Confined space entry

1By Tony Bertram, safety team member
Confined Space EntryConfined Space Entry
Environmental Safety & Health - Safety Center

Why are we here?
OSHA and this company require that all employees who
must enter into confined spaces receive training as to the
hazards, procedures and equipment required to do so
safely.
O2 and You.

Definitions:
The entrant is the person who enters a confined space.
The attendant is the person who stays with the entrant
outside the confined space, and is responsible for assisting
the entrant in exiting the confined space, and calling for
emergency assistance when required.
The safety representative is the qualified person who
evaluates the hazards, prescribes required equipment
and precautions and issues the Confined Space Entry Permit.

Goals and Objectives:
At the end of this session you will:
o be familiar with the hazards and requirements
of “safe” confined space entry.
o pass a 10 question quiz with a score of 100%.

Confined Space Entry - HazardsConfined Space Entry - Hazards
Both animal and plant life
require oxygen to live. One of the
primary hazards of entering
confined spaces is oxygen
deficiency.
When oxygen is present in
concentrations less than 19.5%
the atmosphere is said to be
oxygen deficient.
O2
O2

Oxygen can also be present
in concentrations that are
too high.
Oxygen in concentrations
greater than 23% is too
oxygen rich and can cause
combustible materials to
ignite very quickly.

Oxygen deficiency can be caused by several
processes:
Consumption: oxygen is used up by the person who is in the
confined space and turned into carbon
dioxide.
Displacement: denser materials push the oxygen out of
the occupied space.
Reaction: oxygen is reacted with other materials
to make other compounds.

The human body requires
oxygen to carry out cellular
metabolism. Oxygen is
brought in through the lungs
and transported to cells of
body organs by the red
blood cells. When blood is
rich in oxygen it turns red.
O2CO2
After oxygen is delivered
to body organs and used
by organ cells, it reacts
with carbon to make
carbon dioxide. Red
blood cells carrying
carbon dioxide turn
blue. Carbon dioxide is
carried back to the lungs
by the red blood cells
and exhaled into the
surrounding atmosphere.

CO2
O2
Given a fixed amount of oxygen
as you would have in a confined
space, respiration of oxygen
causes carbon dioxide to
increase. When oxygen
decreases to less than 19.5%.
the atmosphere is said to be oxygen
deficient, putting occupants of
the confined space at risk of
losing consciousness and death.

Processes which operate by the
principle of combustion use up
oxygen much faster than the
human respiration.
Products of combustion vary
with the fuel that is present and
the temperature of the combustion
reaction. Welding, burning natural
gas, propane, gasoline, and diesel
engines are examples of combustion
processes.
CO2
H20
NOx
CO
O2
fuel

Manholes often remain
covered for long periods
of time. Naturally
occurring toxins, such
as hydrogen sulfide
can accumulate inside of
manholes.
H2S
Manholes may also
accumulate highly
flammable gasses
such as methane
and ethane. Unlike
the gas we receive at
home, we cannot detect
some of these gases with
our sense of smell.
CH4

Toxic and flammable
materials are sometimes
illegally put into sanitary
and storm sewers.
Leaking tanks or spills
may migrate under
ground causing seepage
into manholes.
??
??
??
??
Material can leach
through soil from
many miles
away.
??

Sudden releases of
fluid solids, such as
granulated salt, sugar,
or sand, liquids, and
dense gases can cause
engulfment of persons
inside underground
tanks, or pits.
When torrential forces
are suddenly released,
people may be struck
by moving objects , or
be pushed helplessly
downstream.

Trenches, ravines and other
excavations may also
be considered confined
spaces, if there is a
potential for accumulation
of toxic gases, engulfment
and/or the depletion of
oxygen.
?

Many confined space
entries involve a
complex set of exposures
to mechanical, electrical,
pressure and chemical
hazards.

The entry of a confined space begins with a
Confined Space Entry Permit.
Confined Space Entry Permit
Location and Description of Confined Space:
Reason for Entry:
Permit Issued to (Name of Company/Organization):
Location and Description of Confined Space:
Reason for Entry:
Permit Issued to (Name of Company/Organization):
The permit system requires
that a qualified safety
representative visit the
work location and evaluate
the conditions under which
entry will be made.

Each process hazard to which
the entrant may be exposed,
adjacent operations or processes,
and scheduled activity
are reviewed. For each hazard
identified, countermeasures
are detailed on the Confined
Space Entry Permit.

The safety representative
tests the space for
hazardous concentrations
of known harmful
substances, such as
hydrogen sulfide,
carbon monoxide, and
flammable liquid or gas.
The concentration
of oxygen is measured
at the same time.

