2. Confined Space Entry

4. Confined Space
(1) Large enough for an employee to
bodily enter and perform work AND
(2) Has limited or restricted entry or exit
AND
(3) Is not designed for continuous
employee occupancy

5. Permit Required Confined Space
A confined space that:
(1) contains or has a potential to contain a
hazardous atmosphere OR
(2) has the potential for engulfment OR
(3) Has an internal configuration that could trap
or asphyxiate OR
(4) Contains any other recognized serious safety
or health hazard

6. Confined Space Question…
• Why are we entering this space?

7. Limited Or Restricted Entry
• Any space where an occupant
o Must crawl, climb, twist
o Be constrained in a narrow opening
o Follow a lengthy path
o Exert unusual effort to enter or leave
o May become trapped
 Entrance may become sealed or secured
against opening from inside

8. Confined Spaces

9. Hazardous Atmosphere
• Potential exposure to
o Risk of death
o Incapacitation
o Impairment of ability to self-rescue
o Injury
o Acute illness
• If none of the above
o Does not apply to this standard

10. Reclassify
• Reclassify to a non-permit space if
o All potential for a hazardous atmosphere is
eliminated AND
o All other hazards and potential hazards are
eliminated/controlled

11. Air & Oxygen
• Air and oxygen are NOT synonymous.
• Air contains
o 20.9% oxygen
o 78.1% nitrogen
o 1% argon
o Trace amounts of other gases

12. Hazardous Atmosphere
• Flammable gas, vapor, or mist in excess of 10
percent of its lower flammable limit (LFL)
• Airborne combustible dust at a concentration
that meets or exceeds its LFL
o Or visibility 5’ or less

13. Hazardous Atmosphere
• Atmospheric oxygen concentration below 19.5
percent or above 23.5 percent
• Atmospheric concentration of any toxic
substance for which a dose or a permissible
exposure limit is published
• Any other atmospheric condition that is
IMMEDIATELY DANGEROUS TO LIFE OR
HEALTH. (IDLH)

14. Delayed Threat
• Cadmium vapor and hydrogen fluoride
o May seem ok; immediate symptoms
go away
o Fatal 12 to 72 hours later

15. Conditions That Can Cause Oxygen
Deficiency
• Adsorption by porous surfaces
o Activated charcoal
• Consumed by chemical reactions
o Rusting
o Fermentation
• Displaced
o Inert gasses
 Argon
 CO2
 Nitrogen

16. Conditions That Can Cause
Oxygen Enrichment
• Poorly designed or malfunctioning O2
storage or dispensing equipment
• Leaks from oxy-acetylene welding or
cutting equipment
o Couplings, fittings hoses
• Ventilating with pure oxygen

17. Flammable Atmospheres
• Vapor burns, not liquid
• Flammability based on
o Amount of vapor
o Temperature

18. Tank Residue
• Explosions often caused by residue in
“empty” tanks or spaces

19. Residue In Tanks 99% Empty
TANK SIZE (GALLONS)
50,000
40,000
30,000
20,000
10,000
5,000
2,500
1,000
RESIDUE (GALLONS)
500
400
300
200
100
50
25
10

20. Upper & Lower Flammable Limits
AIR100% 0%
GAS
0% 100%
LEAN RICH
EXPLOSIVE
RANGE
LEL UEL

21. Flammable Atmosphere: Propane

22. Flammable Atmospheres

23. Ignition Sources
• Open flame
• Electrical arcing
• Hot surfaces
o Light bulbs
• Static electricity
• Frictional sparks
• Chemical reactions
230o C

24. Control Of Ignition Sources
• Non-sparking tools
• Approved electrical equipment
• Purged & pressurized equipment
• Intrinsically safe equipment
• Explosion proof equipment
• Vessel inerting

25. Control Of Ignition Sources: Hot Work
Precautions
• Hot work permits
• Welding & cutting precautions
o Control of torches & control valves
o Hoses & regulators
 In good condition
 Inspected
 Minimal tape
o Fire prevention & protection

26. Toxic Atmospheres
TOXIC:
• Harmful, destructive
• Deadly
• Poisonous
(THE AMERICAN HERITAGE DICTIONARY)

27. Sources of Toxic Atmospheres
• Products stored in space
• Work being performed in space
o Painting, cleaning & degreasing
o Welding, cutting & brazing
• Adjacent areas
o Toxins enter & accumulate
o Leaching
o Chemicals dumped into sewers,
streams

28. Toxic Gasses
• Irritant Gas
o Serious effects may be delayed
o Examples
 Ammonia, chlorine, sulfur dioxide, ozone,
nitrogen dioxide
• Asphyxiate Gas
o Smothers due to lack of oxygen
o Two classes
 Simple asphyxiates
 Chemical asphyxiates

29. Simple Asphyxiates
Displaces oxygen:
• Acetylene
• Argon
• Ethane
• Ethylene
• Helium
• Hydrogen
• LP gas
• Methane
• Neon
• Nitrogen

