Unrestricted
What you will Learn
What is a Confined Space
Hazards of Confined Spaces
Basic Entry Requirements
General Requirements
All employees required to enter confined or
enclosed spaces must be instructed in:
• nature of the hazards
• necessary precautions to be taken
• use of protective and emergency
equipment
What is a Confined Space?
Is large enough and so configured that an
employee can bodily enter and perform
assigned work
Has limited or restricted means for entry or
exit (for example, tanks, vessels, silos,
storage bins, hoppers, vaults, and pits are
spaces that may have limited means of
entry.)
Is not designed for continuous employee
occupancy.
What is a Permit Required
Confined Space?
A Permit-required confined space is
confined space that has one or more of
the following characteristics:
Permit Required Spaces
Contains or has a potential to contain a
hazardous atmosphere
Contains a material that has the potential
for engulfing an entrant
Permit Required Spaces
Has an internal configuration such that an
entrant could be trapped or asphyxiated by
inwardly converging walls or by a floor
which slopes downward and tapers to a
smaller cross-section
Contains any other recognized serious
safety or health hazard
Typical Confined Spaces
Boilers & Furnaces
Pipelines
Pits
Process Vessel
Silo & Storage Tanks
Sewer & Manholes
Trenches & Excavations
Hazards of Confined Spaces
Atmospheric
Physical Configuration
Mechanical
Electrical
Thermal
Noise
Vibration
Engulfment or Entrapment
Controlling Confined Space
Hazards
Each Confined Space has different hazards.
Hazards can also change with time and
usage.
– Post signs to warn of the dangers.
– Use barriers to prevent uncontrolled
access
– Develop and use a written space entry
program.
Controlling Confined Space
Hazards
– Conduct air monitoring and tests to
identify and evaluate hazards.
– Define acceptable entry conditions.
– Monitor entry conditions
– Eliminate or control the space's
atmospheric hazards before entry
– Lockout all internal hazards prior to entry
Entry Point Hazards
Small Openings make entry and
rescue difficult
Sharp edges can tear protective
clothing or air lines
Temporary ladders and vent gear can
make even large openings difficult to
transit
Vertical entry points are fall hazards
Ventilation Needed
Deadly gases can be trapped inside
Rotting Organic materials create
hazardous gases
Pipe leaks, welding, system material
can create hazardous atmospheres.
Rust consumes the oxygen you need.
Atmospheric Hazards
Oxygen Deficient Atmospheres
Oxygen Enriched Atmospheres
Flammable Atmospheres
Toxic Atmospheres
Corrosive Atmospheres
Asphyxiating Atmospheres
Oxygen Deficient
19.5 % is the minimum acceptable
oxygen level for work with out an air
supplied respirator.
12-14% - Poor judgment.
10-12% - Lips blue Mental Confusion
8-10% - Fainting & Nausea
6-8% - Causes Death
Asphyxiating Atmospheres
Reduction of oxygen in a confined space may
be the result of either consumption or
displacement. Consumption of oxygen
takes place during
– Combustion of flammable substances
– Bacterial action, as in the fermentation process
– Chemical reactions as in the formation of rust
Oxygen Enriched
Oxygen level above 21%.
Causes flammable and combustible materials
to burn violently when ignited. Such as:
Hair, clothing, oil soaked materials
Never use pure oxygen to ventilate.
Never store or place compressed gas tanks in
a confined space.
Flammable Atmospheres
Required Factors:
– Oxygen
– Flammable Gas, Vapor or Dust
– Ignition Source
• Welding
• Electric Tools
• Sparks
• Smoking
Flammable Atmospheres
Caused by…
– enriched oxygen atmospheres
– vaporization of flammable liquids
– byproducts of work
– chemical reactions
– concentrations of combustible dusts
– fumes from chemicals on inner surfaces
Toxic Atmospheres
Material in space
• Absorbed materials can “gas off”.
• Decomposition of materials
Work being performed
• Welding, cutting, brazing, soldering.
• Painting, scraping, sanding, degreasing.
