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Hydrogen Sulfide Safety Training To Meet API-RP- 49 & 55 Requirements
10th
Edition
Hydrogen Sulphide Safety Training Course
10th
Edition
Meets API-RP 49 & 55 Requirements
Intended for: All personnel working offshore or onshore where the presence of Hydrogen
Sulfide is known or suspected.
Content: A. Introduction and Registration
B. Aims and Objectives
C. Sources of H2S
D. Chemical Properties of H2S and SO2
E. Hazards of H2S, Symptoms of Exposure F. Respiratory Protection
G. Monitoring & Detection
H. Safety Procedures & Contingency Plan
I. Rescue Techniques - basic
J. Donning and Doffing of SCBA
K. Connection of the SCBA to the cascade system
L. Written Test
As English is the predominant language used during emergencies, the attendees must be
able to understand spoken English. It is the responsibility of the sponsoring company to
ensure that the attendee is physically fit.
Aim: To give persons the necessary skills to respond correctly and safely in the event of
H2S gas release.
Objectives: Upon completion of this course, the attendee should be able to:
1. Describe the physical properties and hazards of H2S and SO2.
2. Show an understanding of proper work procedures while working in the presence of H2S. 3. Show an understanding of H2S detection and monitoring. 4. Show an understanding of the contingency plan.
5. Show an understanding of rescue plan in an H2S environment.
6. Safely don and start up Self-Contained Breathing Apparatus.
7. Demonstrate the proper procedure for attaching to the cascade system via the
hose line connection.
8. Pass a written test.
Sources of H2S Where does Hydrogen Sulfide come from?
H2S is an extremely toxic gas that is formed by decomposing organic material. Organic material
can be comprised of plant or animal matter. Actually, the same process that provides us with
oil, sometimes gives us unwanted H2S. H2S is not strictly a problem associated only with the
oil & gas industry. It can be found in many other industries, also. You might encounter H2S
in:
Sewers Paper Mills
Septic Tanks Chemical Factories
Mines Tanneries
Several industries use hydrogen sulfide as an industrial chemical, such as heavy water producers
and pulp mills. However, most hydrogen sulfide is a waste or by-product encountered during
other operations.
Hydrogen Sulfide goes by many different names. Because of its distinctive foul odor at low
concentrations, these names include:
Rotten Egg Gas H2S
Sour Crude Swamp Gas
Sulfurated Hydrogen Stink Damp
Hydrosulfuric Acid Dihydrogen Sulfide
It must be stressed at this time that you can not depend on this odor in the detection of hydrogen
sulfide. H2S is a very sly gas that causes very few physical effects until hazardous
concentrations have been reached. When dangerous concentrations of hydrogen sulfide are
encountered, one of the first effects of this gas is on the sense of smell. At concentrations as low
as 10 ppm, the olfactory nerve becomes paralyzed in a very short time and the gas cannot be
detected by the nose.
Chemical Properties of H2S and SO2
We have briefly discussed the problem we have with H2S because it’s characteristic of
deadening our sense of smell. Let’s discuss some of the other properties of H2S. Hydrogen
Sulfide belongs to the Inorganic Sulfide family of Chemicals. The chemical formula is H2S or
2 parts hydrogen and 1 part sulfur. You would normally find H2S in a gaseous state, as its
melting point (where a solid turns into a liquid) is -85° C or – 121° F, and its boiling point
(where a liquid turns into a gas) is -60° C or -76° F.
The physical properties of H2S that we will be discussing
are:
1. Toxicity
2. Color
3. Odor
4. Density
5. Boiling Point
6. Flammability
7. Solubility
8. Corrosiveness
1. Toxicity We have said that hydrogen sulfide is a toxic gas. This means that this gas can be deadly.
One term we use for this gas is Immediately Dangerous to Life and Health, or I. D. L. H.
When we discuss the toxicity of H2S, we will use the term ppm or Parts per Million.
Incidentally, does everyone here understand what we mean by part per million? If we say
one part per million we are saying that we have one molecule of hydrogen sulfide mixed in one
million molecules of breathing air, by volume.
