Confined Space Entry

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 • Must crawl, climb, twist • Be constrained in a narrow opening • Follow a lengthy path • Exert unusual effort to enter or leave • May become trapped • Entrance may become sealed or secured against opening from inside

8. Confined Spaces

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

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

11. Air & Oxygen • Air and oxygen are NOT synonymous. • Air contains • 20.9% oxygen • 78.1% nitrogen • 1% argon • 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 • 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 • May seem ok; immediate symptoms go away • Fatal 12 to 72 hours later

15. Conditions That Can Cause Oxygen Deficiency • Adsorption by porous surfaces • Activated charcoal • Consumed by chemical reactions • Rusting • Fermentation • Displaced • 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 • Couplings, fittings hoses • Ventilating with pure oxygen

17. Flammable Atmospheres • Vapor burns, not liquid • Flammability based on • Amount of vapor • 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 AIR 100% 0% EXPLOSIVE RANGE LEAN RICH 0% 100% GAS LEL UEL

21. Flammable Atmosphere: Propane

22. Flammable Atmospheres

23. Ignition Sources • Open flame • Electrical arcing • Hot surfaces • 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 • Control of torches & control valves • Hoses & regulators • In good condition • Inspected • Minimal tape • 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 • Painting, cleaning & degreasing • Welding, cutting & brazing • Adjacent areas • Toxins enter & accumulate • Leaching • Chemicals dumped into sewers, streams

28. Toxic Gasses • Irritant Gas • Serious effects may be delayed • Examples • Ammonia, chlorine, sulfur dioxide, ozone, nitrogen dioxide • Asphyxiate Gas • Smothers due to lack of oxygen • 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 OR • Finely divided (flowable) solid

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

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

34. Lockout - Tagout • Render ALL hazardous equipment related to space inoperable • 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 • Exposure may be higher than in open environment • May disrupt verbal communication • Especially with attendant

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

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

39. Air Testing • Test in order • Oxygen • Flammables • 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 • For initial (pre‑entry) or • Periodic (assurance) testing • Not enough information to establish acceptable entry conditions • Combination units may be acceptable • Benefit of automatic alarming at predetermined value.

42. Ventilation Equipment • Wide variety of types of ventilation equipment • Size & portability • Air volume capabilities • 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 • Engineering controls • Process modification • Substitute less hazardous • Materials • Methods • 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 • Types, styles • Limitations • Specific uses • Have selection made by qualified person

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

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

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

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