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D-303363 MCT-442 SMA Installation Guide
Appendix B - CO Gas Health Effects
B-1. Toxic Effects
Carbon monoxide (CO) is a colorless, odorless non-irritating gas
which is classified as a chemical asphyxiate whose toxic action is a
direct result of the hypoxia produced by a given exposure.
CO is rapidly absorbed through the lungs, diffuses across the alveolar
capillary membrane and is reversible bound with hemoglobin as
carboxyheoglobin (COHb), however a minute amount is present in
the plasma. The affinity of hemoglobin for CO is over 200 times its
affinity for oxygen. This reduces the oxygen carrying of the blood and
also has an effect on dissociation of oxyhemoglobin which farther
reduces the oxygen supply to the tissues. CO is chemically
unchanged in the body and is eliminated in the expired air. The
elimination is determined by the same factors that applied during
absorption.
If the Co level in the inhaled air is constant, the level of COHb in the
blood will approach an equilibrium state after several hours. However,
the rate at which the equilibrium is reached depends on many factors,
e.g. lung ventilation rate (physical activity) and alveolar capillary
transfer, cardiac parameters, blood hemoglobin concentration,
barometric pressure, oxygen and carbon dioxide concentration in the
inhaled air, but the two most important factors in determining the
COHb level are the CO concentration and the duration of exposure.
The effects of different saturation blood COHb levels on healthy
adults are shown in table A1.
Table 1 - Health effects of COHb blood levels on healthy adults
% COHb
Effects
03 - 0.7
Normal range in non-smokers due to endogenous
production
0.7 - 2.9
No proven physiological changes
2.9 - 4.5
Cardio-vascular changes in cardiac patients
4 - 6
Usual values observed in smokers, impairment in
psychomotor tests
7 - 10
Cardio-vascular changes in non-cardiac patients
(increased cardiac output and coronary blood flow)
10 - 20
Slight headache, weakness, potential burden on fetus
20 - 30
Severe headache, nausea, impairment in limb
movements
30 - 40
Severe headache. irritability, confusion, impairment in
visual acuity, nausea, muscular weakness, dizziness
40 -50
Convulsions and unconsciousness
60 - 70
Coma, collapse, death
Source: US Environmental Protection Agency 1984
The following symptoms are related to CO poisoning and are to be
discussed with ALL members of the household:
1. Mild Exposure: Slight headache, nausea, vomiting, fatigue (often
described as "Flu-like" symptoms).
2. Medium Exposure: Severe throbbing headache, drowsiness, fast
heart rate.
3.
Extreme Exposure: Unconsciousness, convulsions, cardio
respiratory failure, death.
4. Many cases of reported CO poisoning indicate that while victims
are aware they are not well, they become so disordered they are
unable to save themselves by either exiting the building or calling
for assistance. Young children and household pets are typically
first affected.
B-2. Chronic Effects on High Risk Group
Individuals with coronary artery disease exposed to low levels of CO
showed reduced ability to exercise. The time of onset of exercise-induced
angina pectoris in such patients exposed to low levels of CO is reduced.
Carbon monoxide readily crosses the placental barrier and may endanger
the normal development of the fetus.
A number of high risk groups are particularly sensitive to the effects of
CO because of various organ impairments or specific changes,
mainly:
a. Those whose oxygen carrying capacity is decreased due to anemia
or other hemoglobin disorders.
b. Those with increased oxygen needs such as those encountered in
fever, hyperthyroidism or pregnancy.
c. Those with systematic hypoxia due to respiratory insufficiency.
d. Those with hearth disease and any vascular insufficiency, such as
cerebral ischaemia and peripheral vascular diseases.
B-3. Normal COHb levels
Under normal conditions all humans have low levels of COHb of
between 0.3% and 0.7% present within the body. These levels are
considered neither beneficial nor harmful.
B-4. Tobacco Smoking
Tobacco smokers are exposed to significant concentration of CO. In
cigarette smokers the COHb concentration varies between 5% - 9%
while heavy smokers it may exceed 10%.
Appendix C - Action to Take When Alarm Sounds
In case of harmful levels of CO gas is detected, your detector will go
into continuous full alarm, Try to take the following necessary actions
immediately:
1. Push the detector TEST switch to silence the alarm.
!
Warning: Never remove the battery to silence the alarm.
Removing the battery removes your protection!
2. Call your emergency service (tel. No. .............), or fire department
(tel. No. ............). (Please write the telephone numbers).
3.
Immediately move to fresh air
- outdoors or by opening
door/window. Do a head count to check that all persons are
accounted for. Do not reenter the premises nor move away from
the open door/window until the emergency services responders
have arrived, the premises have been aired out, and your alarm
remains in normal condition.
4. After following steps 1 - 3, if your alarm reactivates within 24 hours
period, repeat steps 1 - 3 and call qualified technician (Tel. No.
........) to investigate for sources of CO gas from fuel burning
equipment and appliances, and inspect for proper operation of this
equipment. If problems are identified during this inspection, have
the equipment serviced immediately. Note any combustion
equipment not inspected by the technician and consult the
manufacturer instructions, or contact the manufacturers directly,
for more information about CO safety and this equipment. Make
sure that motor vehicles are not, and have not been, operating in
an attached garage or adjacent to the residence.
!
Warning:
Normally an activation of the detector indicates the
presence of CO gas. However, the CO gas can be extremely fatal, if it
is not detected. The source of the CO gas may come from several
possible situations.
Caution:
This detector will only indicate the presence of CO gas at
the sensor. However, you have to be aware that the CO gas may be
present in other areas in the premises.
Action to be taken after the problem has been corrected
Once the problem about the CO gas presence in the premises has
been corrected, the detector's alarm should be off. After waiting for 10
minutes, push the Test button, to verify that the detector is properly
working again.