Another way of looking at this is:
One second in 11 ½ days, one inch in 15 ½ miles in distance, or 2.5 centimeters in 24.5
Kilometers.
One Per Cent of H2S by volume in the atmosphere equals 10,000 parts per million.
We can smell Hydrogen sulfide in quantities as little as one ppm. H2S can kill you in quantities
as little as 700 ppm.
2. Color The best way to show the color of H2S is this; take a deep breath and hold it for three
seconds. Now breathe into your hands. H2S is the same color as that breath. Colorless! You
cannot see H2S. This is one of the reasons it is so dangerous, it’s the Invisible Killer.
3. Odor We stated earlier that H2S smells like rotten eggs in low quantities. This is another reason
why this gas is so deadly. When the quantity of H2S reaches the levels where it is harmful to
the human body, it has no odor. YOU CANNOT DEPEND ON THE SENSE OF SMELL
TO DETECT H2S. Whenever you smell H2S and the odor goes away, it is easy to believe
that the gas has gone away. This is the wrong assumption, because the quantity of H2S might
have risen to the level where your olfactory nerves have been deadened. Remember when
you assume, you make an ass out of you and me! Assume = ASS / U / ME
4. Density When we speak of density we are talking about the weight of the gas. You might think that it is
very light. But we are talking about its weight as compared to the ambient air. (Ambient means
the free air in the atmosphere around you.) Hydrogen Sulfide is heavier than air. If the air
around you has a specific gravity of 1, then H2S has a specific gravity of 1.189.
This is one of the characteristics of H2S that we use to our advantage. H2S is heavier
than air so it will travel with the wind. When there is no wind it will tend to find the lowest point
possible to settle in. So if we know the wind direction, we can determine where the gas will spread.
WARNING!! Even though this gas is heavier than air, there are still some reasons why it
will not always immediately settle. If the gas is warmer than the surrounding air, it will tend
to rise. If the gas is under pressure, it will go wherever the pressure directs it. Hydrogen Sulfide is easily diluted by air movement because the volume of air to H2S
changes more rapidly than it would in still air. We use the wind direction to our advantage,
so knowing the wind direction is very important to us. We can detect wind direction by use of:
1. Wind Socks
2. Streamers
3. Flags
4. Smoke from the flare stack
WIND DIRECTION
You should move upwind. H2S
You must always remember to move upwind or crosswind (if you cannot move upwind due
to circumstances). Breathing apparatus, detection equipment, and the safe briefing areas are
placed with prevailing wind direction in mind. Wind direction and movement can be your
best friend when dealing with H2S. Because H2S is heavier than air, it has a tendency to “Stack” or displace air to higher levels
in areas of poor ventilation. This is the reason we use artificial ventilation or “Bug-Blowers” in
areas where wind movement might be non-existent, or if we are trying to move the gas away
from our work area.
ALWAYS BE AWARE OF WIND DIRECTION. H2S WILL MOVE WITH THE WIND
AND TEND TO COLLECT IN LOWER AREAS.
5. Boiling Point Hydrogen Sulfide has a boiling point of – 76° Fahrenheit or – 60° Centigrade. Why do we
mention this? This is a significant fact because this means that under all circumstances in
which we will encounter H2S it will be in a gaseous form. When a liquid boils, it produces gas
or vapor.
6. Flammability Hydrogen Sulfide is a highly flammable gas with an LEL (Lower Explosive Limit) of 4.3 %,
(43,000 ppm) at sea level, and UEL (Upper Explosive Limit) of 46 %, (460,000 ppm) by
volume. The auto ignition temperature is approximately 500° F or 260° C. (Auto ignition
means the temperature where the gas will ignite without a spark, arc, or flame.)
Once the temperature has reached the auto-ignition temperature and gas is within the explosive
limits or burn range, hydrogen sulfide will ignite. H2S burns with a bright blue flame and
produces sulphur dioxide, or SO2.
