Transcript No Slide Title

Subpart J
Confined Spaces
29 CFR 1910.146
Background
• OSHA estimates 239,000 general industry
establishments employing over 12 million
workers have confined spaces
• More than 4.8 million Permit Required Confined
Spaces and millions more non-permit confined
spaces
• Over 30 different industries are affected by the
hazards of confined space entry
• BLS(2002) reports an average of 20 fatalities
per year from confined space hazards
What kills people in confined
spaces?
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They _________ from lack of oxygen.
They are exposed to _________ chemicals.
They are killed by ______ or ________.
They are __________ by cave-ins.
They are __________ by unstable material.
They sustain _______ injuries from falls.
They are ______ __ objects or equipment.
What kills people in confined
spaces?
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They suffocate from lack of oxygen.
They are exposed to toxic chemicals.
They are killed by fire or explosions.
They are crushed by cave-ins.
They are engulfed by unstable material.
They sustain fatal injuries from falls.
They are struck by objects or equipment.
Why?
Why do we have a confined space standard?
–122 confined space accidents each year
lead to 173 fatalities
–60% of the fatalities occurred during
rescue attempts
Why? (continued)
Intended to protect workers from
•toxic, flammable, explosive, or asphyxiating
atmospheres
•possible engulfment
•any other recognized serious hazard (example hazardous energy)
The standard focuses on areas with immediate health
or safety risks, denoting them as “Permit Required
Confined Space”
Chronology of 29 CFR 1910.146
• Advanced Notice of Proposed Rulemaking (ANPR) for
General Industry July 24, 1975 and Oct 19, 1979
• ANPR for Construction Industry March 25, 1980
• Public Meetings held May, 1980 in Houston, Denver and
Washington, D.C.
• General Industry Proposed Standard June 5, 1989
• Hearings held Nov 14 & 15, 1989 in Washington, D.C., Dec 5
& 6, 1989 in Houston and Jan 30 - Feb 1, 1990 in Chicago
• Public Record closed November 9, 1990
• Final Rule published Jan 14, 1993; effective April 15, 1993
• Final Rule changes published December 1, 1998; effective
February 1, 1999
General Industry Standard
• 29 CFR 1910.146
– (a) Scope
– (b) Definitions
– (c) General Requirements
– (d) Permit-Required confined space program
– (e) Permit system
– (f) Entry permit
– (g) Training
General Industry Standard
• 29 CFR 1910.146
– (h) Duties of authorized entrants
– (i) Duties of attendants
– (j) Duties of entry supervisors
– (k) Rescue and emergency services
– (l) Employee participation
General Industry Standard
• 29 CFR 1910.146 Appendices
– Appendix A – Permit-required confined space
decision flow chart
– Appendix B – Procedures for atmospheric
testing
– Appendix C – Examples of permit-required
confined space programs
– Appendix D – Confined space pre-entry
checklist
General Industry Standard
• 29 CFR 1910.146 Appendices
– Appendix E – Sewer system entry
– Appendix F – Rescue team or rescue service
evaluation criteria (non-mandatory)
December 1, 1998 Changes
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Authorized representatives
Observation of testing
Clarified paragraph (k)
Added paragraph (l)
Added Appendix F
Scope and application - (a)
• 29 CFR 1910.146 does not apply to:
– Agriculture
– Construction
– Shipyards
Common Confined Spaces
•Degreaser, Furnace
•Pit, Pumping Station
•Septic Tanks, Sewage Digestors
•Silos, Barges
•Manholes
•Trenches, Shafts
How to Identify Confined Spaces
1.Limited Openings for Entry and Exit; and
2.Is large enough and so configured that an
employee can bodily enter and perform
assigned work; and
3.Not Designed for Continuous Worker
Occupancy
Confined Space Triangle
RESTRICTED
ENTRY/EXIT
NOT DESIGNED FOR
CONTINUOUS
CONFINED
OCCUPANCY
SPACE
LARGE ENOUGH TO ENTER
AND PERFORM WORK
Federal Register
Jan 14, 1993 (p. 4477)
“While OSHA is concerned that
spaces that are too small for
complete bodily entry may pose
hazards for employees, the Agency
did not intend to cover such spaces
under the permit space standard.”
