HYDROGEN SULFIDE
(H2S)
AWARENESS TRAINING
HYDROGEN SULFIDE AWARENESS
(H2S)
Hydrogen sulfide presents a potential hazard
to workers at many work sites.
 occurs as an unwanted by-product
 many different industries or occupations.
 ensure protection against exposure
 be aware of its properties,
 what to do in emergency situations.
HYDROGEN SULFIDE AWARENESS
(H2S)
Hydrogen sulfide is also produced by the
putrefication of organic matter.
It may accumulate in sewers, sewage treatment
plants.
PHYSICAL AND CHEMICAL
CHARACTERISTICS
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highly toxic, poisonous gas
deadly to humans
has no visible color.
It is soluble in hydrocarbons and water at a
ratio of 4: 1,
• highly corrosive to certain metals due to
either hydrogen embrittlement or sulfide
stress cracking.
PHYSICAL AND CHEMICAL
CHARACTERISTICS
• flammable when mixed with air at a
temperature of 500 degrees F,
• lower flammability limit is 4.3% while the upper
flammability limit is 46% by volume in air.
• When ignited, H2S produces Sulfur Dioxide
(SO2) which is extremely hazardous and may
leave victims disabled with pneumonia or
respiratory damage.
PHYSICAL AND CHEMICAL
CHARACTERISTICS
• is 20% heavier than air, and can be
dispersed great distances with only a slight
breeze
• unidentified locations about refineries or
industrial settings could indicate detectable
levels of H2S
• may include low lying areas such as: utility
vaults, pits, ditches, trenches, confined
spaces, inside dikes, or poorly ventilated
areas.
PERSONAL DETECTION
• H2S also known as Rotten-Egg Gas
• or Sour Crude
• can be easily detected due to a strong odor of
rotten eggs, or
• to others, a sweet, offensive, sickening odor
PERSONAL DETECTION
Although it can be detected at a low
concentration of 1 ppm, this early warning
property should not be depended upon as an
accurate indicator of its presence.
Hydrogen sulfide detection by your nose may
not occur as a concentration of this gas
between 100 and 150 ppm can deaden your
sense of smell.
HEALTH EFFECTS
• rapidly-acting systemic poison
• causes respiratory paralysis and asphyxia
• can irritate the eyes and respiratory tract at
low concentrations.
• a concentration greater than 700 ppm,
inhalation may cause coma and/or death after
a single breath.
HEALTH EFFECTS
• Each individual person may be affected
differently by different concentration levels.
• Some individuals are more sensitive.
• If you should smell the presence of H2S or
hear warnings from monitor alarms, then
immediately evacuate this area.
HEALTH EFFECTS
Classed as a chemical asphyxiate
Similar to carbon monoxide and cyanide gases.
Inhibits cellular respiration and uptake of
oxygen, causing biochemical suffocation.
TYPICAL EXPOSURE SYMPTOMS
0 - 10 ppm - Irritation of the eyes, nose and
throat
10 - 50 ppm - Headache, Dizziness, Nausea
and vomiting, Coughing and breathing
difficulty
50 - 200 ppm - Severe respiratory tract irritation,
Eye irritation / acute conjunctivitis, Shock,
Convulsions, Coma, Death in severe cases
TYPICAL EXPOSURE SYMPTOMS
Prolonged exposures at lower levels can lead
to:
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bronchitis,
pneumonia,
migraine headaches,
pulmonary edema, and
loss of motor coordination.
MONITORING
Exposure should be minimized by employing
adequate engineering controls and safe
working practices.
Where engineering controls cannot adequately
control levels of exposure, it may be necessary
to supplement them with the use of suitable
personal protective equipment (PPE) such as
supplied-air respirators.
MONITORING
Identification of hydrogen sulfide
concentrations may require monitoring.
The exposure limit should be set to alarm at a
concentration of 10 ppm.
FIRST AID
First aid needs will depend on the
concentration level
Do not immediately rush to the aid of an
affected coworker unless properly trained and
without protecting yourself with proper PPE.
FIRST AID
Signs and symptoms of an exposure:
• respiratory paralysis by inhalation,
• burning sensation of the eyes due to
contact,
• or skin irritation.
FIRST AID
Inhalation - remove victim to fresh air immediately. If
not breathing, administer mouth-to-mouth artificial
respiration until medical assistance arrives
If breathing is restored but slow and labored,
administer 100% oxygen by canister/mask as H2S is
rapidly detoxified by the body.
Maintain normal body temperature. Transportation to
medical services should follow immediately.
FIRST AID
Eye or skin contact - should be treated by a 15 minute
wash/flush at a safety shower/eye-wash station.
If irritation or discomfort persists, transportation to
medical services should follow immediately.
REFERENCES
Regional poison control center: 1-800-222-1222
Centers for Disease Control and Prevention
Public Response Hotline (CDC)
800-CDC-INFO
888-232-6348 (TTY)
E-mail inquiries: cdcinfo@cdc.gov
Centers for Disease Control and PreventioN (CDC), National
Institute for Occupational Safety and Health (NIOSH), Pocket
Guide to Chemical Hazards