Sulphur Dioxide is also a toxic gas. It is even heavier than Hydrogen sulfide with a specific
gravity of 2.264 by volume. SO2 has no color but does have a pungent odor that gives ample
warning of its presence. The threshold limit value for SO2 is 2 ppm, and is immediately
dangerous to life at a concentration of 500 ppm. Throat irritation, coughing, and tearing are side
effects of SO2 exposure. Studies have shown that prolonged or repeated exposure to SO2
without breathing protection can scar tissues in the lungs.
At this point you might be asking yourself, “Why do we burn a dangerous gas to protect
ourselves, when by burning it we produce a more dangerous gas which can kill us even
quicker?” This is a good question. The answer is that, as explained earlier, one of the ways to
get gas to rise initially is to ensure that it is hotter than the ambient air. By flaring the H2S,
producing SO2, we allow the gas to rise, and move away from the rig with the wind. As the gas
cools, it will drop to the lowest point. This is the reason we only flare gas so that it moves
with the wind and away from the rig. We do not flare gas when there is no wind movement
because the gas would fall back on to the rigs.
6. Solubility Hydrogen Sulfide is soluble in water. At 32° Fahrenheit (0° Centigrade) 4 parts of gas can be
retained in 1 part water, at 68° F, (20° C), 2.6 parts of gas will be retained in 1 part of water,
volumetrically. What this means to us is that the gas, H2S, can come up the drill string and be
dissolved in the mud without being detected by gas sensors. Please Note: H2S is also soluble
in oil. However, as the temperature of the oil increases, the solubility of the H2S gas increases.
There are several ways that this gas can be released from the mud.
1. Temperature change.
2. Pressure change.
3. Agitation by the shale shakers, degasser, or mud pits.
4. PH change.
7. Corrosiveness H2S is a corrosive gas. It reacts with metals, plastics, rubber, tissues, and nerves. H2S
reaction with some metals results in an effect known as Hydrogen Sulfide stress cracking.
This is a result of metals being subjected to high stress levels in a corrosive environment where
H2S is present. H2S dissolves in water to form a weak acid that can cause some pitting
in the presence of oxygen and/or carbon dioxide. The most significant action of H2S is its ability
to form hydrogen embrittlement. The harder the steel, the greater sensitivity to sulfide stress
cracking. This is the reason that great care is taken when determining which materials are to
be used when designing the drill string to be used when H2S presence is expected.
For the purpose of this course we will not get deeper into the corrosive nature of Hydrogen
Sulfide. The important thing to remember is that this gas can cause serious damage to the
metal used in drilling and production, as well as the seals used to keep the fluids and
pressures within the system. A preventative maintenance program should be maintained so
that the equipment is protected as much as possible in an H2S environment so that equipment
failure can be kept at a minimum.
Hazards and Symptoms of H2S Exposure
When a person breathes in H2S it goes directly through the lungs and into the bloodstream. For
protection, the body "oxidizes" (breaks down) the H2S as rapidly as possible into a harmless
compound. If the individual breathes in so much H2S that the body can't oxidize it
all, the H2S will build up in the blood and the individual becomes poisoned.
The nerve centers in the brain that control breathing become paralyzed. The lungs stop working
and the person is asphyxiated.
The way H2S affects you depends on the following factors:
1. Duration: The length of time you are exposed.
2. Frequency: How often you are exposed.
3. Intensity: The concentration to which you are exposed.
4. Individual Susceptibility: Your physiological make-up.
It is worth mentioning that persons who have consumed alcohol within 24 hours of exposure
have been overcome by unusually small concentrations of H2S. H2S and Alcohol
consumption DO NOT MIX. Research studies show that symptoms of H2S exposure vary considerable because of individual
physiological make-up. Some industrial studies indicate that persons previously exposed to
H2S tend to be hyper-susceptible to the gas rather than build up a tolerance. Other studies
indicate that previous exposure has no effect either way. Without conclusive proof, we must
consider those previously exposed as hypersensitive to H2S.
