feel short of breath, tired, stressed or ill, try breathing this way for 10 to 15 minutes: inhale through your nose for 4 seconds and then exhale through your nose for 6 seconds. Practice this sitting or lying down before you try it standing up.

5. If you have any combustion appliances or other sources of CO inside your home (gas ovens, ranges, water heaters, space heaters, furnaces, fireplaces, gas power tools, etc), make sure they are directly vented to the outside or at least adequately ventilated (via open windows and fans) whenever you use them. Also have all your combustion appliances inspected and tuned at least once a year by a qualified repair person who has a combustion gas analyzer and knows how to use it.

6. Do not use solvents or spray cans containing methylene chloride indoors, since methylene chloride is easily absorbed by the human body and then metabolized into carbon monoxide.

7. Whenever you are stuck or driving slowly in heavy traffic, leave plenty of distance between your car and the vehicle in front of you. Keep your windows and vents closed until you are moving freely again, when you should open two or more windows to flush out whatever CO may have accumulated inside your vehicle.

8. If your home has an attached garage and you use it to store motor vehicle(s), hire an electrician to install a quiet exhaust fan in an outside wall of the garage and wire the fan so that it runs continuously. Section 403.3 of the International Mechanical Code requires that attached residential garages have 100 cubic feet per minute of continuous exhaust per vehicle, but few builders provide this. They cost under $200 and about $20/year to run.

12


4 Carbon Monoxide in Vehicles

CO from motor vehicles kills more Americans every year than all other CO sources combined. Over 1200 of these CO deaths every year are suicides. Another 200 are unintentional, including over 50 that occur while the victim is driving, usually in heavy traffic.

4.1 Before Measuring CO In Vehicles

The level of CO in vehicles is never lower than the ambient levels of CO outdoors, so the outdoor level should be measured first (away from busy roads and intersections) and then subtracted from whatever levels are measured inside the vehicle. All vehicles produce more CO in cold weather and when their own engine is cold. So to assess worst case scenarios, pick a cold day to measure CO from your vehicle and wait until your engine is also cold (at least 2 hours after you last drove it). Note that in some states, gasoline sold from pumps is oxygenated during winter to reduce CO.

4.2 Measuring CO In Vehicles

CO may enter your vehicle from several sources: from ambient air outside your vehicle; from your vehicle’s own exhaust stream (highest when the engine is cold and first started because the catalytic converter that converts CO to CO2 takes about one minute to warm up and start working; note that CO may be high continuously if there is a leak anywhere between the exhaust manifold and the catalytic converter); and from the exhaust of vehicles around your vehicle, especially the vehicle directly ahead, which is one more reason why you should never tailgate. CO may enter vehicles via open windows, via the heater vents (even if set to “closed” or “recirculate” they do not always shut tightly), via any holes or cracks in the floor or sides of the passenger compartment, or via any gaps in the rubber seals surrounding the doors, windows and trunk.

Since CO may accumulate very quickly inside vehicles that are started in small residential garages (even if the garage door is left open), never idle a vehicle in a garage while measuring CO. If you normally store your vehicle in a garage, you

13


may start it there for this test, but then drive it out as you normally would and shut the door after the vehicle is out.

Before starting your vehicle, close all the windows and fresh air vents, turn off the fan, and place the CO detector securely on the dash where you can see its display without blocking your view of the road (if you tape it in place, be sure you do not tape over the sensor hole).

To measure the infiltration of CO from your own vehicle:

Start and drive your car “cold” as you normally do for 3 minutes, but do not drive in heavy traffic and stay at least 20 feet behind other vehicles. If any CO accumulates inside, open 2 or more windows and keep driving until the CO level falls back to the level outside. The source of this CO is probably your own vehicle’s exhaust coming in through the body of the car or one of the rubber seals. If no CO accumulates inside during the first 3 minutes, park the car and leave the motor running for another 3 minutes (still with all windows and vents closed) to see if any CO accumulates. Then repeat for another 3 minutes with one window cracked open, the fresh air vents open and the fan on high. If CO does accumulate inside, the source is definitely your own vehicle, and (as above) you should open 2 or more windows until the CO level inside falls back to the level outside. You also should have the exhaust system and passenger compartment inspected for leaks as soon as possible.

To measure the infiltration of CO from other vehicles:

Open windows and vents until the level of CO inside your vehicle is the same outside, and then reclose them. Look for an older vehicle (10+years older) and follow it to a red light. Pull up to within about 3 feet of its rear bumper while stopped at the light, and then follow it for a few seconds (at a distance of about 6 feet) when it pulls away after the light turns green. Try this several times with your windows and vents in various configurations (see sample recording form below for details)

If CO begins to accumulate inside the vehicle, open 2 or more windows and keep driving, until the CO level falls to the same as outside. Note that any CO buildup in these situations can usually be avoided by driving (and especially stopping) further behind the vehicle in front of you. If CO accumulates inside while you are driving in heavy traffic inside a tunnel or underground parking garage, you cannot reduce CO by opening the windows, so keep them shut with the vents closed and the fan off until you are back outside in fresh air and then open them.

