H2S Safety
What is H2S?
H2S has many names such as Hydrogen Sulphide, Sulfuretted (or sulfureted) hydrogen, sulphurated hydrogen; sulfane; sulfur hydride; dihydrogen monosulfide; hydro sulfuric acid; sewer gas; stink damp; rotten egg gas
It is a colorless,
very poisonous, flammable gas with the characteristic foul ardor of rotten
eggs. This is slightly heavier than air and when it leaks, it moves into low
lying areas such as excavations, pits, drains etc. A mixture of H2S and air is
explosive; H2S burns with a blue flame and forms sulfur dioxide (S02) which is
also toxic gas.
How does it Smell?
Smells like rotten eggs when in low concentration but when the H2S gas is in high concentration, it is ability to kill the sense of smell of human beings even breathed for longer periods at low concentrations. It kills your sense of smell.
Properties of H2S
Highly Toxic
Smells like rotten
eggs when in low concentrations but when in high concentration it has ability
to kill the sense of smell of human beings.
Colorless, you
cannot see it.
Highly Flammable
A mixture of air
and H2S is explosive.
Slightly heavier
than air, settles in low lying areas.
Soluble in water,
it mixes in water.
The Role of Machine Guarding in Workplace Safety
Permissible Exposure Limit
In Oil and Gas
Industry, It is not allowed to work in presence of H2S gas, engineering
controls shall be applied to remove and make the area gas free before starting
the work. If hazard persists, then BA shall be used along with other controls. However,
industry has set the following limits:
Long term exposure
limit (LTEL) is at 10 ppm for 8 hours a day, 5days a week. If a person works 8
hours a day 5 days a week in 10 ppm of H2S, he shall not have serious affects.
Short term
exposure limit (STEL) is at 15 ppm; A person can only work for 1 hour if the
gas concentration is 15 ppm.
PPM stands for Parts Per Million
Is H2S Flammable /Toxic
Both, H2S is
extremely toxic gas; It can kill people immediately if exposed to high
concentration of this gas.H2S gas is highly flammable and toxic.
Office Safety | Housekeeping | Napo
How would you protect yourself from H2S?
Following
precautions shall be taken to work in areas where H2S can be present:
Tolerate to enter
in areas where H2S concentration is detected and is at or exceeding STEL (15
ppm and above)
You should have
H2S training.
Get Permit
Perform gas test
and ensure that H2S or any other hazardous gas is not present in your work area.
Confined spaces
shall be properly ventilated before entry; ventilation shall continue until the
space is cleared by persons.
If entering a confined
space, spading and de-spading, you shall use breathing apparatus if identified
and specified in the permit and TRA for the job.
Know the location
of your muster Point and be aware of the wind direction.
Never depend up on
your nose to detect H2S.
Always keep handheld
gas detector in confined spaces and in most H2S potential areas.
The Importance of Ergonomics in the Workplace