Low Concentrations Symptoms of Exposure
Irritation to the eyes, nose, and throat
Moderate Concentrations
Excitement
Headache
Dizziness
Nausea
Vomiting and coughing
Loss of Equilibrium
Pulmonary Adema (chemical pneumonia)
High Concentrations Rapid loss of consciousness
DEATH
TOXIC EFFECTS OF HYDROGEN SULFIDE
PPM PHYSICAL EFFECTS/EXPOSURE LIMITS .013 Lower odor threshold – detectable rotten egg odor
4.6 Obvious odor of rotten eggs
10 Possible headache – PEL (permissible exposure limit) OSHA
15 Mild nausea – STEL (short term exposure limit) allowable for 15 min. OSHA
20 Possible fatigue – TLV Ceiling (ACGIH)
27 Upper odor threshold – very strong odor
50 Drowsiness – TLV Peak (ACGIH)
100 Loss of sense of smell in 2-15 minutes – dryness in eyes, nose and throat
200 Burning sensation in eyes, nose, throat and chest; rapid loss of sense of smell;
Stiffness in joints
300 Immediately dangerous to life or health – IDLH level
500 Loss of equilibrium; loss of mental function; respiratory disturbance
750 Rapid unconsciousness, followed by respiratory arrest
When considering working in an H2S environment you must be aware that your
capacity to tolerate exposure to this gas can be reduced by several special health problems.
Some of the physical limitations that can impair your ability to work in an H2S environment
are:
1. Emphysema
2. Chronic Pulmonary Obstructive disease or Bronchial Asthma
3. Progressive or Severe Hypertension
4. Diabetes
5. Anemia
6. Alcoholism
7. Smoking tobacco products
8. Physical condition or age factors.
The target organs of H2S poisoning are the olfactory nerves, lungs, brain, respiratory control
center and the eyes. When hydrogen sulfide combines with water, a sulfurous acid is produced.
This is why you feel a burning sensation in your eyes when exposed. You will experience a
burning sensation in your nose, throat and lungs because of the presence of water in the
mucous membranes.
Respiratory Protection One of our greatest weapons in dealing with an outbreak of Hydrogen Sulfide is the use of
breathing apparatus. However, there are several problems to consider if we are to utilize this
equipment to its full potential.
Special Problems in Respirator Use
1. Facial Hair:
Facial hair between the sealing surface of the respirator facemask and the wearer's
skin will prevent an effective seal. Even one day's growth of stubble can permit
excessive contaminant penetration.
2. Contact Lens:
Contact lens are a definite hazard and should not be worn while wearing a respirator
in an H2S environment.
3. Corrective Spectacles:
Glasses with temple bars or straps that interfere with the respirator face seal should
not be worn.
4. Psychological Disturbances:
Psychological problems, such as claustrophobia, are a definite hazard to the wearer of
a respirator.
5. Miscellaneous Sealing Problems:
Sealing problems vary according to the individual. The most noticeable ones are
scars, hollow temples, very prominent cheekbones, deep scar creases, lack of teeth, or dentures.
5. Discomfort:
Any person wearing a breathing apparatus will experience some discomfort because
breathing is more difficult and vision, movement and communication are restricted.
The only way to determine whether or not an individual can wear a breathing apparatus
safely is to perform a fit test on the individual, and allow them to don the apparatus to
experience the awkwardness firsthand. Only through training and familiarization can the
discomforts of wearing a breathing apparatus be reduced to a minimum.
Self Contained Breathing Apparatus
There are three basic types of self-contained breathing apparatus (SCBA):
1 Rescue Unit 2. Work Unit 3. Escape Unit
Escape Units
Escape units are designed to be quickly and easily donned in an emergency situation. They
usually have from between five and fifteen minutes of air in a self-contained storage cylinder
and are designed for escape purposes only. An escape unit cannot be used to effect a rescue
or to accomplish any task other than evacuation of a hazard zone. Ordinarily an escape unit does
not have a warning alarm to alert the wearer of low air supply. This unit is of limited air
supply and must not be worn to approach a hazardous area.