14


CARBON MONOXIDE LEVELS MEASURED IN VEHICLES

VEHICLE MAKE _________________________ MODEL ________________________

Fuel Type: __ Highest Grade __ Medium Grade __ Lowest Grade (Note that some states require all gasoline to be oxygenated during winter months to reduce CO emissions; note =also that most diesel vehicle engines do not produce significant CO)

Test Date: __________ Location: ____________________ Outside Temp: _____ F

Outdoor CO level measured away from vehicles and other CO sources = ____ppm

CO Detector Location Inside Vehicle:

__ dashboard __ passenger seat __other _______________________________

CO Levels Measured:

1. Maximum within 3 minutes of normal cold startup and driveaway,

a) ______ ppm with all windows closed, vents closed and fan off

2. Maximum within 3 minutes of parking and idling outdoors:

a) ______ ppm with all windows closed, vents closed and fan off

b) ______ ppm with one windows cracked, vents open and fan on high

3. Maximum within 3 minutes of stopping at a light within 3 feet of a 10+ year old vehicle

(and then following about 6 feet behind it as the light turns green).

a) ______ ppm with all windows closed, vents closed (fresh air off) and fan off

b) ______ ppm with all windows closed, vents open and fan on high

c) ______ ppm with one window open cracked, vents open and fan on high

d) ______ ppm with one window open wide open, vents open, and fan on high

e) ______ ppm with two windows wide open, vents closed and fan off

If vehicle is started in a residential garage, walk back inside the garage after driving out, shut the garage door, and note the max. CO level inside = _______ ppm

15


4.4 Tips for Reducing CO In Vehicles

1. Never tailgate other vehicles, especially if stopped or driving slowly in heavy traffic. Always leave plenty of distance between your car and the vehicle in front of you. Keep your windows and the vents closed with the fan off or set to recirculate (especially if in a tunnel) until you are moving freely again, when you should open two or more windows to flush out whatever CO may have accumulated inside.

2. Never park your vehicle with the motor running for more than a few minutes, and never sleep in it with the motor running unless you open two or more windows all the way. Just cracking open your windows does not provide enough ventilation to prevent death if CO is seeping into the passenger compartment.

3. If you start to feel any CO symptoms while driving, such as headache, fatigue, difficulty concentrating, difficulty breathing, or blurred vision, get more fresh air immediately by either opening 2 or more windows wide or stopping the vehicle (safely!) away from traffic and getting out to walk around in fresh air.

4. Keep your vehicle’s exhaust system well maintained, especially the catalytic converter, and always get any leaks in your exhaust system (detectable by the loud noise the results from by-passing the muffler) repaired as soon as possible.

5. If your vehicle is parked in snow, clear at least 2 feet from around the tailpipe before starting the engine. If you need to idle the engine to run the heater for warmth, run the engine with the heater on high but only for a few minutes at a time, and with all the windows cracked while you are doing it. Then shut all the windows until you need to run the engine and heater again.

6. If your home has an attached garage and you use it to store motor vehicle(s), hire an electrician to install a quiet exhaust fan in an outside wall of the garage and wire the fan so that it runs continuously. Section 403.3 of the International Mechanical Code requires that attached residential garages have 100 cubic feet per minute of continuous exhaust per vehicle, but few builders provide this. Quiet exhaust fans cost under $200 to purchase and about $20 per year to run continuously.

16


17


Appendix A : Carbon Monoxide Levels of ConcernCO Level Status of Concern

0-1 ppm Normal level of CO outdoors in clean fresh air 0-2 ppm Normal level of CO in the exhaled breath of healthy adults (after holding their breath

for 20 to 25 seconds, which maximizes CO levels in the lower lung)2-3 ppm Minimum outdoor CO level (average over 8 hours) associated with statistically

significant increase in hospitalizations for asthma and congestive heart disease5.5 ppm Minimum outdoor CO level (average over third trimester of pregnancy) associated

with statistically significant increase in risk of low birth weight5-24ppm Range of CO in the exhaled breath of smokers who have not smoked for several hours

and people with various chronic CO-related disorders including anemia, asthma, bronchiectasis, diabetes, heart disease, multiple chemical sensitivity and PMS.

9 ppm Maximum 8-hour average CO exposure allowed by US EPA outdoors and recommended by ASHRAE indoors

25-50 ppm Range of CO in the exhaled breath of smokers who have smoked in the last hour and non-smokers exposed to high levels of CO in the last few hours.

30 ppm Minimum level above which UL- and CSA-approved home CO alarms are allowed to display the current CO level (display below 30 is not allowed)

35 ppm Maximum 8-hour average CO exposure recommended by US NIOSH for workers and level above which most US fire departments require firefighters to wear their self-contained breathing apparatus.

