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H2S PROTECTION
NPC TRAINING PROGRAM
COURSE MATERIALS
Presented by Sean Massier
H2S PROTECTION S.E.A.L. International
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Table of Contents H2S PROTECTION.......................................................................................................... 1
COURSE OBJECTIVE ......................................................................................................... 1
HYDROGEN SULPHIDE ............................................................................................... 3 PROPERTIES OF H2S ......................................................................................................... 3 HOW H2S FORMS.............................................................................................................. 3 LOCATIONS IN THE OIL AND GAS INDUSTRY.................................................................... 4 MEASURING IN % AND PPM.............................................................................................. 4 OCCUPATIONAL EXPOSURE LIMITS (OEL)....................................................................... 4
EFFECTS ON HUMAN BODY ...................................................................................... 5 LUNG ACTION .................................................................................................................. 5 ACIDITY OF H2S IN SOLUTION .......................................................................................... 5 H2S TOXICITY TABLES...................................................................................................... 5
PERSONAL PROTECTION........................................................................................... 7 DIFFERENT APPLICATIONS............................................................................................... 7 ADVANTAGES AND DISADVANTAGES .............................................................................. 7 FACTORS AFFECTING AIR CONSUMPTION.......................................................................... 7 COMPONENTS OF SCBA .................................................................................................. 8 COMPONENTS OF SABA................................................................................................ 10 CASCADE STORAGE CYLINDERS AND REGULATORS ...................................................... 11 DEMONSTRATION........................................................................................................... 11 ESCAPE CYLINDER......................................................................................................... 12 SCBA / SABA............................................................................................................... 13 PRE-USE INSPECTION CHECKLIST FOR SCBA................................................................ 14 PRE-USE INSPECTION CHECKLIST FOR SABA................................................................ 15 CLEANING, INSPECTION AND STORAGE.......................................................................... 16
RESCUE .......................................................................................................................... 17 TECHNIQUES FOR LIFTING AND CARRYING VICTIM TO SAFE AREA .................................. 18 RESCUE BREATHING AND CARDIO PULMONARY RESUSCITATION (CPR)....................... 21 MEDICAL ATTENTION .................................................................................................... 23
DETECTION AND MONITORING ............................................................................ 25
ELECTRONIC H2S MONITORS ......................................................................................... 25 TUBE TYPES – BELLOWS AND PISTON ............................................................................ 29 INSTRUCTOR’S DEMONSTRATION................................................................................... 32 MULTIGAS MONITOR - LOWER EXPLOSIVE LIMIT (LEL) ............................................... 33 SO2 MONITORS .............................................................................................................. 34
CLASSROOM CASE STUDIES................................................................................... 35
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Course Objective
The objectives for this course:
• The S.E.A.L. International Hydrogen Sulphide (H2S) Protection course is
designed for oilfield personnel who have little or no formal H2S training.
• Ensure you know what to do when H2S is present.
• Protect yourself from the dangers of H2S.
All topics within this training course are dealt with in general terms for ease of
understanding. However, full technical details are available to personnel who want or
need to know them. The format of S.E.A.L. International’s H2S Protection course is such
that it is completed in 6 to 8 hours.
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Properties of H2S
• usually found as a gas
• colourless
• smells like rotten eggs
• specific gravity
heavier than air
gravitates towards low lying areas
influenced by wind direction
• solubility
dissolves easily in water and oil as well as most other fluids commonly
used in the oil and gas industry
• flammable
burns with a blue flame
• explosive in certain ranges
• burning H2S to create sulphur dioxide (SO2)
properties of SO2 gas
• direction
How H2S forms
• Rotting plant and animal matter
Found in sewage treatment facilities, animal barns (manure), and chemical
processing plants.
• Associated with hydrocarbons
Oil and gas are formed by decaying plant and animal matter from millions
of years ago.
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Locations in the Oil and Gas Industry
• drilling mud returns (shale shaker, bell nipple)
• flow lines
• flare pits
• production tanks and facilities
• cement and spent acid returns
• hydraulic fracturing fluid returns
Measuring in % and ppm
• The relative size of 1 ppm
Let’s take, for example, the 1,000-kilometre distance between Tehran and
Robat Sharat (close to Mashhad). One (1) part per million of that distance
is one (1) metre, or a long step.