Escape/Work Units This is a combination escape unit and supplied air respirator (SAR) that can be connected to a
remote air supply for extended use. The supply airline used with this type of unit can be up to
250 ft. in length. The air cylinder used with this device should have 15 minutes of air to be used
upon failure of the remote air supply or when evacuating the work area. Once the escape
cylinder is turned on the breathing air unit is to be considered the same as an escape unit and
cannot be used to reenter the hazardous area. DO NOT open the escape cylinder valve while
you are still plugged into the remote air supply as you may bleed down the emergency air
supply before you need it. Bear in mind that the pressure inside the air cylinder is between
2,000 and 3,000 psi and that the pressure inside the air hose is 100 psi. If both are open at the
same time, the pressures will equalize, thus using up your emergency escape air supply leaving
you no chance of escape if necessary. As with the escape units, the escape/work unit has no low
pressure warning whistle or bell, so once the escape bottle is utilized, you must evacuate the
hazardous area as quickly as is safety possible.
Rescue Units Rescue units are normally thirty (30) minute back packs designed for use as a rescue unit or
as a working unit. However, with newer technology and use of lightweight materials, you
will find many 45 minute or 60 minute units in operation. Often the rescue unit is equipped with
an airline connection for use with a remote air source. As these units are designed to enter a
hazardous area for work or rescue purposes, they will have a low pressure alarm which
activates when the pressure in the cylinder drops to a level of about 500-700 psi or five to seven
minutes. Once this alarm bell or whistle activates, this unit is to be treated as though it were an
escape unit. EVACUATE the area immediately.
There are several factors to be considered when furnishing people with safe breathing air:
1. That the air is of acceptable quality. (Get copies of the certificate showing grade
of air and the date compressor unit was last certified).
2. Adequate amount - in most cases it is always better to have more breathing air
readily available than is needed.
1. Quality
The air supplied by the air compressor must meet the standards set forth by various certifying
bodies as grade "D". To meet these standards, the air compressor must purify the air produced
to contain the following:
Water Vapor (Should be </=50 Mg/M3)
Carbon Monoxide (Should be </=10 ppm)
Carbon Dioxide (Should be </=500 ppm)
Oil Mist (Should be </= .5 Mg/M3)
2. Amount
In reality, each man should be trained and drilled to determine his own duration by using self-
contained breathing apparatus under extremely strenuous working conditions. Since this is
usually not possible, we have taken the NIOSH (National Institute of Safety and Health)
which determines the rated duration in their testing at medium heavy work. So, if a breathing
apparatus has been rated as a 15 minute breathing apparatus, a person in good health should
be able to breathe on the unit for a minimum of 15 minutes under most conditions. To ensure
safety, we advise that a safety factor of 30 % be used to ensure that the person does not run
out of air. This would mean that you should be able to evacuate the danger zone within
approximately 10 to 11 minutes while using a 15-minute unit.
We use the following in determining air quantity:
Decimal System Metric System
One Cubic Foot = 28.3 Liters
30 minute Cylinder (45 Cubic Feet) = 1,273.5 Liters
300 C. F. Cylinder (in Cascade System) = 8,490 Liters by Volume
6 Cylinder Cascade Rack (1,800 C. F.) = 50,940 Liters by Volume
What does this mean in reality? • One man at Medium Work breathes approx. 1.5 Cubic Feet (40 liters) of air per min.
• One man at Maximum Work breathes approx. 4.6 Cubic Feet (131 liters) of air p/m.
Compressed
Breathing Air
Grade "D"
ONE MAN
Medium Work
Conditions
ONE MAN
Maximum
Work Conditions
SIX MAN
Medium Work
Conditions
SIX MAN
Maximum
Work
Conditions
One (1) Cylinder
300 Cubic Foot
Approximate
Consumption Rate
3 hrs.33 min.
Approximate
Consumption Rate
1 hr.
Approximate
Consumption Rate
33 min.
Approximate
Consumption
Rate
10 min.
Detection & Monitoring
The detection and monitoring of Hydrogen Sulfide in the work place is essential to
implementing a personnel safety program. No human sense can be relied on as a means of
detecting H2S. Emphasis on this effect is warranted due to the rotten egg odor of low
concentrations of the gas. A false sense of security may result when the rotten egg odor is at
first present and then seemingly disappears. The situation could be that:
A. The gas has dissipated.
B. The gas has increased and the sense of smell has been lost.
Until the area has been tested for H2S with a reliable H2S gas detection device, you
must assume that situation (B) above is in effect.