Federal Register
Nov. 4, 1994 (p. 55208)
“Limited - when an employee would be forced to
enter or exit in a posture that might slow selfrescue or make rescue more difficult.”
Standard Safety Requirements for
Confined Spaces (ANSI Z117.1-1995)
“Restricted entry and exit means physical
impediment of the body, e.g., use of the hands
or a contortion of the body to enter into or exit
from the confined space”.
Federal Register
Nov. 4, 1994 (p. 55208)
“For example, even if the door or portal of a
space is of sufficient size, obstructions
could make entry into or exit from the
space difficult. The Agency intended that
spaces which otherwise meet the definition
of confined spaces, and which have
obstructed entry or exits even though the
portal is a standard size doorway, be
classified as confined spaces.”
Questions to Ask
• Does the person have to use their hands to
enter or exit the space?
• Is the person in an awkward posture when
entering or exiting the space?
• Is a person’s entry into or exit from the space
slowed down or impeded by physical
obstructions (such as pipes, ductwork, walls,
holes in the floor, flanges, etc.)?
• Would an employee be forced to enter or exit
in a posture that might slow self-rescue or
make rescue more difficult?
Federal Register
Jan 14, 1993 (p. 4478)
• OSHA believes that the final rule’s
definition properly places the focus on the
design of the space, which is the key to
whether a human can occupy the space
under normal operating conditions.
Worker entered by ladder –
is this a C/S?
Dust Collector
To Underground Tunnel
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
Permit Required Confined Space
1. Contains or has a potential to contain a hazardous
atmosphere;
2. Contains a material that has the potential for engulfing an
entrant;
3. Has an internal configuration such that an entrant could
be trapped or asphyxiated by an inwardly converging
walls or by a floor which slopes downward and tapers to
a smaller cross section; or
4. Contains any other recognized serious safety or health
hazard.
Confined Space VS
1. Limited Openings for
Entry & Egress
2. Large enough to bodily
enter and perform work
3. Not designed for
continuous worker
occupancy
Permit Required
Confined Space
1. Hazardous atmospheres
2. Engulfment
3. trapped or asphyxiated by
an inwardly converging
walls or by a floor
4. Contains any other
recognized serious safety or
health hazard
Hazardous Atmosphere
• Means an atmosphere that may expose
employees to the risk of death, incapacitation,
impairment of ability to self-rescue (escape
from a permit space), injury, or acute illness
from one or more of the following causes:
Hazardous Atmosphere
1. Flammable gas, vapor, or mist in excess of 10% of its
lower flammable limit (LFL);
2. Airborne combustible dust at a concentration that meets
or exceeds its LFL;
3. Atmospheric oxygen concentration below 19.5% or
above 23.5%;
4. Atmospheric concentrations of any substance for which a
dose or PEL is published in Subpart G or Z of this Part
and which could result in employee exposure in excess of
its dose or PEL;
5. Any other atmospheric condition that is IDLH
Evaluation – (c)(1)
•Employers are required to evaluate workplaces
to determine if any spaces are PRCS
•* Proper application of the decision flow chart
in Appendix A would facilitate compliance with
this requirement
Categorizing Work Space
* Space large enough to enter &;
* Limited or Restricted entry or exit &;
* Not designed for continuous worker
occupancy.
YES
PermitRequired
Confined
Space
NO
Not a confined Space
Confined Space
Hazardous Atmosphere
YES
Or
Engulfment Hazard
Or
Configuration Hazard
Or
Any other recognized
serious hazard
Non
NO
Permit
Required
Space
Signs - (c)(2)
• Employees must be informed of the
existence of confined spaces through the
use of signs, etc.