• ppm expressed as a percentage (10,000 ppm = 1%)
1% = 10,000 ppm
one tenth of 10,000 ppm = 1,000 ppm
one tenth of 1% (1,000 ppm) is more than enough to kill you
ideal working condition is 0%
Occupational Exposure Limits (OEL)
• Recommended exposure limits
10 ppm – maximum allowable for 8-hour period
15 ppm – maximum allowable exposure for 15 minute period with 60
minute space between exposures
20 ppm – maximum exposure limit – must wear breathing apparatus
best industry practice – 0 ppm exposure
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Lung action
• Oxygen (O2) – carbon dioxide (CO2) exchange.
• H2S molecules easily enter system via lungs and blood flow.
• Interrupts breathing control centre in brain.
• Breathing stops, heart stops, no oxygen goes to brain.
• Lack of oxygen causes death.
• Pulmonary edema. After exposure to H2S the lungs will secrete a fluid, which
will cause further problems. Medical attention must be sought.
Acidity of H2S in solution
• H2S is acidic when it’s mixed with water.
• Eyes and nose will burn in acidic H2S environment.
• Loss of smell due to burned receptors.
H2S toxicity tables
• 20 ppm – eye, nose and throat irritation
• 20-200 ppm – loss of smell, headache and nausea
• 500-700 ppm – affects central nervous system. Loss of reasoning and
balance. Consciousness quickly is lost, and breathing stops.
• 700-1,000 ppm – Immediate loss of consciousness. Permanent brain damage.
Death will occur if not rescued immediately.
• 1,000 ppm is only 1/10th of 1%!
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Different Applications
• SCBA’s are used for safety watch and rescue operations, they are portable and
allow unrestricted mobility.
• SABA’s are used to hook up several workers at once, while providing
continuous air supply.
Advantages and Disadvantages
Here is a list of advantages and disadvantages of SCBA and SABA.
TYPE ADVANTAGES DISADVANTAGES SCBA Complete flexibility of
movement. Used for rescue operations
Allows approximately 30 minutes of air supply.
SABA Continuous air supply. Much lighter and bulkier
Limits flexibility of movement. Supply line may become wrapped around equipment and be damaged.
Factors affecting air consumption
• Size and physical condition of wearer
• Emotional state – discuss fear, hyperventilation, claustrophobia
• Physical activity of wearer
• Training in equipment usage
• Amount of air in cylinder
• Condition of equipment
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Components of SCBA
• There are many makes and models of SCBA used in the Oil and Gas industry.
They all have the same four basic components.
Air Supply
Regulator Assembly
Mask Assembly
Harness Assembly
Air Supply • The air supply is made up of three components:
An air cylinder
A cylinder valve
A cylinder pressure gauge
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Regulator Assembly • The regulator assembly consists of:
A high-pressure system
Pressure regulators
A bypass/purge valve
A pressure gauge
A low-pressure alarm
Mask Assembly • The mask assembly is made up of five parts:
A face piece
A low pressure hose/breathing tube
A nose cup
An exhalation valve
A head harness
NOTE:
The most important aspect of the face piece is the seal it forms around your face. You use the head harness to adjust the seal around your face. You must be clean-shaven where the face piece and your face meet to ensure a proper seal.
Harness Assembly • The harness assembly consists of the following:
Adjustable harness in either sling or backpack style.
Holds air cylinder in place
Key to portability of the SCBA
Allows to carry the cylinder so you can carry on your work
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Components Of SABA
• The SABA systems have a remote source of breathing air that can supply air
to several workers. It’s important that you are able to identify the major
components of the system.
• Two (2) major components of SABA are different from SCBA, and they are:
Air supply; and
Egress (Escape) Cylinder
Air Supply • Air may be supplied from a:
compressor; and
A bank of cylinders pit-tailed together
NOTE:
Verify there are no kinks, knots or damage to the air hose. There is no alarm on SABA. Should any breathing problems arise while using a supplied air system the worker must immediately disconnect the supplied air hose, open the egress cylinder and exit to a safe area.
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Cascade Storage Cylinders and Regulators
Cascade storage cylinders are pressured by a breathing air compressor. The pressure in
the storage cylinders is usually maintained at 2500 psi or 4500 psi depending on the
particular system. This high-pressure air is fed through a regulator reducing the pressure
to approximately 100 psi in order to supply air to the hoses that will be connected to the
SABA’s. The bank of cascade storage cylinders and compressor are always situated in a
safe area away from H2S.