Detection and Monitoring Equipment
There are two basic types of detection devices available, electronic monitors and chemical
detectors. Both types of equipment have their advantages and disadvantages.
Chemical Detectors
Chemical detectors generally utilize lead acetate or cupric sulfate as an agent to react with
H2S to produce a stain on paper tape or on silica gel granules. The normal color change is
from white to brown. When using a color metric tube type detection device, suction is applied
to a tube by means of a mechanical pump in order to pull an ambient air sample through the
tube. Any H2S gas in the sample will result in a discoloration of the tube. Most color metric
tubes are direct reading.
Advantages
1. No power source necessary.
2. Relatively inexpensive.
3. No calibration is needed.
4. High degree of accuracy.
5. Wide range of measurement.
Disadvantages
1. No alarms.
2. Non-continuous monitoring must be done periodically.
3. Require manual operation.
4. Limited remote sampling capability.
Electronic Monitors
These devices can be fixed, solid-state, continuous monitoring systems with remote sensing
capabilities utilizing several remote sensing heads, or they can be single channel hand-held
portable units with one sensing head. Both work on the same principles.
Advantages
1. Quick reaction to gas.
2. Automatically actuated alarms.
3. Remote sensing capabilities.
4. Multiple gas sensors (fixed systems)
5. Continuous monitoring.
6. Capable of storing information to be downloaded at future times.
Disadvantages
1. Non-analytical. Maximum readout usually 99 ppm or less.
2. Very expensive, $ 600.00 to $ 1,500.00 per channel.
3. Moisture sensitive. Excess water can short out the sensor temporarily.
4. Sensors must be periodically exposed to H2S or they become sluggish.
As stated above, two of the advantages of an electronic multiple head fixed monitoring
system is its ability to monitor for gas in several locations simultaneously and automatically
actuated alarms.
Federal regulations in the United States have set certain limits for the amount of H2S to which
a worker can be exposed. These are referred to as Threshold Limit Values, or TLV. These values are listed as:
TLV-TWA (Time Weighted Average): are used when figuring average concentrations
for a normal 8-hour day or 40-hour work week of which nearly all workers may be repeatedly
exposed without adverse effects. For H2S, it is 10 ppm.
TLV-STEL (Short Term Exposure Limit): are used when calculating the maximum concentration to which a worker can be exposed for a period of up to 15 minutes continuously
without suffering any ill effects which would increase accident proneness, impair self rescue,
etc. For H2S, it is 15 ppm.
TLV-C (Ceiling): are used when the concentrations should not be exceeded, even for
an instant. For H2S, it is 20 ppm.
The alarms can be set to actuate at any desired level. Usually the alarm points are set at the
following levels:
Low Alarm set to actuate at 10 ppm. The low alarm is usually connected to a series
of flashing lights that are located in living areas or work areas.
This corresponds to the Time Weighted Average (TWA) level set by OSHA.
High Alarm set to actuate at 15 or 20 ppm. The high alarm is usually connected to a
series of sirens that are located in the living areas or work areas.
This corresponds to the Short Term Exposure Limit (STEL) at 15 ppm or The
Acceptable Ceiling Concentration as set forth by OSHA, 20 ppm. Once the alarms
have been set, they will automatically actuate whenever any of the remote monitor heads
come in contact with H2S that exceeds the level set.
Safety Procedures & Contingency Plan Each location will have its own contingency plan, which will be written specifically for that
location and scope of operations. These plans and procedures should be posted so that all
personnel on location will know what is expected of the event of an H2S emergency. It is the
employer's responsibility to post these procedures. HOWEVER, it is the employee's
responsibility to become familiar with these procedures and understand them.