If concentrations of
materials are found to
be at harmful levels,
the confined space
must be ventilated to
remove them before
entry.
??
??
??
??
Fresh Air
Fresh outside
air is blown into
the space to dilute
and remove
contaminants, and
supply oxygen.
Fresh outside
air is blown into
the space to dilute
and remove
contaminants, and
supply oxygen.
O2
O2
O2
O2

Should the concentration
of contaminants remain
at harmful levels,
respirators may have to
be worn to assure a safe
air supply.
Should the concentration
of contaminants remain
at harmful levels,
respirators may have to
be worn to assure a safe
air supply.
??
??
??
Fresh Air
O2
O2
O2
O2
??

Means of emergency rescue
must be readily available
to the confined space
entry attendant for
emergency
extrication of
entrants.

ConfinedConfined
Space EntrySpace Entry
A means must be provided
for both safe normal entry
or exit , and emergency
extrication. Tripods with hoist,
lifeline, and full body harness
are often used for emergency
extrication. Ladders may be
used for ordinary entry and
exit.

ConfinedConfined
Barriers to prevent passers-by
and the curious from falling
into the opening must be put
in place.
Holes and openings must be
closed or guarded when not
attended.

ConfinedConfined
Place warning signs where
pedestrians can see them.
Signs must state the hazard
and the required action.
CAUTION
Opening in Ground
Keep Out !

Requirements
Eye protection yes no
Respiratory protection yes no
Continuous Ventilation yes no
Body Protection yes no
Hand Protection yes no
Foot Protection yes no
Weather Protection yes no
Requirements
Required countermeasures include
personal protective equipment
for hazards expected to be found
within the confined space.
Eye and head injuries are always
a potential, therefore safety glasses
and hard hats are required wear
for entrants.
Other conditions may require the
use of respirators, safety shoes,
protective gloves, and other
personal protective equipment.

o
Danger
Do not use!
o
Danger
Do not use!
Requirements
Ground Fault Interruption yes no
Lockout of Hazardous
Energy Sources yes no
Requirements
Ground Fault Interruption yes no
Energy Sources yes no
Required countermeasures also
include prevention of electrical
shock hazards due to loss of
earth ground for portable tools.
GFCI’s are required for portable
electric tooling.
There may also be a need to
lockout and tag equipment both
in the confined space and on
adjacent equipment and processes.

H2S
HCN
Entrants must leave the
confined space when the
monitor alarm is activated.
It is the attendant’s
responsibility to see that
the entrant leaves the
space during an alarm.
Entrants must leave the
confined space when the
monitor alarm is activated.
It is the attendant’s
responsibility to see that
the entrant leaves the
space during an alarm.CH4
CO
CO2
O2
Entrants must constantly monitor
the confined space for toxic gases,
oxygen, and combustible gases.
Entrants will be issued a personal
monitor to wear
for this
purpose.

Should conditions develop
which require extrication,
and the entrant cannot
get out of the confined
space on their own,
the attendant must
call for emergency
assistance at once!
Should conditions develop
which require extrication,
and the entrant cannot
get out of the confined
space on their own,
the attendant must
call for emergency
assistance at once!

The attendant should
attempt to remove the
entrant from the confined
space using tripods, hoist, and
lifelines. Attendants are NOT
TO ENTER CONFINED
SPACES. Lethal hazards may
be present within the confined
space. Only properly
equipped
and trained emergency rescue
personnel may enter confined
spaces to make rescues.
The attendant should
attempt to remove the
entrant from the confined
space using tripods, hoist, and
lifelines. Attendants are NOT
TO ENTER CONFINED
SPACES. Lethal hazards may
be present within the confined
space. Only properly
equipped
and trained emergency rescue
personnel may enter confined
spaces to make rescues.

Confined Space Entry - SummaryConfined Space Entry - Summary
Confined space entry hazards can include:
- the presence of toxic substances
- insufficient oxygen, or too much oxygen
- engulfment
- presence of combustible gases and liquids
- process or equipment related hazards.
- conditions changing from nonhazardous
to hazardous.

Confined Space Entry - SummaryConfined Space Entry - Summary
Location and description of confined space:
Reason for entry:
Permit issued to:
Supervisor’s Name:
Attendant’s name:
Permit issuer’s name:
% oxygen: % lower explosive limit: ppm CO: H2S:
Requirements
Emergency Rescuer yes no
Continuous Gas Monitor yes no
Barrier for ground openings yes no
Warning Signs yes no
Safety Harness with
life line yes no
Tripod / Hoist / Pulley yes no
Access (ladders/other)yes no
Ground Fault Circuit
Interrupters yes no
Energy yes no
Location and description of confined space:
Reason for entry:
Permit issued to:
Supervisor’s Name:
Attendant’s name:
Permit issuer’s name:
% oxygen: % lower explosive limit: ppm CO: H2S:
Requirements
Emergency Rescuer yes no
Continuous Gas Monitor yes no
Barrier for ground openings yes no
Warning Signs yes no
Safety Harness with
life line yes no
Tripod / Hoist / Pulley yes no
Access (ladders/other)yes no
Ground Fault Circuit
Interrupters yes no
Energy yes no
Required countermeasures are
determined by a qualified safety
professional.
Once the required countermeasures
are in place, a permit is issued by
the safety representative and the
confined space may be safely
entered.
Should an emergency arise during
the entry, the attendant notifies
an emergency response team and
attempts to extricate the entrant.

