ISCO 4210 - Page 170

4210 Flow Meter
Appendix C General Safety Procedures
C-8
Methane CH
4
Simple asphyxiant.
Colorless, odorless,
tasteless, flammable.
0.55 Acts mechanically to
deprive tissues of oxy-
gen. Does not support
life.
Probably
no limit,
provided
oxygen
per-
cent-age
is suffi-
cient for
life.
— 5.0 15.0 At top, increas-
ing to certain
depth.
Natural gas,
sludge gas, man-
ufactured gas,
sewer gas. Strata
of sedimentary
origin. In
swamps or
marshes.
1. Combustible
gas indicator
2. Oxygen defi-
ciency indicator.
Nitrogen N
2
Simple asphyxiant.
Colorless, tasteless.
Non-flammable. Prin-
cipal constituent of air.
(about 79%).
0.97 Physiologically inert. — — — — Near top, but
may be found
near bottom.
Sewer gas.
sludge gas. Also
issues from
some rock strata.
Oxygen
deficiency
indicator.
Nitrogen
Oxides
NO
N
2
O
NO
2
Colorless
Colorless,
sweet odor.
Reddish-brown.
Irritating odor.
Deadly poison
1.04
1.53
1.58
60 to 150 ppm cause
irritation and coughing.
Asphyxiant.
100 ppm dangerous.
200 ppm fatal.
50 10 — — Near bottom. Industrial
wastes.
Common air
pollutant.
NO
2
detector
tube.
Oxygen O
2
Colorless, odorless,
tasteless. Supports
combustion.
1.11 Normal air contains
20.8% of O
2
. Man can
tolerate down to 12%.
Minimum safe 8 hour
exposure, 14 to 16%.
Below 10%, dangerous
to life. Below 5 to 7%
probably fatal.
— — — — Variable at dif-
ferent levels.
Oxygen deple-
tion from poor
ventilation and
absorption, or
chemical con-
sumption of oxy-
gen.
Oxygen defi-
ciency indicator.
Ozone O
3
Irritant and poison-
ous. Strong electrical
odor. Strong oxidizer.
Colorless. At 1 ppm,
strong sulfur-like odor.
1.66 Max. naturally occur-
ring level is 0.04 ppm.
0.05 ppm causes irrita-
tion of eyes and nose. 1
to 10 ppm causes
headache, nausea; can
cause coma. Symp-
toms similar to radia-
tion damage.
0.08 0.04 — — Near bottom. Where ozone is
used for disin-
fection.
Detectable odor
at 0.015 ppm.
Sludge
Gas
—*** Mostly a simple
asphyxiant. May be
practically odorless,
tasteless.
Variable Will not support life. No data. Would
vary widely with
composition.
5.3 19.3 Near top of
structure.
From digestion
of sludge.
See compo-
nents.
Sulfur
Dioxide
SO
2
Colorless, pungent
odor. Suffocating, cor-
rosive, poisonous,
non-flammable.
2.26 Inflammation of the
eyes. 400 to 500 ppm
immediately fatal.
50
to
100
10 — — At bottom, can
combine with
water to form
sulfurous acid.
Industrial waste,
combustion,
common air pol-
lutant.
Detectable taste
and odor at low
concentration.
To lu e n e C
5
H
12
to
C
9
H
20
Colorless, benzene-like
odor.
3.14 At 200-500 ppm, head-
ache, nausea, bad taste,
lassitude.
200 100 1.27 7.0 At bottom. Solvent. Combustible gas
indicator.
Turpentine C
10
H
16
Colorless, Characteris-
tic odor.
4.84 Eye irritation. Head-
ache, dizziness, nau-
sea, irritation of the
kidneys.
— 100 At bottom. Solvent, used in
paint.
1. Detectable
odor at low
concentrations.
2.Combustible
gas indicator.
Xylene C
8
H
10
Colorless, flammable 3.66 Narcotic in high con-
centrations. less toxic
than benzene.
— 100 1.1 7.0 At bottom. Solvent Combustible gas
indicator.
* Percentages shown represent volume of gas in air.
** For concentration over 0.3%.
***Mostly methane and carbon dioxide with small amounts of hydrogen, nitrogen, hydrogen sulfide, and oxygen; occasionally traces of carbon monoxide.
Table C-1 Hazardous Gases (Continued)