Designed, built and supported by industry professionals for industry professionals.
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I. INTRODUCTION
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Part 1 Monitoring Breathing Air
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A chemical plant worker inspecting a tank car cleaning operation, a fire
fighter donning his self-contained breathing apparatus, and a SCUBA
diver on a weekend holiday all face a common situation. Each is putting
his or her life on the line by hooking up to a temporary air supply.
Assured that by using a life-supporting device he/she is being provided
maximum protection, the quality of that breathing air is probably the last
thing on his or her mind.
A quantitative testing device is the only way to assure that the breathing
air quality meets minimum standards. The faster, easier, and less
expensive such testing is, the more often it can be applied.
A compressed breathing air system has two potential sources of
contaminants: (1) those entering the system with the intake air and
(2) those produced internally by a faulty compressor or inadequate
filtration system. An example of the first type would be vehicle exhaust
intrusion caused by locating the compressor air inlet too close to traffic
areas or loading zones. An example of the second type might be oil mist
accumulation caused by an overfilled oil reservoir and inadequate filter.
Some common breathing air contaminants are carbon monoxide, carbon
dioxide, nitrogen oxides, oil mist, and water vapor, as well as oxygen
deficiency.
• Carbon Monoxide
Of the common potential contaminants, CO is the most deadly. It is
colorless and odorless with no warning properties. CO combines
with blood hemoglobin more readily than oxygen causing oxygen
starvation in body tissues. Exposure causes headaches, heart
palpitations, and loss of equilibrium, confusion, unconsciousness,
and death.
• Carbon Dioxide
CO2 is also toxic but can be tolerated in much higher concentrations
than CO. Effects are somewhat similar to CO, but the increased
breathing rate accompanying CO2 poisoning increases the intake
of all coexisting contaminants. Exposure causes headaches,
dizziness, sweating, shortness of breath, increased heartbeat and
blood pressure, coma, asphyxiation, and convulsions.
