• Test the alarm weekly by pressing the
test/hush button. The horn will sound at
a diminished sound output level initially
and then quickly reach maximum sound
output level.
• Replace alarm after approximately 10
years operation (see ‘replace by’ date
on label).
• Do not install alarm until all building work
is completed to avoid contamination.
• Individuals with medical problems may
consider warning devices which provide
audible and visual signals for carbon
monoxide concentrations under 30ppm.
2. Carbon Monoxide - The
Silent Killer
2.1 What is carbon monoxide?
Many people are killed each year, and
many more suffer ill health from carbon
monoxide (CO) poisoning. CO is an
invisible, odorless, tasteless and extremely
toxic gas. It is produced by appliances and
vehicles burning fuels, such as coal, oil,
natural/bottled gas, paraffin, wood, petrol,
diesel, charcoal, etc. CO is absorbed by
red blood cells in the lungs in preference
to oxygen - this results in rapid damage
to the heart and brain from oxygen
starvation.
High levels of CO in a house can be
caused by:
• Incorrectly or poorly installed fuel-burning
appliances
• Blocked or cracked chimneys/flues
• Blocked vents or draft-proofing
which makes areas with fuel-burning
appliances or fireplaces airtight
• Engines of cars, lawnmowers, etc. left
running in confined spaces
• Portable paraffin or gas heaters in badly
ventilated rooms
2.2 What happens when your CO Alarm
detects Carbon Monoxide?
When the Alarm detects potentially
dangerous levels of CO, it flashes the red
alarm light immediately and then sounds
a loud alarm if the CO persists. Table
B shows how the CO Alarm reacts to
different levels of CO gas and exposure
time. At higher levels of CO the alarm
turns on sooner. The rate of flashing of
the red light indicates the level of CO.
If your CO Alarm sounds, follow the
instructions in Section 6.
NEVER IGNORE
THE ALARM!
3
2.3 Symptoms of CO Poisoning
CO in
PPM
Symptoms
35
The maximum allowable
concentration exposure
in any 8 hour period
according to OSHA
150
Slight headache after 1.5
hours
200
Slight headache, fatigue,
dizziness, nausea after 2-3
hours
400
Frontal headaches
within 1-2 hours, life
threatening after 3 hours,
also maximum parts per
million in flue gas (on an
air free basis) according
to US Environmental
Protection Agency.
800
Dizziness, nausea and
convulsions within 45
minutes. Unconsciousness
within 2 hours. Death within
2-3 hours.
1600
Headache, dizziness, and
nausea within 20 minutes.
Death within 1 hour.
3200
Headache, dizziness and
nausea within 5-10 minutes.
Death within 25-30 minutes.
6400
Headache, dizziness and
nausea within 1-2 minutes.
Death within 10-15 minutes.
12800
Death within 1-3 minutes
The following symptoms may be related
to Carbon Monoxide Poisoning and
should be discussed with all members of
the household:
Mild exposure
: Headaches, running
nose, sore eyes, often described as “flu
like symptoms”
Medium Exposure
: Dizziness,
drowsiness, vomiting
Extreme Exposure:
Unconsciousness,
brain damage, death
Many cases of reported carbon
monoxide poisoning indicate that while
victims are aware they are not well, they
become so disoriented they are unable
to save themselves by either exiting the
building or calling for assistance.
