Prepared by: Riad Lakhel
Definition of a Confined Space
any space which/where:
• is big enough to work in.
• has limited entry and exit.
• is not designed for continuous worker occupation.
• where there could be a lack of oxygen
• where flammable or toxic vapours may be present.
Do not get into the confined space
unless all other options have been
ruled out.
Examples of Confined Spaces:
• Tanks • Vaults
• Manholes • Pipes
• Boilers • Trenches (1.25m & more)
• Furnaces • Tunnels
• Sewers • Pits
• Silos • Process Exchangers
3
Examples of Confined Spaces
PIPES; TANKS;
VESSELS;
Hopper
always follow the company’s permit procedures,
even if you are going in for just a second.
ANY entry and for ANY duration, so a
“quick look” still requires all of the
appropriate measures for confined
space work
5
Hazards of Confined Spaces
• Oxygen Deficient Atmospheres
• Oxygen Enriched Atmospheres
• Flammable Atmospheres
• Toxic Atmospheres
• Mechanical and Electrical Hazards
• Temperature Extremes
• Noise, Slick/Wet Surfaces, Falling Objects, rats and snakes.
6
How Air is Composed
78%
Nitrogen
21%
Oxygen
1%
Other
Prepared by: Riad Lakhel
CONFINED SPACE HAZARDS
Oxygen Level
23% Too much, oxygen enriched
Safe Zone - Minimum for safe
entry
19.5%
Impaired judgement &
16% breathing
Faulty judgement, rapid
14% fatigue
Difficult breathing, death in
6%
minutes
8
CONFINED SPACE HAZARDS
SIGNS OF A PROBLEM
Lack of Oxygen:
• Shortness of breath
• Disorientation
•Weakness
• Nausea and Vomiting
Oxygen Enriched Atmospheres
• Oxygen level above 23%.
• Causes flammable and combustible materials to
burn violently when ignited.
• Hair, clothing, materials, etc. can easily catch fire.
• Oil soaked clothing and materials.
• Never use pure oxygen to ventilate.
• Never store or place compressed GAS CYLINDERS
in a confined space.
10
Flammable Atmospheres
• Oxygen content in the air.
• Presence of a flammable gas, or vapor
• Presence of dust
• Typical Ignition Sources:
– Sparking or electric tool.
– Welding / cutting operations.
– Smoking
00% of the Lowest Explosive Level
11
Toxic Atmospheres
12
Prepared by: Riad Lakhel
Carbon Monoxide
• Odorless, Colorless Gas.
PPM Effect Time
35 Permissible Exposure Level 8 Hours
200 Slight headache, discomfort 3 Hours
600 Headache, discomfort 1 Hour
1000-2000 Confusion, nausea, headache 2 Hours
1000-2000 Tendency to stagger 1 1/2 Hours
1000-2000 Slight heart palpitation 30 Min.
2000-2500 Unconsciousness 30 Min.
13
S
H H
What is H2S?
H2S is naturally occurring chemical produced by
bacteria as it decomposes organic material.
It may develop in low oxygen environments, such
as, sewers, swamps and polluted water.
Hydrogen Sulfide Gas is a toxic (poisonous) gas
that can kill you the first time you breathe it!
Target Organs
Nose Lungs
Respiratory
control center
Liver Eyes 14
Physical characteristics
•Possibly no warning at high concentrations.
•Color – Clear/Transparent
•Odor – Sweetish taste, unpleasant odor;
described as rotten eggs.
•Density – heavier than air
PPM Effect Time
10 ppm Permissible Exposure Level 8 Hours
50–100 Mild Irritation - eyes, throat 1 Hour
200–300 Significant Irritation 1 Hour
500-700 Unconsciousness, Death 1/2 - 1 Hour
>1000 Unconsciousness, Death Minutes
15
CONTROL TECHNIQUES
Ventilation (OXYGEN DEFICIENCY)
Use mechanical ventilation
– Fans
– Larger spaces require more
ventilation
Make sure air supply is not
contaminated
– Ventilation air supply must be
from fresh air uncontaminated
with flammables, toxins, etc.
16
CONTROL TECHNIQUES
Inerting (FLAMMABLE GASES)
The displacement of the atmosphere in a permit space by a
noncombustible gas (such as nitrogen) to such an extent that
the resulting atmosphere is noncombustible.
NOTE: This procedure produces an IDLH oxygen-deficient
atmosphere.
Flushing (Pipework Purging by Water Flushing)
Blowing through steam to purge debris, in a pipe for instance.
Some confined spaces can contain mixing or crushing mechanisms or other
hazards that can be turned on and injure a worker
Lockout/tagout is used on all hazardous items
Test the Atmosphere
In this order:
Check for Oxygen Content:
At least 19.5% and less than 23%
Check for Combustibles:
10% of the LLF max.