UNAUTHORIZED ENTRY
MUST BE PREVENTED
Signs – (c)(2)
A sign reading:
- DANGER PERMIT REQUIRED CONFINED SPACE
“DO NOT ENTER”
or other similar language would
satisfy the requirement for a sign.
Ensure No Entry – (c)(3)
• If employees will not enter permit spaces,
the employer will take effective measures to
prevent them from entering
•Required to Still comply with paragraphs
(c)(1), (c)(2), (c (6), and (c)(8)
Entering Permit Spaces – (c)(4)
• If employees will enter permit spaces, the
employer shall develop and implement a
written permit space program
•The written program shall be available for
inspection by employee and their
authorized representatives
“Changes” - (c)(6)
When there are changes in the use or
configuration of a non-permit confined
space that might increase the hazards to
entrants, the employer shall reevaluate that
space and, if necessary, reclassify it as a
permit-required confined space.
Host Employers – (c)(8)
(i) Inform contractor workplace contains permit
spaces and that entry is only allowed through
compliance with a permit system
(ii) Appraise the contractor of the elements,
including hazards identified and employer’s
experience with the space
(iii) Appraise the contractor of any precautions
or procedures that have been implemented for
the protection of employees in or near the
spaces where the contractor will be working
Host Employers – (c)(8)
(iv) Coordinate entry operations with
contractor, when both host employer personnel
and contract personnel will be working in or
near permit spaces
(v) Debrief contactor at conclusion of the entry
operations regarding the program followed and
any hazards confronted or created in the
permit spaces during entry operations
Contractor – (c)(9)
(i) Obtain any available information regarding
permit space hazards and entry operaitons
(ii) Coordinate entry operations with host
employer
(iii) Inform the host employer of any hazards
confronted or created in permit spaces, either
through debriefing or during entry operations
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 %
15 - 19%
12-14%
10-12%
8-10%
6-8%
4-6%
Minimum acceptable oxygen level.
Decreased ability to work strenuously.
Impair coordination. Early symptoms.
Respiration increases. Poor judgment.
Respiration increases. Lips blue.
Mental failure. Fainting. Nausea
Unconsciousness. Vomiting.
8 minutes - fatal, 6 minutes - 50% fatal
4-5 minutes - possible recovery.
Coma in 40 seconds. Death
Oxygen Deficient
Atmospheres
• Exposure to atmospheres containing 12%
or less oxygen will bring about
unconsciousness without warning and so
quickly that individuals cannot help or
protect themselves.
(Source: Compressed Gas Association Bulletin SB-2)
Primary Constituents of Normal
Air
(Permanent Gases)
Chemical Molecular Percent
Constituent Formula Weight by Volume
Nitrogen
N2
28
78.1
Oxygen
O2
32
20.9
Argon
Ar
40
0.9
Water vapor content varies, but is usually the third largest
constituent by volume in air.
Oxygen Enriched
Atmospheres
• Oxygen level above 23.5%.
• Causes flammable and combustible
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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
• The byproducts of
work procedures
can generate
flammable or
explosive
conditions within a
confined space.
Flammable Hazards Definitions
• Lower Flammable Limit
– Minimum concentration of vapor or gas in air
below which propagation of flame does not
occur on contact with a source of ignition (below
the LFL there is too little combustible fuel to
sustain a flammable mixture)
Flammable Hazards Definitions
• Upper Flammable Limit
– Maximum concentration of vapor or gas in air
above which propagation of flame does not
occur on contact with a source of ignition (above
the UFL there is too little oxygen to sustain a
flammable mixture)
Flammable Atmospheres
• 3 Critical Factors:
– Presence of a flammable gas, or vapor
– Presence Oxygen content in the air.
– 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.
Simple Asphyxiants
- gases that causes suffocation by dilution of
oxygen.
