How does it work Confined Space safely ?

What is a Confined Space?

Is large enough and so configured that an employee can enter bodily and perform work;
Has limited or restricted means of entry or exit;
Is not designed for continuous human occupancy.

Examples of Confined Spaces:

Tanks
Manholes
Boilers
Furnaces
Sewers
Silos
Hoppers
Vaults
Pipes
Trenches
Tunnels
Ducts
Bins
Pits

Potential Hazards in Confined Spaces

Oxygen Deficiency
<19.5% or >23.5% oxygen concentration
Combustibles
Methane
Hydrogen
Acetylene
Propane
Gasoline fumes
Toxic Materials
Carbon Monoxide
Hydrogen Sulfide
Welding fumes
Corrosives
Electricity
Mechanical Hazards
Mixers
Crushers

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

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.
Test the Atmosphere
Check for Oxygen Content:
At least 19.5% and less than 23.5%
Check for Combustibles:
Less than 10% of the LEL
Check for Toxic Gasses:
Most commonly carbon monoxide (PEL <35 ppm)
or any other hazardous materials as determined by the use of the space.

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.

Ventilate the Space

Use mechanical ventilation
Fans
Air horns
Ventilate at the rate of at least four (4) volumes per hour
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.

Categorizing Work Space

Permit-Required Confined Space

A Permit-Required Confined Space is  confined space that has one or more of the following characteristics:
Contains or has the potential to contain a hazardous atmosphere;
Contains a material that has the potential for engulfing an entrant;
Has an internal configuration such that an entrant could become trapped or asphyxiated; or
Contains any other serious safety or health hazard.

Non-Permit Confined Space

A confined space that does not contain or, with respect to atmospheric hazards, have the potential to contain any hazard capable of causing death of serious physical harm.

Two Options for Entering Confined Spaces:

Permit-required confined space entry
For hazardous or potentially hazardous confined space work
Non-permit confined space entry
For non-hazardous confined space work

Permit-Required Confined Space Entry Procedure

Isolate the space
Ventilate the space
Conduct Tailboard
Complete permit
Test the atmosphere
Enter the space

Isolate the Space from all hazards

Close Valves
Double block & bleed, or
Blank flange
Empty the Space
Depressurize, vent & drain
Lockout/Tagout Equipment
Electrical sources
Rotating/reciprocating parts
Hazardous materials
Clean residue from the space

Ventilate the Space

Use mechanical ventilation
Fans
Air horns
Ventilate at the rate of at least four (4) volumes per hour
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.

Conduct a Tailboard Briefing

Entire crew must attend
Attendants, entrants, entry supervisor
Review hazards of entry and work
Review PPE
Review procedure for contacting rescue
verify rescue available
Complete permit
Complete Entry Permit Form
Permit must be correctly and completely filled out prior to entry.
Permit must be activated by Entry Supervisor’s signature to be valid.
No entry is allowed without a valid permit.
Permits are valid for up to 12 hours.
When work is completed, permit and tailboard form should be returned to safety.
Cancelled permits must be kept on file for at least one year.

Test the Atmosphere

Check for Oxygen Content:
At least 19.5% and less than 23.5%
Check for Combustibles:
Less than 10% of the LEL
Check for Toxic Gasses:
Most commonly carbon monoxide (PEL <35 ppm)
or any other hazardous materials as determined by the use of the space.

NOTICE:

Any time a limit is exceeded, no matter what the reason, all personnel shall immediately exit the space, and no others shall enter until atmospheric conditions are returned to safe levels.
Atmosphere Testing Shall Be Performed:
Prior to every entry when the space is vacant;
After a 10 minute ventilation period (if ventilation is necessary);
At least hourly for permit-required confined spaces.
More frequently, if conditions or suspicions warrant.

Enter the Space and Proceed with work:
An attendant shall be posted near the entrance for the duration of the work. He shall be in constant communication with the entrants while the job is in progress.
All entrants shall sign the sign in log when entering the space and sign out when exiting.
The attendant shall maintain the permit and sign in log for the duration of the work.

When the Job is Done:
Remove all personnel, tools, and debris from the space. Sign off the log.
Close the space.
Cancel the permit.
Review the job with the host employer (hazards, problems, other employers, etc.)

Non-Permit Confined Space Entry

Isolate the space
Ventilate the space
Evaluate the space
Test atmosphere
Assure justification conditions are met
Conduct tailboard
Enter the space

Contractor Confined Space Entry

Contractors must be informed of the hazards within the space
Contractors must follow their own established confined space entry procedure and use their own permit forms
Contractors must supply their own attendants
One attendant is acceptable for multiple companies’ entrants
Contractors must supply their own air monitors
Contractors must review entry after completion of job

Entrant Responsibilities

To assure that the space has been adequately ventilated, isolated, emptied, or otherwise made safe for entry.
To immediately exit a space, without question, upon word of the attendant, no matter what the reason.
To follow all safety rules and procedures that apply to the job.
To be familiar with the work to be performed and the procedures that apply to the job.
To use the appropriate PPE whenever necessary.

Supervisor Responsibilities

To assure adequate  protection is provided to the entrants by verifying adequate lockout/tagout and that all hazards are securely isolated.
To support the attendant’s authority in controlling access to a confined space.
To verify that all personnel have exited prior to closing the space.
To assure that all personnel involved are aware of the hazards associated with the space.
To assure that rescue services are available prior to entry.