1. Confined Space Hazards

2. We Will Discuss: Types of confined spaces Confined space hazards
Physical reactions to atmospheric hazards
Methods of eliminating or controlling hazards

3. Typical Confined Spaces
Utility Vault
Culvert
Trenches
Manhole
Pit
Pipeline
Pumping Station
Septic Tank
Silo
Storage Tank
Barges
Sewer

4. General Safety Hazards
Mechanical hazards
Communication problems
Entry and exit
Physical
Thermal effects
Noise
Vibration
General / physical
Surface residues
Structural hazards
Fall hazards
Engulfment hazards

5. Atmospheric Hazards Oxygen Deficient Atmospheres
Less than 19.5% by volume
Oxygen Enriched Atmospheres
Greater than 23.5% by volume
Flammable Atmospheres
Toxic Atmospheres

6. Asphyxiation Is the Leading Cause of Death in Confined Spaces.

7. Oxygen Deficiency Can Be Caused by CONSUMPTION.
“Hot work”
Breathing
Chemical reactions (ex. Oxidation of chemicals or metal)
Biological action (ex. Decomposing organic matter)

8. Oxygen Deficiency Can Be Caused by DISPLACEMENT.
Argon
Nitrogen
Helium
Carbon monoxide, carbon dioxide
Cleaning agents, adhesives, or other chemicals

9. Oxygen Deficient Atmospheres
19.5 % Minimum acceptable oxygen level
% Decreased ability to work strenuously, Impaired coordination
12-14% Respiration increases, Impaired judgment
10-12% Resp. increases, poor judgment, lips blue
8-10% Mental failure, fainting, unconsciousness, nausea and vomiting
6-8% 8 minutes – 100% fatal / 6 minutes - 50% fatal / 4-5 minutes - possible recovery
4-6% Coma in 45 seconds, death

10. Oxygen Enriched Atmospheres
Oxygen level above 23.5%.
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.

11. 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.

12. Carbon Monoxide
Odorless, colorless chemical asphyxiant / flammable gas / by-product of combustion
PPM Effect Time
35 Permissible Exposure Level 8 hours
200 Slight headache, discomfort 2-3 hours
400 Headache and nausea 1-2 hours
800 Headache, dizziness, nausea 45 min.
1,600 Headache, dizziness, nausea 20 min.
3,200 Headache and dizziness min.
6,400 Headache and dizziness 1-2 min.

13. Hydrogen Sulfide
Very strong asphyxiant w/ rotten egg odor / flammable gas / by-product of the decomposition of organic matter / 4 times heavier than air
PPM Effect Time
10 Permissible Exposure Level 8 hours
Mild Irritation - eyes, throat 1 hour
100 Desensitizes olfactory nerve 2-5 min.
Unconsciousness, death hrs.
Unconsciousness, death min.
>1000 Unconsciousness, death minutes

14. Flammable Atmospheres
Critical Factors:
Oxygen content in the air.
Flammable gases or vapors
Flammable 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

15. Lower Explosive Limit vs. Upper Explosive Limit
AIR
COMBUSTIBLE
TOO LEAN TO BURN
EXPLOSIVE RANGE
TOO RICH TO BURN
LEL
UEL
Gasoline
1.4% Flammable range 7.6% by volume 0%
100% 0%
100% LEL

16. Causes of Fatalities in Confined Spaces
65% Hazardous atmospheres
13% Engulfment
7% Struck by falling objects
6% Heat stress / exposure
5% Electrocution
4% All others

17. Common Factors in Confined Space Fatalities
Failure to recognize a confined space
Failure to recognize the hazards involved in confined space entry
Tendency to trust physical senses
Tendency to under-estimate the danger.
Complacent attitude
Attempt to save a co-worker

18. All Confined Space Fatalities Occur
Approximately 60% of
All Confined Space Fatalities Occur
Among
Would Be Rescuers!!

19. Confined Space Fatalities Can Be Avoided Through
Confined space safety training
The implementation of a systematic approach to confined space entry

20. 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.

21. Systematic Approach 1. Recognition
2. Testing, evaluation and monitoring
3. Control

22. Recognition 1. Is this a confined space?
2. Is it a permit required confined space?
3. What are the hazards associated with this space?

23. Testing, Evaluation and Monitoring
Test the atmosphere before entry!
Evaluate:
methods for isolating the space
safe entry procedures
special tools needed
communication equipment needed
Monitor the atmosphere continuously to determine any changes

24. Testing The Atmosphere 1910.146 App. A
Evaluation testing
Verification testing
Test for at least the minimum response time of the instrument
Order of testing
Oxygen
Combustibles
Toxics
Stratified atmospheres

25. Always test the air at various levels to be sure that the entire space is safe.
Good Air
Poor Air
Good air near the opening does NOT mean there is good air at the bottom!
Deadly Air

26. IDLH Immediately Dangerous to Life or Health
All Confined Spaces should be considered IDLH until proven otherwise!

27. Acceptable Atmospheric Conditions
Oxygen concentration
Flammable gas, vapor, or mist
Toxic gas, vapor, or mist
19.5% to 23.5%
below 10% of the products LEL
below the PEL of the product

28. Approximately 1/3rd of All Confined Space Fatalities Occur After the Space Has Been Tested Safe for Entry.

29. Control Ventilation Isolation PPE / Respirators Stand-by rescue
Entry permitting