Connecticut Administrative Code › Title 19 - Public Health and Safety › 66c - Compressed Air Used in Self-contained Underwater Breathing Apparatus › Section 19-66c-1 - Testing procedures for air for scuba diving

Current through July 10, 2024
The following tests should be done on a sample of air obtained
				from the compressor after it has been in operation for at least ten minutes
				thereby permitting observation of the effects of heating the motor.
(a)
Oxygen: 20-21 percent.
Compressed ambient air will be considered to meet the oxygen standard without
			 testing. If such tests are required, a sample blown into a plastic bag, such as
			 polyvinyl chloride (pvc) film or aluminized Scotchpak or flushed through an
			 all-glass evacuated flask, may be analyzed with an oxygen indicator such as the
			 Portable Oxygen Indicator of the Portable Gas Analyzer.
(b)
Carbon dioxide: Less than.03
			 percent (300 ppm).
Compressed ambient air will be considered to meet the
			 carbon dioxide standard without testing. If such tests are required, a sample
			 blown into a plastic bag, such as pvc or aluminized Scotchpak or flushed
			 through an all-glass evacuated flask, may be analyzed with a gas analysis
			 apparatus or with gas detector tubes such as the Kitagowa Gas
			 Detector.
(c)
Carbon
			 monoxide: Less than .001 percent (10 ppm).
Carbon monoxide may be
			 analyzed by first collecting an air sample directly from the compressed gas
			 tank or compressor into a plastic bag, such as pvc or aluminized Scotchpak, or
			 into an all-glass evacuated flask. The collected sample may be analyzed by
			 means of direct reading indicating tubes or by means of a direct reading CO
			 Indicator, or by means of the laboratory techniques with iodine pentoxide or
			 infrared spectrophotometry.
(d)
Oil mist: Less than 5
			 mg/M
3
.
Oil mist may
			 be analyzed by first collecting an air sample on oil-free silica gel or on a
			 molecular filter sampler. Since oil droplets tend to settle on the walls of any
			 holding container, the air sample should be passed directly from the air
			 compressor or air tank to the silica gel or molecular filter sampler.
When the sample is collected on silica gel, the oil may be
				analyzed by extraction with a known volume of carbon tetrachloride and compared
				for fluorescence under a "dark lamp", using known quantities of S.A.E. No. 30
				petroleum lubricating oil in carbon tetrachloride for standards.
An alternate method may be used, by collecting a known volume
				of air on a molecular filter sampler and comparing the "black light"
				fluorescence with known standard quantities of S.A.E. No. 30 oil. For example,
				with the "RV Black Light", a 30 microgram quantity of lubricating oil can be
				detected on a 47 mm molecular filter paper. Thus a 6 liter air sample, through
				a molecular filter, will detect a concentration of 5
				mg/M3 of oil mist. Repeated samples, at higher or
				lower total air volume, can be collected to estimate the magnitude of oil mist
				concentration.
Mineral or silicone oil which occasionally are used for
				compressor lubrication do not fluoresce under ultraviolet light. Where these
				oils are used assay should be done by gravimetric analysis at a micro-chemical
				laboratory.
(e)
Total
			 oxidants: Less than 0.05 ppm.
Total oxidants in compressed air may be
			 analyzed by two methods:
(1) A 20 liter air
			 sample may be collected directly from the tank or compressor into an all-glass
			 midget impinger of fritted glass absorber sampler, containing 10 ml of
			 phenolphthalein reagent.
(2) A 20
			 liter sample may be collected in a Mylar plastic bag and returned to a
			 microchemical testing laboratory for analysis by the phenolphthalein reagent
			 method. Since total oxidants in air are not chemically stable, their analysis
			 should be undertaken within a few hours of collection.