• Nitrogen (N2)
• Argon (Ar)
• Methane (CH4) - also
Inerting
• 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
Nitrogen (N2)
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Colorless, odorless inert gas
Slightly lighter than air
Used for inerting
Non flammable
Non reactive
Simple asphyxiant
Argon (Ar)
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Colorless, odorless inert gas
Heavier than air
Used for inerting
Simple asphyxiant
Used as a shielding gas in welding
Methane (CH4)
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Natural, marsh, swamp gas
Colorless, odorless gas
Lighter than air
Flammable gas (LEL = 5%; UEL = 15%)
Simple asphyxiant
Product of organic decay
Chemical Asphyxiants
- materials that render the body incapable of
utilizing an adequate supply of oxygen.
Examples include:
• Carbon monoxide
• Hydrogen sulfide
Hydrogen Sulfide
• Decomposition of materials. Human waste.
• Rotten egg odor at low concentrations.
• Causes olfactory fatigue
• Odor threshold: 0.02 - 0.2 ppm
PPM
10 ppm
50 - 100
200 - 300
500 -700
>1000
Effect
Permissible Exposure Level
Mild Irritation - eyes, throat
Significant Irritation
Unconsciousness, Death
Unconsciousness, Death
Time
8 Hours
1 Hour
1 Hour
1/2 - 1 Hour
Minutes
Carbon Monoxide
• Odorless, Colorless Gas.
• Combustion By-Product.
• Quickly collapse at high concentrations.
PPM
Effect
50
200
600
1000-2000
1000-2000
1000-2000
2000-2500
Permissible Exposure Level
Slight headache, discomfort
Headache, discomfort
Confusion, nausea, headache
Tendency to stagger
Slight heart palpitation
Unconsciousness
Time
8 Hours
3 Hours
1 Hour
2 Hours
1 1/2 Hours
30 Min.
30 Min.
Confined space testing
FOUR-GAS DETECTOR
•Oxygen content
•Flammability / explosion
potential
•Carbon monoxide
•Hydrogen sulfide
CRITICAL ISSUES
•Training
•Procedures
•Calibration
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
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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.
Determination of Purge Time
! Purge times can be estimated by the
following:
T = 7.5 V/C
T = purge time in minutes
V = the volume of the space in ft3
C = effective blower capacity CFM
Purging Time Example
Situation:
An estimation of purging time is needed for a
800 ft3 deep neck manhole. The effective
blower capacity is 250 CFM
800/250 x 7.5 = 24 minutes
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.
Respirators for IDLH
Atmospheres
Full Facepiece
Pressure Demand
SCBA
Combination Full Facepiece
Pressure Demand SAR with
Auxiliary Self-Contained Air
Supply
Isolation
• Locking and tagging out electrical sources.
• Blanking and bleeding pneumatic and
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hydraulic lines.
Disconnecting mechanical drives and
shafts.
Securing mechanical parts.
Blanking sewer and water flow.
Locking and tagging out shutoff valves.
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
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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.
Authorized Entrants
Entrants must:
• know the hazards they are facing
• be able to recognize signs and symptoms of
exposure
• understand the consequences of exposure to
hazards
• communicate with attendants as necessary
• alert attendants to warning signs or existence
of a hazardous condition
• exit when ordered oar alerted
Attendants
Attendants must:
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be aware of behavioral effects of potential
exposures
maintain count and identity of entrants
remain outside the space until relieved
communicate with entrants
monitor activities inside and outside the space
and order exit if required
Attendants (cont)
Attendants must:
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Summon rescuers is necessary
prevent unauthorized entry
perform non-entry rescue
Attendants may NOT perform other duties
that interfere with their primary duty
to monitor and protect!
Entry Supervisors
Entry Supervisors must:
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issue confined space permits
know hazards
verify that all tests have been conducted
verify that all procedures and equipment are
in place before signing a permit
terminate entry if necessary and cancel
permits
Entry Supervisors (cont)
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•
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Verify availability of rescue services
and means for summoning them
remove unauthorized individuals,
terminate entry if necessary, and
cancel permits
coordinate shift change
Permit Entry Systems
• Written permit signed by entry supervisor.