Confined Space Entry -SummaryConfined Space Entry -Summary
Confined Space
Safe Work Permit Required
CAUTION
Confined spaces are required to be labeled. Some spaces
may have been overlooked. Contact your safety representative
when in doubt. It is up to you to obey signs and to follow
permit procedures before entry.

Where to Get Help?Where to Get Help?
The supervisor of a confined space entry should be contacted
for any equipment necessary to complete the task at hand.
Safety Representatives are responsible for answering questions
about the confined space entry permit, countermeasures,
sampling methods, and instrumentation.

References and Sources forReferences and Sources for
More InformationMore Information
OSHA 29CFR 1910.146 Permit - Required Confined Spaces

Think before entering space!

Confined Space Entry
• Construction Industry Standard
1926.21(b)(6)
• General Industry Standard
1910.146
• Best Practices for all Industries

Construction Industry Standard
All employees required to enter into
confined or enclosed spaces shall be
instructed as to the nature of the hazards
involved, the necessary precautions to be
taken, and in the use of protective and
emergency equipment required. The
employer shall comply with any specific
regulations that apply to work in dangerous
or potentially dangerous areas.

Typical Confined Spaces
• Boiler, Degreaser, Furnace
• Pipeline, Pit, Pumping Station
• Reaction or Process Vessel, Mills
• Septic Tank, Sewage Digester
• Silo, Storage Tank, Barges
• Sewer, Utility Vault, Manhole
• Trenches, Shafts, Caissons

How to Identify Confined Spaces
• Limited Openings for Entry and Exit
• Unfavorable Natural Ventilation
• Not Designed for Continuous Worker
Occupancy

Categorizing Work Space
* Space large enough to enter &;
* Limited or Restricted entry or exit &;
* Not designed for continuous worker
occupancy.
NO
Not a confined Space
YES
Confined Space
Hazardous Atmosphere
Engulfment Hazard
Configuration Hazard
Any other recognized
serious hazard
Permit-
Required
Confined
Space
Non
Permit
Required
Space
YES NO
Or
Or
Or

Limited Openings for Entry/Exit
• Openings as small as 18 inches in diameter.
• Difficult to enter with SCBA or other life-
saving equipment.
• Difficult to remove downed worker in
folded up or bent over position.
• Exit from large openings may be difficult
due to presence of ladders, hoists, etc.

Unfavorable Natural Ventilation
• Lack of air movement in and out of the
space can create an atmosphere much
different than the outside atmosphere.
• Deadly gases can be trapped inside.
• Organic materials can decompose.
• May not be enough oxygen due to presence
of other gases or chemical reactions such as
rusting.

Not Designed for Continuous
Worker Occupancy
• Most confined spaces are not designed to
enter and work in on a regular basis.
• Designed to store a product.
• Enclose materials or processes.
• Transport products or substances.
• Occasional worker entry for inspection,
repair, cleanup, maintenance, etc.

Dangerous Combinations
• Presence of all three confined space
characteristics can complicate the situation.
• Working in and around the space.
• Rescue operations during emergencies.
• Worsened conditions due to work activities:
– Welding and cutting, use of bonding agents
– Cleaning with solvents, use of other chemicals
– Use of gas-powered equipment

Hazards of Confined Spaces
• Oxygen Deficient Atmospheres
• Oxygen Enriched Atmospheres
• Flammable Atmospheres
• Toxic Atmospheres
• Temperature Extremes
• Engulfment Hazards
• Noise, Slick/Wet Surfaces, Falling Objects

Oxygen Deficient Atmospheres
19.5 % Minimum acceptable oxygen level.
15 - 19% Decreased ability to work strenuously.
Impair coordination. Early symptoms.
12-14% Respiration increases. Poor judgment.
10-12% Respiration increases. Lips blue.
8-10% Mental failure. Fainting. Nausea
Unconsciousness. Vomiting.
6-8% 8 minutes - fatal, 6 minutes - 50% fatal
4-5 minutes - possible recovery.
4-6% Coma in 40 seconds. Death

Oxygen Enriched Atmospheres
• Oxygen level above 21%.
• Causes flammable and combustible
materials to burn violently when ignited.
• Hair, clothing, materials, etc.
• Oil soaked clothing and materials.
• Never use pure oxygen to ventilate.
• Never store or place compressed tanks in a
confined space.