In all instances, the normal response to an emergency H2S situation without any prior warnings
(e. g., sudden gas leak, gas in the mud, H2S warning siren), the procedures should be:
1. Hold your breath and don breathing equipment if available.
2. Move upwind of the leak. Note wind direction.
3. Evacuate quickly to the "Safe briefing Area".
4. Alert all persons on your way to the briefing area who haven’t heard the alarms.
5. Report to the supervisor in charge of the safe area.
6. Await further instructions.
7. DO NOT PANIC.
As stated above, no two locations are the same. Even though you may have worked on
similar operations there will be something different to take into consideration. Some of the
differences you might encounter could be:
1. Personnel
a. experience of crew
b. language problems, different nationalities
c. number of personnel on location
2. Physical Location
a. Age of structure
b. Age of equipment
c. Escape routes
d. Living accommodations
3. Safety equipment used
a. Type of breathing apparatus
b. Monitoring equipment
c. Medical personnel, or lack of medical personnel
d. Lifesaving equipment, i.e. Lifeboats, capsules, etc.
4. Emergency response plan in effect
a. Station bill
b. Responsibilities
Remember, it is up to you to understand the safety policies in your place of work, whether it
is on an offshore drilling rig, production platform, ship, or other location where you might come
across H2S. The first question you should ask when arriving on an offshore facility is, "How do
I get off this location if something happened right now?" You will probably be met as soon as
you arrive at the facility. You will be given a safety lecture explaining the safety policies and
procedures. Please, if you do not understand ask question. Remember, "There is only stupid
question; the one you didn't ask."
Rescue Techniques - (Basic) When the effects of Hydrogen Sulfide gas overcome an individual, TIME becomes on of the
most important elements in executing a rescue. The H2S victim must be removed to an
uncontaminated area and resuscitated as soon as it becomes feasible to do so.
When a suspected H2S gas victim is located, an alarm should be sounded to alert other personnel
of the fact. By sounding the alarm, support teams can be formed, with proper back-up
equipment, such as a stretcher and resuscitator, made ready. Air-vac or medivac plans can be
implemented without unnecessary delay.
Before we can perform an effective rescue, we must be assured of two things that will make the
operation both safe and successful.
1. We must have sufficient manpower to complete the rescue attempt.
If an attempt to rescue the victim is made without proper backup personnel the attempt could
seal the fate of the downed victim. The buddy system should always be in effect whenever
we are in an unknown or suspected H2S contaminated area. Avoid attempting a Solo rescue
as it is extremely difficult to manipulate an unconscious person alone, especially when restricted
by a breathing apparatus.
2. We must have sufficient air supply to perform the rescue safely for the rescuers.
Remember that you must put on your breathing apparatus before attempting a rescue.
Regulations require that a rescuer's air supply should be sufficient to enter a contaminated
area, complete the task (the rescue) and exit the contaminated area. This effectively eliminates
the possibility of attempting a rescue with anything other than a rescue type breathing apparatus.
Once you have established the two criteria above, you may proceed with the rescue attempt.
You are now in a position to retrieve the victim and remove him to fresh air. It is necessary
to remove the victim UPWIND from the source of the release of the H2S gas. You should
move the victim only as far as necessary to insure his safety and yours.
When you have settled upon a safe upwind position it will be necessary to remove your
respirator in order to evaluate the victim, your patient. One of your buddies should remain
with you to monitor wind direction. Should the wind shift, endangering your safety, your
buddy can immediately inform you so that you can protect yourself.
Again, NEVER work alone. “Use the Buddy System”
First Aid Once the patient is rescued and you are both in a safe upwind position, priority of care must
be established.
First priority of care is the continuing safety of the rescuer. As stated earlier, you need to
have a "buddy" with you to monitor wind direction and assist you in moving the patient if
necessary.
After your "buddy" has given the all-clear signal that there is no H2S present, you can
remove your mask to begin assessment of the patient. If at all possible, use barriers to protect
yourself against contaminated fluids. (i.e., gloves and one way mouth-to-mouth barrier)
Primary Assessment Check Sheet
1. Tap and shout. If no response,
2. Open Airway (try to protect the spine as much as possible).
3. Look, listen, and feel. Watch for chest movement, listen for breath, and feel for breath on
your cheek. IS HE BREATHING? If not, begin mouth-to-mouth breathing.