• Sealing, bonding, melting.
• Cleaning, descaling
Corrosive Atmospheres
Corrosive atmospheres can be not only a
respiratory problems but also cause skin
exposure reactions and damage to your
nervous system though skin absorption or
breathing.
Examples of Corrosives
• Bleach
• Ammonia
• Acids
Physical Configuration Hazards
The use and shape of a space can create
hazardous conditions
• Use of Ladders & Scaffolding
• Wet or slippery surfaces
• Uneven bottoms
• Bends in tunnels
• Narrow areas that can entrap workers
• Poor lighting
Use retrieval & fall protection when possible
Mechanical Hazards
Some confined spaces have unguarded
mechanical equipment such as:
• Paddles
• Blades
• Shafts
• Chain or belt drives
All equipment must be Locked and Tagged
before entry
Electrical Hazards
Electric Shock is a possible hazard in
Confined Spaces
Hazard Sources include:
• Broken lighting
• Electrical sensing devices
• Limit switches
• Level indicating devices
• Hazards from equipment taken
inside
Temperature Hazards
High and Low Temperatures are Hazards
Burns
Frosbite
Heat Stress
Wearing Protective clothing can increase
the heat stress on a worker
Worker Comfort
Factors affecting worker comfort:
• Air temperature
• Air velocity though the space
• Humidity
• Radiant heat
• Protective Clothing
• Activities
Engulfment Hazards
Engulfment is the entrapment of a person by
the contents of a space
•Liquids
•Small granular product such as grain
•Crusting or Bridging of material
•Flooding
•Water Flow
Engulfment Hazards
Completely empty the contents before
entry
Use retrieval and fall arrest equipment
to prevent sinking into contents of a
space.
Noise Hazards
Noise creates a hazard by
• Causing hearing loss
• Preventing communication
• Lowering worker's effectiveness
Eliminate noise sources prior to entry
Use proper hearing protection
Surface Hazards
Slippery, Wet or Damp Surfaces
• Slips & Falls
• Chemical Exposure
• Possible increased chance of
electric shock
• Uneven surfaces
Vibration Hazards
Vibration of the body can cause damage to
the body
Using Vibrating tools can cause damage to
fingers & hand
Eliminate equipment vibrations prior to
entry
Use Vibration dampening tools & gloves
Basic Confined Space Entry
Procedure
All entrants, supervisors and entry
attendants must be fully qualified
1. Conduct Pre-Entry Briefing
2. Assemble and check equipment
3. Establish Acceptable Entry Conditions
4. Conduct initial air sampling
5. Execute & Complete Entry Permit
6. Station Entry Attendant
Entry (continued)
7. Establish Monitoring of Atmosphere
8. Establish Communication
9. Execute Hot Work Permit if applicable
10.Post Confined Space Entry Permit
11. Enter Space
12. Post–entry debrief if problems were
encountered
Testing The Atmosphere
Verify presence of safe work atmosphere.
Calibrate Air Monitoring Equipment
before use
Test all areas of a confined space
– Top, Middle, Bottom
– Check for Explosive & Toxic Gases
– Check Oxygen level
Record all readings
Ventilation
Consider best of exhaust or supply or both
Provide workzone exhaust if welding
Plan ventilation supply and exhaust paths
Ensure no “re-circulation” of air supply
Use continuous ventilation
Retest the confined space before and during
entry
LOCKOUT!
Lock & tagging ALL electrical sources.
Blank & bleeding fluid lines
Disconnect mechanical drives &shafts.
Secure mechanical parts
Lock & Tag all valves
Rescue Team
A qualified rescue team and rescue equipment
must be available for entry into all Permit
Required Confined Spaces
Qualified Entry Attendant must be in constant
communication with workers in the space
Entry Attendant must have source of
communication with the Rescue Team
Summary
All persons involved in Permit Required
Confined Space Entry must be qualified:
Supervisor
Attendants
Entrants
Rescue Team
Confined Spaces are Dangerous Places –
Know how to control or eliminate
hazards
