Engine Emissions And Co Safety - Nilfisk PBU 56381410 Manuel D'utilisation

A-4 / ENGLISH

ENGINE EMISSIONS AND CO SAFETY

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:
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
Total time interval and PPM 8 HR
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 hemoglobin 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 concentration 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%
carboxyhemoglobin 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 unconsciousness may occur suddenly without warning.
AIR QUALITY MONITORING
WARNING!
Deployment of a monitor/detector is essential for the safe operation of any equipment that has the potential to produce CO. CO sensors/detectors became
available on the mass market around 1978. At present several brands sell in the fi fty-dollar range. The main differences between the technologies involved are
battery or electric and Semiconductor or Biomimetic types. Detectors for carbon monoxide (CO) are manufactured and marketed for use in either the home or
occupational industrial settings. The detectors for home use are devices that will sound an alarm before CO concentrations in the home become hazardous.
There is an Underwriters Laboratories, Inc., performance standard (UL 2034) for residential CO detectors. Detectors currently available on the market are battery-
powered, wall mount, Operator worn portable personal protective, plug-in, or hard-wired. Some models incorporate a visual display of the parts per million (ppm)
concentration of CO present in the home. For more information on CO detectors for home use, call the Consumer Product Safety Commission Hotline at 1-800-
638-2772. CO detectors for use in residential settings are not designed for use in typical workplace settings. Monitoring requirements in an occupational setting
are different from monitoring requirements in the home. In the workplace, it is frequently necessary to monitor a worker's exposure to carbon monoxide over an
entire work shift and determine the time-weighted average (TWA) concentration of the exposure. It may also be necessary to have carbon monoxide monitors
with alarm capabilities in the workplace. The direct-reading instruments are frequently equipped with audio and/or visual alarms and may be used for area and/or
personal exposure monitoring. Some have microprocessors and memory for storing CO concentration readings taken during the day. It is signifi cant to note that
some of the devices mentioned for workplace CO monitoring are not capable of monitoring TWAs, and not all are equipped with alarms. The appropriate personal
protective monitor must be chosen on an application-by-application basis. For more information on the availability of workplace CO monitors or their application,
call the National Institute for Occupational Safety and Health at 1-800-35-NIOSH (1-800-356-4674).
A-4 - FORM NO. 56091024 - PBU Propane Stripper
PPM
100
25
25
50
50 Total 400ppm/8HR=50ppm TWA
50
50
50
Total ppm = 400k
revised 3/11