Diamatic 08013A, 08014A Libro De Instrucciones página 5

Potential Effects of CO Exposure
· Work place/industry guidelines for CO exposure limits
· Defi nition of CO effects
Work place/industry guidelines for CO exposure limits
Limits for permissible exposure to CO vary substantially from region to region. City, State, and Industry
requirements should be consulted prior to use of any equipment.
The current Occupational Safety and Health Administration (OSHA) Permissible Exposure Limit (PEL)
for CO is 50 ppm, as an 8-hour time weighted average (TWA). This is computed by making measurements at
intervals over 8 hours, then adding the sums of the concentrations and the intervals, and dividing by 8 hours.
For example:
The current National Institute for Occupational Health and Safety (NIOSH), immediately dangerous to life
and health concentration (IDLH) recommended level for CO is 1,200 ppm. NIOSH defi nes the IDLH exposure
level as the concentration that could result in irreversible health effects or death, or prevent escape from the
contaminated environment within 30 minutes.
Defi nition of CO effects
The toxic effects of carbon monoxide in the blood are the result of tissue hypoxia (lack of oxygen). carbon
monoxide combines with hemoglobin to form carboxyhemoglobin. Since CO and oxygen react with the same
group in the hemoglobin molecule, carboxyhemoglobin is incapable of carrying Oxygen. The affi nity of he-
moglobin for CO is 200 to 240 times greater than for oxygen. The extent of saturation of hemoglobin with CO
depends on the concentration of the gas, the quantity of inspired air and on the time of exposure. The severity
depends on the state of activity of the individual and his tissue oxygen needs.
According to Harrison's Principles of Internal Medicine 7th edition, no symptoms will develop at a concen-
tration of 0.01% CO (100ppm) in inspired air, since this will not raise blood saturation above 10 %. Exposure
to 0.05% (500ppm) for 1 hour during light activity will produce a blood concentration of 20% carboxyhemoglo-
bin and result in a mild or throbbing headache. Greater activity or longer exposure causes a blood saturation
of 30 to 50 %. At this point head ache, irritability, confusion, dizziness, visual disturbance, nausea, vomiting,
and fainting can be experienced. Exposure for one hour to concentrations of 0.1% (1000ppm) in inspired air
the blood will contain 50 to 80% carboxyhemoglobin which results in coma, convulsions, respiratory failure
and death. On inhalation of high concentrations of CO, saturation of the blood proceeds so rapidly that uncon-
sciousness may occur suddenly without warning.
BLASTRAC Operator's Manual (EN) - Concrete Polisher
Engine Emissions and CO Safety
Time Interval
8:00-9:00 1 HR
9:00-10:00 1 HR
10:00-11:00 1 HR
11:00-12:00 1 HR
12:00-1:00 1 HR
1:00-2:00 1 HR
2:00-3:00 1 HR
3:00-4:00 1 HR
Time intervals = 8 HR
PPM
100
25
25
50
50 400ppm/8HR=50ppm TWA
50
50
50
ppm = 400
ENGLISH
EN
FORM NO. 71511A - 5 -