50 ppm Maximum 8-hour average CO exposure allowed by US OSHA for workers 50-999+ppm Range of CO in the exhaled breath of smokers while smoking, depending on how long

and how deeply they inhale; also found in exhaled breath during acute CO poisoning70 ppm Level above which UL-and CSA-approved home CO alarms are allowed to alarm but

only after being over 70 for 1 to 4 hours. 100 ppm Indoor level above which Baltimore City Fire Department orders evacuation 150 ppm Level above which UL -and CSA -approved home CO alarms are allowed to alarm but

only after being above 150 for 10 to 50 minutes. 200 ppm Indoor level above which US NIOSH recommends immediate evacuation of workers400 ppm Level above which UL -and CSA -approved home CO alarms are allowed to alarm but

only ater being above 400 for 5 to 15 minutes. Also the maximum “air-free” CO level allowed in water heater flues, gas furnace flues and boiler flues by ANSI’s Z.21 standard (unchanged since 1925).

800 ppm Maximum “air-free” CO level allowed from kitchen oven and 4 burners by ANSI’s Z.21 standard (unchanged since 1925, when all ovens were vented, which none now are)

1,200 ppm CO level US NIOSH says is “immediately dangerous to life and health” 50,000-150,000 ppm CO level in gasoline vehicle engine exhaust when catalytic converters are cold,

not maintained properly or not installed (usually falls to under 100ppm within 1 minute)1,000,000 ppm CO level that is instantly lethal if inhaled (pure CO kills neurologically after just 1 breath)

18


Appendix B : References on CO Measurement

CO INDOORS1. Boleij J, Lebret E, Smit J, Brunekreef B, Biersteker K. Indoor air pollution

by carbon monoxide and nitrogen oxides. Schriftenr Ver Wasser Boden Lufthyg. 1982;53:199-208.

2. Etzel RA. Indoor air pollutants in homes and schools. Pediatr Clin North Am. 2001 Oct;48(5):1153-65.

3. Howell J, Keiffer MP, Berger LR. Carbon monoxide hazards in rural Alaskan homes. Alaska Med. 1997 Jan-Mar;39(1):8-11.

4. Stevenson KJ Measurements of CO and nitrogen dioxide in British homes using unflued heating or cooking appliances. Tokai J Exp Clin Med 1985 Aug;10(4):295-301.

5. Wallace L. Real-time monitoring of particles, PAH, and CO in an occupied townhouse. Appl Occup Environ Hyg. 2000 Jan;15(1):39-47.

CO IN BREATH1. Cunnington AJ, Hormbrey P. Breath analysis to detect recent exposure to carbon monoxide.

Postgrad Med J. 2002 Apr;78(918):233-7.2. Ece A, Gurkan F, Haspolat K, Derman O, Kirbas G. Passive smoking and expired carbon

monoxide concentrations in healthy and asthmatic children. Allergol Immunopathol (Madr). 2000 Sep-Oct;28(5):255-60.

3. Gourgoulianis KI, Gogou E, Hamos V, Molyvdas PA. Indoor maternal smoking doubles adolescents' exhaled carbon monoxide. Acta Paediatr. 2002;91(6):712-3.

4. Jaslow D, Ufberg J, Ukasik J, Sananman P. Routine carbon monoxide screening by emergency medical technicians. Acad Emerg Med. 2001 Mar;8(3):288-91.

5. Monma M. Yamaya M, Sekizawa K. Ikeda K. Suzuki N, Kikuchi T. Takasaka T. and Sasaki H. Increased carbon monoxide in exhaled air of patients with seasonal allergic rhinitis. Clinical and Experimental Allergy 29:1537-1541, 1999.

6. Verhoeff AP, van der Velde HC, Boleij JS, Lebret E, Brunekreef B. Detecting indoor CO exposure by measuring CO in exhaled breath. Int Arch Occup Environ Health. 1983;53(2):167-73.

7. Vreman HJ, Wong RJ, Stevenson DK. Exhaled carbon monoxide in asthma. J.Pediatr.2000.Dec.;137.(6.):889.-90. 2000;137:889-90.

CO IN VEHICLES1. Alm S, Jantunen MJ, Vartiainen M. Urban commuter exposure to particle

matter and carbon monoxide inside an automobile. J Expo Anal Environ Epi. 1999 May-Jun;9(3):237-44.

2. Flachsbart PG. Models of exposure to carbon monoxide inside a vehicle on a Honolulu highway. J Expo Anal Environ Epidemiol. 1999 May-Jun;9(3):245-60.

19


3. Flachsbart PG. Long-term trends in United States highway emissions, ambient concentrations, and in-vehicle exposure to carbon monoxide in traffic. J Expo Anal Environ Epidemiol. 1995 Oct-Dec;5(4):473-95.

4. Ott W, Switzer P, Willits N. Carbon monoxide exposures inside an automobile traveling on an urban arterial highway. Air Waste. 1994 Aug;44(8):1010-8

20

Documents

CO Measurement Protocols