Teledyne 4220 installation and operation guide N2O

4220 Flow Meter

Appendix D General Safety Procedures

			Table D-1 Hazardous Gases (Continued)
			Specific		Max	Max. Safe	Explosive		Likely		Simplest and
			Gravity				Range (% by		Location	Most
	Chemical	Common		Physiological	Safe 60	8 Hour					Cheapest
Gas			or Vapor				vol. in air)		of	Common
	Formula	Properties		Effect	Min. Exposure	Exposure					Safe Method
			Density				Limits		Highest	Sources
					ppm	ppm					of Testing
			Air =1				lower/upper		Concentration
Gas	Chemical	Common	Specific	Physiological	Max	Max.	Explosive Range		Likely	Most	Simplest and
	Formula	Properties	Gravity or	Effect*	Safe	Safe	(% by vol.		Location	Common	Cheapest
			Vapor		60 Min.	8 Hour	in air.)		of	Sources	Safe Method
			Density		Exposure	Exposure	Limits		Highest		of Testing
			Air = 1		ppm	ppm	lower/upper		Concentration
Hydro-	H2S	Irritant and poi-	1.19	Impairs sense	200	20	4.3		Near bottom,	Coal gas,	1. H2S
gen Sul-		sonous volatile		of smell, rap-	to				but may be	petro-	Ampoule.
fide		compound. Rot-		idly as concen-	300		45.0		above bottom if	leum,
		ten egg odor in		tration					air is heated and	sewer gas.	2. 5% by weight
		small concentra-		increases.					highly humid.	Fumes	lead acetate
		tions. Exposure		Death in few						from blast-	solution.
		for 2 to 15 min. at		minutes at						ing under
		0.01% impairs		0.2%. Exposure						some con-
		sense of smell.		to 0.07 to 0.1%						ditions.
		Odor not evident		rapidly causes						Sludge gas.
		at high concen-		acute poison-
		trations. Color-		ing. Paralyzes
		less. Flammable.		respiratory
				center.
Methane	CH4	Simple asphyx-	0.55	Acts mechani-	Probably no limit,	—	5.0	15.0	At top, increas-	Natural	1. Combustible
		iant.		cally to deprive	provided oxygen				ing to certain	gas, sludge	gas indicator
		Colorless, odor-		tissues of oxy-	percent-age is suf-				depth.	gas, manu-
		less, tasteless,		gen. Does not	ficient for life.					factured	2. Oxygen defi-
		flammable.		support life.						gas, sewer	ciency indica-
										gas. Strata	tor.
										of sedi-
										mentary
										origin. In
										swamps or
										marshes.
Nitrogen	N2	Simple asphyx-	0.97	Physiologically	—	—	—	—	Near top, but	Sewer gas.	Oxygen
		iant. Colorless,		inert.					may be found	sludge gas.	deficiency
		tasteless.							near bottom.	Also issues	indicator.
		Non-flammable.								from some
		Principal constit-								rock strata.
		uent of air. (about
		79%).
Nitrogen	NO	Colorless	1.04	60 to 150 ppm	50	10	—	—	Near bottom.	Industrial	NO2 detector
Oxides				cause irritation						wastes.	tube.
	N2O	Colorless,		and coughing.						Common
		sweet odor.	1.53							air pollut-
				Asphyxiant.						ant.
	NO2	Reddish-brown.	1.58
		Irritating odor.		100 ppm dan-
		Deadly poison		gerous.
				200 ppm fatal.
Oxygen	O2	Colorless, odor-	1.11	Normal air con-	—	—	—	—	Variable at dif-	Oxygen	Oxygen defi-
		less, tasteless.		tains 20.8% of					ferent levels.	depletion	ciency indica-
		Supports com-		O2. Man can tol-						from poor	tor.
		bustion.		erate down to						ventila-
				12%. Minimum						tion and
				safe 8 hour						absorp-
				exposure, 14 to						tion, or
				16%. Below 10%,						chemical
				dangerous to						consump-
				life. Below 5 to						tion of
				7% probably						oxygen.
				fatal.
Ozone	O3	Irritant and poi-	1.66	Max. naturally	0.08	0.04	—	—	Near bottom.	Where	Detectable
		sonous. Strong		occurring level						ozone is	odor
		electrical odor.		is 0.04 ppm.						used for	at 0.015 ppm.
		Strong oxidizer.		0.05 ppm						disinfec-
		Colorless. At 1		causes irrita-						tion.
		ppm, strong sul-		tion of eyes and
		fur-like odor.		nose. 1 to 10
				ppm causes
				headache, nau-
				sea; can cause
				coma. Symp-
				toms similar to
				radiation dam-
				age.

D-8