CO Carbon Monoxide Awareness
Carbon Monoxide Awareness
CO
1 . CO : Sources CO is generated environmentally in combustion
processes due to incomplete oxidation of carbon and carbonaceous
fuels. Common sources of CO indoors are: fuel-powered vehicles such
as fork lift trucks, poorly ventilated or malfunctioning heating
furnaces, fuel-powered equipment, and welding.Important Home hazard
!
1 . CO : Sources
Engine RoomCraneHot Work PlacesConfined SpacesForkliftExhausts
Mud ?
Home hazard vs Offshore Hazard
2 . CO : Physical propertiesFlammable ( Coal gas ) : 12,5 74 % ,
1100 FColorlessOdorlessSoluble in waterNon irritating No Warning
Properties !Interfere with the Oxygen carrying capacity of the
blood .
3 . CO : Health Effects
3 . CO : Health Effects
CO binds to hemoglobin ( oxygen carrying protein in blood ) 200
250 x more readily than Oxygen and form Carboxyhemoglobin
COHbConcentration in the air of 200 ppm or greater of CO can cause
headaches and nausea after a few hours and can become
dangerous.
3 . CO : long term exposureCO does not accumulate in the body.
Once an exposure ends, the lungs exhale CO and COHb reverts back to
Oxyhemoglobin, the form of hemoglobin that can carry oxygenHalf of
the CO in the blood will be removed in approximately 5 hours. This
half-life can be reduced by breathing pure oxygen or using a
hyperbaric chamber ( first aid / medical treatment ).COHb can occur
in normal humans. A COHb level in blood of 1%-3% would be normal in
a non-smoker. Heavy smokers may have levels of 5%-10%.
4 . CO : Occupational Exposure StandardsOSHA PEL ( Permissible
Exposure Limit , based on an 8- hours time-weighted average )50 ppm
( 35 ppm - NIOSH )NIOSH Ceiling Value ( Should not be exceeded at
any time )100 ppmNIOSH IDLH ( Immediately dangerous to Life and
Health ) IDLH The airborne concentration for which a worker could
escape without injury or irreversible health effects in the event
of the failure of respiratory protection equipment , in 30 min
time1200 ppm
5 . Comparing Toxic GasesGas typeChemical symbolGravityThreshold
limit valueHazard limitLethalconcentrationHydrogen cyanideHCN0,945
ppm 50 ppm 300 ppmHydrogen sulphideH2S1,195 ppm250 ppm600
ppmSulphur dioxideSO22,210,5 ppm100 ppm1000 ppmCarbon
monoxideCO0,9750 ppm400 ppm3200 ppmCarbon dioxideCO21,520,5 %4 %20
% MethaneCH40,55 9 %50%70%
96 . CO : Detection
Canaries were used as an early detection system to Carbon
Monoxide in Coal mines In general two birds were used
Electronic portable detectors Fixed detection system
Colorimetric tubes
7 . CO Contingency / Procedures
How can employers help prevent CO poisoning ?
Install an effective ventilation system that will remove CO from
work area . Maintain equipment and appliance which can produce CO
in good working order . Prohibit the use of gasoline powered tools
in poorly ventilated areaTest air regularly in areas where CO may
be present , including confined spaces .Provide adequate
respiratory protectionEducate workers about the sources and
conditions that may result in CO poisoning
What can employees do to help prevent CO poisoning ?
Report any situation to your employer that might cause CO to
accumulate . Be alert to ventilation problems Report promptly
complains of dizziness , drowsiness or nausea .Avoid overexertion
if you suspect CO poisoning and leave the contaminated area .
QUESTIONS