4. Check carotid pulse. IS THERE A PULSE? If not, begin chest compressions.
5. Check for and control serious bleeding.
6. Treat for shock. Keep warm, and elevate feet 8-10 inches, if no spinal injury is suspected
7. Monitor vital signs until medical help arrives.
Mouth to Mouth Resuscitation
The patient must not be left alone. Even patients who appear to be breathing normally can
go into shock at a moment's notice. Also, remember that one of the greatest
hazards from H2S poisoning is pulmonary edema (chemical pneumonia). The victim's
lungs fill up with water. Any time a person has been overcome by H2S poisoning, he must be
checked by a doctor to ensure that there is no lingering after effects. Only a doctor can give the
patient a clean bill of health.
Donning Procedure
Donning and Doffing of SCBA 1. Open the case.
2. Turn the Cylinder on
Slowly open the cylinder valve in a counter clockwise direction. The alarm whistle will
activate as the breathing system pressures up.
3. Check Demand Valve
Check demand valve to ensure that the red bypass knob is in the “OFF” position, and depress
black reset button. Check the pressure gauge to ensure that the cylinder is full.
4. Don Apparatus
With shoulder straps and waist belt fully slackened, don apparatus using the “coat” method. One
arm through the shoulder straps, swing apparatus behind you, then put other arm through the
other shoulder strap. Adjust straps for a comfortable fit and secure waist belt.
5. Don Mask
With head straps fully slackened, place chin into chin-cup and pull harness straps over back
of head, ensuring that the straps are not twisted and no hair is trapped under the face seal.
Tighten straps in sequence, BOTTOM, MIDDLE, TOP. Inhale sharply to activate the first
breath mechanism, breathe normally. Insert finger under face seal and check for steady flow
outward. Remove finger and allow facemask to reseal.
6. Recheck Check Bypass/Cylinder Pressure
Turn bypass on demand valve and check for steady flow of air. Close on completion. With
cylinder valve fully open; check pressure gauge to ensure that sufficient air is remaining for
anticipated tasks.
The question, “How fast is fast enough?” always comes up when people are discussing the
length of time needed to put on a breathing apparatus. I answer this question with another
question, “How long can you hold your breath?”
You should be able to don the breathing apparatus after the alarms have been sounded
without taking another breath.
Doffing Instructions
Do not remove breathing apparatus until you are in a SAFE area, free of hazards. 1. Reset Demand Valve
Take a deep breath and depress reset button on demand valve.
2. Remove Facemask
Pull metal tabs on buckles to slacken the head harness. Remove facemask and let hang from
strap around neck.
3. Remove Apparatus
Release waist belt, slacken shoulder straps and remove the apparatus, making sure that the
regulator is protected from accidental damage.
Remember, all straps should be re-extended after use. As soon as the facemask is removed,
lengthen the holding straps so that the mask is ready to re-don in case alarms are
reactivated.
Connection of the SCBA to the Cascade System The supply airline used with this type of unit can be up to 250 ft. in length. The air cylinder
used with this device may have from between five and fifteen minutes of air and is to be used
upon failure of the remote air supply or when evacuating the work area.
Once the escape cylinder is turned on the breathing air unit is to be considered the same as an
escape unit and cannot be used to reenter the hazardous area. DO NOT open the escape
cylinder valve while you are still plugged into the remote air supply as you may bleed down
the emergency air supply before you need it. Bear in mind that the pressure inside the air
cylinder is between 2,000 and 3,000 psi and that the pressure inside the air hose is 100 psi. If
both are open at the same time, the pressures will equalize, thus using up your emergency escape
air supply leaving you no chance of escape if necessary. As with the escape units, the
escape/work unit has no low pressure warning whistle or bell, so once the escape bottle is
utilized, you must evacuate the hazardous area as quickly as is safely possible.
Kish Abdal Industrial projects Management Co.
Address: Block 76-77, Naft St., NoAvaran Sq., Industrial Phase 3, Kish Island, Iran
Tel: (+98764)-4450346,(+98764)-9314921
Fax: (+98764)-9317033
Email: [email protected]