Demonstration
Now we will have plenty of hands on practice. The instructor will demonstrate
techniques using SABA and SCBA. After you are shown the proper methods, you will
be given a chance too practice.
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Escape Cylinder
• When you enter an atmosphere that may be Immediately Dangerous to Life
and Health (IDLH), your supplied air unit must always be quipped with an
escape cylinder.
• This cylinder will last approximately 5 minutes.
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INSPECTIONS BEFORE AND AFTER USE
SCBA / SABA
• To operate breathing apparatus safely, you must be able to tell if it’s in good
repair and working properly, which is done by conducting a pre-use inspection
for both SCBA and SABA.
SCBA
SABA
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Pre-Use Inspection Checklist for SCBA
YES NO Answer all of these questions:
Are all required components available? These include:
Air cylinder
Regulator assembly
Mask assembly
Harness assembly
Cylinder at full pressure?
Low-pressure hose (breathing tube) intact? The hose clamps tight?
Regulator gauge indicate same pressure as cylinder pressure gauge?
Regulator control valves in their proper position?
Head harness intact and straps fully extended?
Mask clean and dust free?
Lens clear and free of scratches
Nose cup installed correctly?
Exhalation valve intact, clean and functioning properly?
Harness straps clean, in good repair and fully extended?
Alarm work properly?
Purge valve work?
If you answered yes to all questions, close the cylinder valve, slowly bleed pressure from the system and repack the SCBA in storage case.
Your SCBA is ready for immediate use and
***NEVER USE A DAMAGED BREATHING APPRARATUS***
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Pre-Use Inspection Checklist for SABA
YES NO Answer all of these questions:
Are all required components available? These include:
Regulator assembly
Mask assembly
Escape cylinder
Harness assembly
Escape cylinder at full pressure?
Air supply line and manifold intact?
Low-pressure hose (breathing tube) intact?
Head harness intact and the straps fully extended?
Mask clean and dust free?
Lens clear and free of scratches
Nose cup installed correctly?
Exhalation valve intact, clean and functioning properly?
Harness straps clean, in good repair and fully extended?
Purge valve work?
Your SABA is ready for immediate use if you answered yes to all questions.
***NEVER USE A DAMAGED BREATHING APPRARATUS***
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Cleaning, Inspection and Storage
It’s very important to inspect and clean your breathing apparatus after every use to ensure
it’s in good working condition for the next person.
This is what you need to perform:
• For SCBA, replace or refill air cylinder with a fully charged one.
• For SABA, replace or refill the escape cylinder if it has been used.
• Clean face piece.
• Inspect harness.
• Perform a pre-use inspection on apparatus.
• Store apparatus in appropriate area.
NOTE:
For all breathing apparatus, follow manufacturer’s specifications for maintenance, inspection and storage.
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RREESSCCUUEE The brain can only survive for approximately 4 to 6 minutes without a continuous supply
of oxygen. You should discuss as a group, in your pre-job safety meeting, a plan
designed to rescue your victim(s) to fresh air and resuscitate them within 3 minutes. A
typical response to an H2S release or alarm would be:
• Sound alarm if not already operating.
• Evacuate to upwind muster areas.
• Account for all personnel.
• Assess situation to determine best procedures for rescue and/or shut in.
• Protect personnel who will be re-entering hazardous area with appropriate
breathing apparatus.
• Perform rescue and/or shut in.
• Revive victims and send for medical assistance.
In order to expedite some of the above steps, an emergency response plan should be in
place and regular drills performed to practice the plan. The emergency response plan
should include such things as:
• Pre-job selection of rescue teams and assignment of duties.
• Map of facility to pre-plan a search pattern for missing personnel.
• Emphasis on “buddy system” and working in teams.
• At least two muster (emergency briefing) areas each equipped with SCBA’s
and rescue equipment.
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Techniques for lifting and carrying victim to safe area
Collar Drag
Used in one-on-one rescue situations. The key advantage to this technique is that the
victim’s weight does not need to be lifted.
Use the following steps:
• Victim must be on his back.
• Roll up collar on victim’s coveralls to get a firm grip.
• Support victim’s head on your forearms.
• Pull victim to safety, head first.
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Two arm drag Use this technique for two-arm drag.
• Place the victim on his back.
• Lift victim up by the back supporting the neck and head.
• Use your thigh or knee to support the victim’s back.
