|
Hydrogen sulfide is a colorless,
flammable, extremely hazardous gas with a “rotten egg”
smell. It occurs naturally in crude petroleum and natural
gas, and can be produced by the breakdown of organic matter
and human/animal wastes (e.g., sewage). It is heavier than
air and can collect in low-lying and enclosed, poorly
ventilated areas such as basements, manholes, sewer lines
and underground telephone/electrical
vaults.
DETECTION BY SMELL
-
Can be smelled at low levels, but
with continuous low-level exposure or at higher
concentrations you lose your ability to smell the gas
even though it is still present.
-
At high concentrations your
ability to smell the gas can be lost
instantly.
-
DO NOT depend on
your sense of smell for indicating the continuing
presence of this gas or for warning of hazardous
concentrations.
HEALTH EFFECTS
Health effects vary with how long,
and at what level, you are exposed. Asthmatics may be at
greater risk.
-
Low
concentrations – irritation of
eyes, nose, throat, or respiratory system; effects can
be delayed.
-
Moderate
concentrations – more severe
eye and respiratory effects, headache, dizziness,
nausea, coughing, vomiting and difficulty
breathing.
-
High
concentrations – shock,
convulsions, unable to breathe, coma, death; effects
can be extremely rapid (within a few
breaths).
BEFORE ENTERING AREAS WITH POSSIBLE
HYDROGEN SULFIDE
-
The air needs to be tested for
the presence and concentration of hydrogen sulfide by a
qualified person using test equipment. This individual
also determines if fire/explosion precautions are
necessary.
-
If gas is present, the space
should be ventilated.
-
If the gas cannot be removed, use
appropriate respiratory protection and any other
necessary personal protective equipment (PPE), rescue
and communication equipment. Atmospheres containing
high concentrations (greater than 100 ppm) are
considered immediately dangerous to life and health
(IDLH) and a self-contained breathing apparatus (SCBA)
is required.
|