• Verifies pre-entry precautions have been
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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
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•
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:
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–
–
–
Job duties change.
Change in permit-space program.
New hazards are present.
Job performance indicates deficiencies.
Training and Education
• Training and emergency drills should be
•
conducted once a year or whenever the
procedure or process changes
Records for training must include:
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–
–
–
name of employee(s)
signature of trainer(s)
date(s) of training and
must be retained for 3 years
Alternative Protection Procedures
OSHA has specified alternative protection
procedures that may be used for permit
spaces where the only hazard is
atmospheric and ventilation alone will
control the hazard.
Entry Without Permit (continued)
When a confined space is opened
– the opening must be promptly guarded by a
rail or temporary cover
– the atmosphere must be tested before
entering using only direct reading instruments
– the atmosphere must be tested (in this order)
for oxygen content, flammable
gasses/vapors, and toxic air contaminants
– continuous forced air ventilation must be
used
Entry Without Permit (continued)
When a confined space is opened
– the atmosphere must be tested
periodically during work
– the employer must verify alternative
procedure applicability and safe entry
conditions by a written certification (not a
permit) with the following information:
1. date
NOTE: The above certificate must
2. location
be made available to entrant to
review.
3. signature
Entry Without Permit (continued)
If you meet the conditions stated in Section
(C)(5)(I) of the OSHA standard, you may
use the procedures specified in Section
(C)(5)(ii) of the standard.
This allows you to OMIT
Paragraphs (d) through (f)
and (h) through (k) of the standard.
NOTE: Paragraph (g) Training
still applies to all confined
space activities
RESCUE
The Necessity of Rescue
• Entrants are in spaces that could
quickly render them unconscious
• Over 60% of fatalities in confined
spaces are would-be rescuers
• A pre-planned and effectively executed
rescue saves lives
• Entry programs that by-pass safeguards
will eventually end up requiring rescue
Types of Rescue
• Self-Rescue
• Non-Entry Rescue
• Entry Rescue
Self Rescue
• Initiated by entrant
or attendant
• Worker removes self
• No rescuer entry
required
• Entrant must know
reasons for self
rescue
Non-Entry Rescue
• Entrant must wear full
body harness and be
attached to a retrieval
system
• Usually initiated by
attendant
• Difficult when equipment
entangles lines
• Difficult when entrant is
not directly in line of sight
or is around obstacles
Entry Rescue
• Most difficult and
risky
• Requires training,
equipment and
coordination of efforts
Rescue Members are Trained:
• To perform assigned
duties
• As entrants
• In first aid and CPR (at
least one member holds
current certification)
• To be proficient in use of
personal protective
equipment
• To practice rescue at
least once every 12
months
Rescue Equipment Components
Body
Support
Connecting
Component
Anchorage
Component
Anchorage
Tripod with Hoist and Rope
Davit Arm
Vehicle-Mounted Davit
Wall Mount Support
Structure Mounted Rope
and Pulley System
Horizontal Retrieval Support
Employer Responsibilities
• Evaluate prospective rescue
team abilities to respond in a
timely manner.
• Ensure the rescue team is
trained and equipped to
execute a rescue
• Provide the rescue team access
to the permit spaces
• Ensure rescue is practiced at
least once every 12 months
• Non-mandatory Appendix F
may be used as a guide to
evaluate rescue teams
Rescue Services
• May be provided by
– “on-site” employees
– “off-site” services
On-site Teams
On-site teams must
– be properly equipped
– receive the same training as entrants
– receive additional training in the use of
PPE and rescue equipment and in first aid
and CPR
– practice simulated rescues once each year
Off-site Teams
Off-site teams must
– be aware of
confined space
hazards
– practice similar
rescues in similar
spaces
Questions?