Check for Toxic Gases:
Most commonly:
- carbon monoxide (PEL <35 ppm)
- Hydrogen sulfide (PEL <10 ppm)
or any other hazardous materials as
determined by the use of the space.
19
Test the Atmosphere
Don´t rely on your sense of smell; use a calibrated gas detector
20
Reading a gas detector
Check that the battery
atmospheric conditions may change is fully charged
while you are in the confined space
periodically monitor the atmosphere within the confined space 21
Testing The Atmosphere
• Verify presence of safe work atmosphere.
• Test all areas of a confined space.
– Top, Middle, Bottom
• Methane is lighter than air.
• Carbon Monoxide is the same as air.
• Hydrogen Sulfide is heavier than air.
• Oxygen Deficiency.
22
Temperature Extremes
Extreme Cold Extreme Heat
Prepared by: Riad Lakhel
Other Hazards
• Noise
• Amplified due to acoustics within the space.
• Damaged hearing, affect communication.
• Slick / Wet Surfaces
• Slips and falls.
• Increased chance of electric shock.
• Falling Objects
• Topside openings expose workers inside confined space to
falling objects.
• Presence of rodents, vipers, insects, scorpions.
24
Entry Teams
• Confined Space Entry Persons
– Entry Supervisor
– Entrant
– Attendant
– Rescue Team (if necessary)
Conduct a Toolbox Talk
• Entire crew must attend
– Entry supervisor, entrants, Attendants
• Review hazards of entry and work
• Review PPE
• Review procedure for contacting rescue
• Complete permit
26
CONFINED SPACE ENTRY PERMIT
•Area identified as Confined Space
• Scope of the work
• How long the work will take
•Names of all team members and
their duties
Entry Crew (1/3)
ENTRY SUPERVISOR DUTIES (The worker responsible for
RESPONSIBILITIES
OVERSEEING confined space entry operations, permit signing and safety
conformance) Continued
Know the hazards associated with the space
Ensure all tests, procedures and equipment are used
Verify that rescue services are available
Remove unauthorized individuals attempting spaces
Entry Crew (2/3)
ENTRANT DUTIES (A worker authorized to enter a confined space)
Know the hazards associated with the space
RESPONSIBILITIES
Follow the instructions on the permit
Use required equipment properly
Continually communicate with the attendant
Alert the attendant when necessary
Exit the space quickly when so required
Leave any food, beverages, and cigarettes
outside the space.
All entrants shall sign the sign in log when entering the
space and sign out when exiting.
LIFELINES
• When the entrant must enter a confined space
through a manhole or other small opening,
means shall be provided for quick removal in
case of emergency.
Entry Crew (3/3)
ATTENDANT DUTIES (An observer stationed outside of a confined space)
Know the hazards associated with the space
RESPONSIBILITIES
Maintain accountability of entrants through a log sheet
Continued
Remain on duty until properly relieved
Communicate with the entrant as appropriate
Monitor activities inside and outside the space
Summon rescue assistance when needed
Perform non-entry rescue
HSE personnel should Check that:
PPE is properly worn
tools are inspected
involved personnel is trained
means of communication are in place
warning signs are posted & barriers are erected
No one to enter a confined space to rescue an unconscious
person unless trained and wearing a breathing apparatus
Lone workers will not be allowed to enter confined spaces
If it is unsafe stop work
33
Equipment which may be needed
Multi-gas monitors
Body harnesses
Extraction cables and lanyards
Escape ladders
Rescue tripod and winch system
Ventilation equipment
Hand tools
First aid kits
Intrinsically safe lighting
Communications equipment
Personal protective equipment
Supplied Air / Air purifying respirators
Lanyard
LIGHTING AND ELECTRICITY
Use 24 volt during situations where hydrocarbon, flammable,
and explosive atmospheres exists.
When using portable electrical tools, be sure they are:
Double-insulated
Suspend all electric power cables so they do not create a
trip hazard.
Rescue Service Member
Emergency rescue must be readily available to the confined space
entry attendant for emergency extrication of entrants
Rescue requires rescue training and practice drills. NEVER attempt
a rescue you are not properly trained for.
Rescuers Account for Over 60% of Confined
Space Fatalities
36
37
When the Job is Done:
• Remove all personnel, tools, and debris from the space.
Sign off the log.
• Close the space.
Cancel the permit.
If any thing has gone wrong, report it immediately.
38
SUMMARY
Entry only by:
1.Trained staff
2.Permit to work & watchman
3.Gas Testing
5.Ventilation system
4.Safe access and lighting
6.Rescue plan
39
40