30. Chemical Asphyxiates
Cause asphyxiation through biochemical
reaction
• Hydrogen sulfide
• Carbon monoxide
• Hydrogen cyanide

31. Engulfment
"The surrounding and effective capture of
a person" by
• A liquid
• Finely divided (flowable) solid
OR

32. Engulfment
• Quicksand effect
• Material drawn from bottom
• Bridges created by air pockets
Air Pocket

33. Mechanical Hazards
• Manually isolate each piece of
equipment
o Prevent vapor leaks, flashbacks, etc.
• All pipes must be physically
disconnected or isolation blanks bolted
in place
o Closing valves not sufficient
o Inspect & test for leakage
• Also consider steam valves, pressure
lines, chemical transfer pipes

34. Lockout - Tagout
• Render ALL hazardous equipment
related to space inoperable
o Including accidental startup by others
Refer to Lockout/Tagout Standard: 1910.147

35. Control, Isolation Methods
• Lockout/tagout
• Purging
• Block & bleed
• Inerting
• Ventilating
• Flushing

36. Noise
• Noise usually intensified in spaces
o Exposure may be higher than in open
environment
• May disrupt verbal communication
o Especially with attendant

37. Air Testing Instruments
• Many different kinds of instruments
• Results not instantaneous
o Delay for portable instruments 30-60
seconds
• Assure properly calibrated
• Proper care & maintenance
o Per manufacturer

38. Air Testing Instruments
• Understand use & limitations
o Accuracy may be +/- 2%, 5%…
o May be affected by extremes of
temperature
o May be affected by rich CO2 atmosphere
o May only operate properly within certain
temperatures and relative humidity

39. Air Testing
• Test in order
o Oxygen
o Flammables
o Toxins
• Test at various levels
• Test various places
• Continuously monitor
• Test around cover before opening

40. Air
Testing

41. Alarm Devices
• ”Alarm only" devices which do not
provide readings are not acceptable
o For initial (pre-entry) or
o Periodic (assurance) testing
• Not enough information to establish
acceptable entry conditions
• Combination units may be acceptable
o Benefit of automatic alarming at
predetermined value.

42. Ventilation Equipment
• Wide variety of types of ventilation
equipment
o Size & portability
o Air volume capabilities
o Power sources

43. Ventilation Only Entry
Required
• Demonstrate: only hazard is actual or
potential hazardous atmosphere
• Demonstrate: continuous forced air
ventilation alone is sufficient to maintain
safe entry
• Develop monitoring and inspection data
to support these demonstrations

44. Hazard Control Hierarchy
• Eliminate hazard
o Engineering controls
o Process modification
• Substitute less hazardous
o Materials
o Methods
o Techniques
• Personal protective equipment

45. Personal Protective Equipment
• Proper fit
• Cleaning & maintenance
• Replacement
• Proper use
• Will not interfere with movement within
space
• Employee training

46. Respiratory Protection
• Vast selection
o Types, styles
o Limitations
o Specific uses
• Have selection made by qualified
person

47. Permit-required Spaces
General Requirements
• Evaluate:
• Identify all confined spaces
• Evaluate to determine if any spaces are
permit required confined spaces.

48. Permit-required Spaces
General Requirements
• Notify employees of
o Existence
o Location and
o Danger
• Post signs
There, and
there, and over
there...

49. Permit-required Spaces
General Requirements
• If employees will enter permit spaces:
o Develop & implement a written permit
space program

50. Written Program
• Ensure that EVERY confined space is
o Evaluated as a possible permit space
o Reevaluated when its uses or surroundings
change.

51. Entry
“IS CONSIDERED TO HAVE
OCCURRED AS SOON AS ANY PART
OF THE ENTRANT'S BODY BREAKS
THE PLANE OF AN OPENING INTO THE
SPACE”

52. Permit Required Confined Space
Entry Team
• Entrant
• Attendant
• Entry supervisor
• Rescuers

53. Rescuers
• 60% OF CONFINED SPACE VICTIMS
ARE WOULD BE RESCUERS (NIOSH
STUDY)

54. Dial 911 - ?
• Must be informed of hazards
• Must have access to all permit spaces
• Must be trained
• Should be available
o Make arrangements BEFORE need arises

55. Non-entry Rescue
• Use non-entry rescue whenever
possible
• Use retrieval systems or methods
whenever an entrant enters a permit
space
o Unless the retrieval equipment would
increase the overall risk of entry or would
not contribute to the rescue of the entrant

56. Non-entry Rescue
• A mechanical device
must be available for
rescue for vertical
type permit spaces
more than 5 feet
deep.

57. Entry Permit
• Actual document
• Contains specific required information
about entry
• Provides history of entry
• Retain for at least 1 year Enter
space
#12

58. QUESTIONS
????

59. SANDRA A. MIHALIK
Safety & Health Specialist
Montana Safety & Health
Bureau
406.444.6418
e-mail: smihalik@mt.gov