Flammable Atmospheres
• 2 Critical Factors:
– Oxygen content in the air.
– Presence of a flammable gas, or vapor
– Presence of dust (visibility of 5’ or less)
• Proper air/gas mixture can lead to explosion
• Typical Ignition Sources:
– Sparking or electric tool.
– Welding / cutting operations.
– Smoking

Toxic Atmospheres
• Product stored in a confined space:
• Gases released when cleaning.
• Materials absorbed into walls of confined space.
• Decomposition of materials in the confined space.
• Work performed in a confined space:
• Welding, cutting, brazing, soldering.
• Painting, scraping, sanding, degreasing.
• Sealing, bonding, melting.
• Areas adjacent to a confined space.

Hydrogen Sulfide
• Decomposition of materials. Human waste.
• Rotten egg odor at low concentrations.
• Possibly no warning at high concentrations.
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

Carbon MonoxideCarbon Monoxide
• Odorless, Colorless Gas.Odorless, Colorless Gas.
• Combustion By-Product.Combustion By-Product.
• Quickly collapse at high concentrations.Quickly collapse at high concentrations.
PPMPPM EffectEffect TimeTime
5050 Permissible Exposure LevelPermissible Exposure Level 8 Hours8 Hours
200200 Slight headache, discomfortSlight headache, discomfort 3 Hours3 Hours
600600 Headache, discomfortHeadache, discomfort 1 Hour1 Hour
1000-20001000-2000 Confusion, nausea, headacheConfusion, nausea, headache 2 Hours2 Hours
1000-20001000-2000 Tendency to staggerTendency to stagger 1 1/2 Hours1 1/2 Hours
1000-20001000-2000 Slight heart palpitationSlight heart palpitation 30 Min.30 Min.
2000-25002000-2500 UnconsciousnessUnconsciousness 30 Min.30 Min.

Temperature Extremes
• Extremely hot or cold temperatures.
• Steam cleaning of confined spaces.
• Humidity factors.
• Extremely cold liquids.
• Work processes inside the confined space
can increase temperature extremes.
• Personal protective equipment.

Engulfment Hazards
• Loose, granular materials stored in bins and
hoppers - grain, sand, coal, etc.
• Crusting and bridging below a worker.
• Flooding of confined space.
• Water or sewage flow.

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.

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.

Ventilation
• First option to correct problems.
• Must be aware of hazards you are trying to
correct in the confined space.
• Air intake in a safe location to draw fresh
air only.
• Continuous ventilation whenever possible.
• Retest the confined space before entry.

Isolation
• Locking and tagging out electrical sources.
• Blanking and bleeding pneumatic and
hydraulic lines.
• Disconnecting mechanical drives and
shafts.
• Securing mechanical parts.
• Blanking sewer and water flow.
• Locking and tagging out shutoff valves.

Respirators
• Air-Purifying Respirators
– Filter dangerous substances from the air.
– Must know the type and amount of hazardous
substance present in the confined space.
– NEVER use with oxygen deficiency!
• Air-Supplying Respirators
– Deliver a safe supply of breathing air from a
tank or an uncontaminated area nearby.
– Must be adequately monitored.

Standby / Rescue
• Worker assigned to remain outside the
confined space and be in constant contact
with the workers inside.
• Know emergency rescue procedures.
• 50% of workers who die in confined spaces
are would-be rescuers.
• Trained in use of emergency rescue
equipment and PPE.

Permit Entry Systems
• Written permit signed by entry supervisor.
• Verifies pre-entry precautions have been
taken and the space is safe to enter.
• Posted at entry to confined space.
• Specifies apparent hazards and corrective
actions taken prior to entry.
• Requires termination of permit when task is
completed or when new conditions exist.

Entry Permit Requirements
• Date, location, and name of confined space.
• Purpose of entry and known hazards.
• Duration of entry permit time.
• Authorized entrants, attendants,
supervisors.
• Air testing results - signature of tester.
• Protective measures to be taken.
• Ventilation, Isolation, Flushing
• Lockout / Tagout, Purging

Entry Permit Requirements
• Name and phone numbers of rescue and
emergency services.
• Communication procedures.
• Special equipment and procedures.
– Personal protective equipment.
– Alarm procedures.
– Rescue equipment.
– Respirators.

Training and Education
• All workers who must enter confined spaces
• All attendants and rescue team members.
• Prior to initial work assignment.
• Retraining:
• Job duties change.
• Change in permit-space program.
• New hazards are present.
• Job performance indicates deficiencies.

Confined space entry

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