Hazardous Gases - Teledyne 4220 Installation And Operation Manual

4220 Flow Meter
Appendix D General Safety Procedures
D.3 Hazardous Gases
Chemical Common
Gas
Formula Properties
Ammonia NH Irritant and
3
poisonous. Col-
orless
with characteris-
tic
odor.
Benzene C H Irritant, colorless
6 6
anesthetic
Carbon CS Nearly odorless
2
Bisulfide when pure, color-
less, anesthetic.
Poisonous.
D-6
number of harmful vapors. They, too, are sensed by smell and
explosimeter tests if they get into the public sewer. Such occur-
rences are rare.
"The attempt to instill a sense of urgency about real hazards is
diluted if a man is told to give attention to a long list of things
that in fact are irrelevant.
"Be very careful to avoid high H
atmospheres, and hazards of physical injuries. Remember that
much H S may be released by the stirring up of sludge in the
2
bottom of a structure. Obey your senses in respect to irritating
gases, such as chlorine (unconsciousness comes suddenly from
breathing too much). Be cautious about strange odors. Do not
determine percent oxygen in the air. There is a danger that the
result will influence a man's thinking about the seriousness of
the real hazards. Most important, use ample ventilation, and do
not enter a potentially hazardous structure except in a good
safety harness with two men at the top who can lift you out."
The following table contains information on the properties of

hazardous gases.

Table D-1 Hazardous Gases
Specific
Max
Gravity
Physiological Safe 60
or Vapor
Effect Min. Exposure
Density
ppm
Air =1
0.60 Causes throat 300
and
eye irritation at 500
0.05%, cough-
ing
at 0.17%. Short
exposure at
0.5%
to 1% fatal.
2.77 Slight symp- 3,000
toms
after several 5,000
hours
exposure at
0.16% to 0.32%.
2% rapidly
fatal.
2.64 Very poison-
ous,
irritating, vom-
iting,
convulsions,
psychic distur-
bance.
S concentrations, flammable
2
Explosive
Max. Safe
Range (% by
8 Hour
vol. in air)
Exposure
Limits
ppm
lower/upper
85 16 25
to
25 1.3 7.1
to
— 15 1.3 44.0
Likely
Simplest and
Location Most
Cheapest
of Common
Safe Method
Highest Sources
of Testing
Concentration
Near top. Sewers, Detectable
Concentrates chemical odor at low
in closed up- feed concentrations
per spaces rooms.
At bottom. Industrial Combustible
wastes, gas indicator
varnish,
solvents.
At bottom An insecti- Combustible
cide gas indicator