• Put your arms under victim’s armpits.
• Get a firm hold on victim’s wrists.
• Drag victim to safety.
Step 1
Step 2
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Two man carry This technique is referred to as a lift. Use this technique for two man carry.
• Place victim on his back.
• One rescuer places himself at the victim’s head, and supports the victim’s
head and neck.
• The other rescuer places himself at the victim’s feet, grips the victim’s wrists
and pulls him into an upright position
• The head rescuer reaches under the victim’s armpits and firmly grasps his
wrists.
• The foot rescuer faces the victim’s feet, crouches down and takes hold of the
victim’s legs.
• The rescuers work together to lift the victim evenly.
Step 2
Step 1
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Rescue Breathing and Cardio Pulmonary Resuscitation (CPR)
It is recommended that First Aid and CPR techniques be taught to International Red
Cross/Red Crescent standards.
These guidelines are general information. It’s important that you continue to learn the
skills required in First Aid/CPR.
STEP 1
STEP 2
Determine Unresponsiveness
Check Breathing
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STEP 3
STEP 4
Give 2 slow breaths
Check Pulse
Recovery Position
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Medical Attention
Removing a victim from a contaminated H2S area may not be enough to save his life. If
a victim is not breathing, administer artificial respiration. During this lesson, the
instructor will demonstrate the proper procedure for rescue breathing. Please refer to the
notes above as a guideline.
A victim of H2S inhalation is in danger of developing medical complications for some
time after he has been rescued. Once the immediate H2S emergency has been brought
under control, victims should be transported to a health care facility at which they can
receive professional medical attention and remain under observation until released by the
appropriate medical authorities.
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Electronic H2S Monitors
Electronic monitors use sophisticated electronics to measure the concentration of H2S and
other hazardous gases.
Electronic monitors contain a sensor, which may be powered by batteries or AC power.
Components of personal, portable and fixed monitors:
• If it’s a personal, portable or fixed monitor, the basic components of the unit
include:
Power source
Sensor(s)
Visual display (flashing light or read-out)
Audible alarm
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Personal monitors
• Designed to be worn by the worker, may clip onto a belt, fit in an outside
pocket or be worn on a harness.
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Portable monitors
• Designed to be placed between the worker and the source of H2S, or in a
confined space.
NOTE:
Always follow the recommended manufacturer’s instructions when operating a personal or portable monitor.
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Fixed monitors
• Most sophisticated type of electronic monitor. Permanently installed units
and usually found in gas plants and oil batteries.
• The system consist of:
Central control unit
Remote display(s)
Remote sensor(s)
Alarm(s)
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Tube types – Bellows and Piston
Piston-Type Unit
It’s a pump operated by the action of a piston to create a vacuum.
• A pump consist of the following:
cylinder
piston with handle
inlet
vacuum indicator
valves and seals
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Bellows-Type Unit
A bellows pump is used to create the vacuum necessary to take a sample.
• A bellows-type unit consists of:
A spring-loaded bellows
Inlet
Vacuum indicator
Stroke counter
A valve and seals
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Detector Tubes
There are various types of indicator tubes designed to detect a wide variety of gases.
• All tube manufacturers make tubes designed for different types and
concentrations of gas.
• The concentration readings on the tube are in either ppm or percentages.
• The accuracy of detector tubes may vary by up to (+-25%) of the true gas
concentration depending upon their make and type.
• Some elements that affect the accuracy of a detector tube reading include:
condition of the pump (air tightness)
age of the tube (check expiry date on box)
temperature
operating procedures
storage conditions
interferences from other airborne contaminants
• Always store detector tubes in a cool dark place.
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Instructor’s Demonstration
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Multigas Monitor - Lower Explosive Limit (LEL)
The Watchman Multigas Monitor is a durable, hand-held instrument used to detect and
monitor combustible gases, oxygen and toxic gases in workplace atmospheres, especially
in confined spaces such as manholes, storage tanks, tank cars, vaults, mines and sewers.
If the combustible gas level reaches 100% of the Lower Explosive Limit (LEL), the
alarm locks and cannot be reset until the user moves to fresh air, turns the unit off and
back on again.
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SO2 Monitors
For continuous area monitoring and alarm of toxic gases in the workplace environment.
For chlorine/chlorine dioxide, fluorine/hydrogen fluoride, sulphur dioxide (SO2),
hydrogen sulphide and hydrogen chloride.
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