Confined Space Hazards

1. Confined SpaceHazards

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

3. * Space large enough to enter &; * Limited or Restricted entry or exit &; * Not designed for continuous worker occupancy. NO Not a confined Space YES Confined Space WHAT IS A CONFINED SPACE Let’s take a look at some typical confined spaces

4. Utility Vault Culvert Trenches Manhole Pit Pipes Furnaces Boilers Tunnels Pumping Station Septic Tank Silo Storage Tank Barges Sewer Ducts Typical Confined Spaces

5. What Is... Limited Openings for Entry/Exit • Openings as small as 18 inches in diameter. • Difficult to enter with SCBA or other life-saving equipment. • Difficult to remove downed worker in folded up or bent over position. • Exit from large openings may be difficult due to presence of ladders, hoists, etc.

6. What Is... Unfavorable Natural Ventilation • Lack of air movement in and out of the space can create an atmosphere much different than the outside atmosphere. • Deadly gases can be trapped inside. • Organic materials can decompose. • May not be enough oxygen due to presence of other gases or chemical reactions such as rusting.

7. What Is... Not Designed for Continuous Worker Occupancy • Most confined spaces are not designed to enter and work in on a regular basis. • Designed to store a product. • Enclose materials or processes. • Transport products or substances. • Occasional worker entry for inspection, repair, cleanup, maintenance, etc. Let’s take a look at Permit Required Confined Spaces

8. * Space large enough to enter &; * Limited or Restricted entry or exit &; * Not designed for continuous worker occupancy. NO Not a confined Space YES Confined Space Permit- Required Confined Space Non Permit Required Space Hazardous Atmosphere Or Engulfment Hazard YES NO Or Configuration Hazard Or Any other recognized serious hazard WHAT IS A PERMIT CONFINED SPACE A Permit Confined Space meets the confined space definition In addition, it contains one or more of the following

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

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

11. AsphyxiationIs the Leading Causeof Death in ConfinedSpaces.

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

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

14. 19.5 % Minimum acceptable oxygen level 15 - 19% 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 Oxygen Deficient Atmospheres

15. 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.

16. 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.

17. Carbon Monoxide Odorless, colorless chemical asphxiant / flammable gas / by-product of combustion / quickly collapse at high concentrations PPMEffect 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 5-10 min. 6,400 Headache and dizziness 1-2 min.

18. Hydrogen Sulfide Very strong asphyxiant with rotten egg odor / flammable gas / by-product of the decomposition of organic matter / 4 times heavier than air / possibly no warning at high concentrations PPMEffect Time 10 Permissible Exposure Level 8 hours 50 - 100 Mild Irritation - eyes, throat 1 hour 100 Desensitizes olfactory nerve 2-5 min. 250 - 350 Unconsciousness, death 4-8 hrs. 500 -600 Unconsciousness, death 30-60 min. >1000 Unconsciousness, death minutes

19. 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

20. 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%

21. 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.

22. 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.

23. 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.

24. 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.

25. Testing, Evaluation and Monitoring • Test the atmosphere before entry! • Test in the following order • Oxygen • Combustibles • Toxics • Test for stratified atmospheres as illustrated on next slide • Evaluate: • methods for isolating the space • safe entry procedures • special tools needed • communication equipment needed • Monitor the atmosphere continuously to determine any changes

26. 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

27. IDLH Immediately Dangerous to Life or Health • Any condition which poses an immediate threat to the health of life on an entrant, or; • Would cause irreversible adverse health effects, or; • Would interfere with an individual’s ability to escape unaided from a permit space. All Confined Spaces should be considered IDLH until proven otherwise!

28. 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 Acceptable Atmospheric Conditions

29. 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

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

31. 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.

32. Isolation • Locking and tagging out electrical sources. • Blanking and bleeding pneumatic and hydraulic lines. • Disconnecting mechanical drives and shafts. • Securing mechanical parts. • Blanking sewer and water flow. • Locking and tagging out shutoff valves.

33. Non-Permit Confined Space Entry • Isolate the space • Ventilate the space • Evaluate the space • Test atmosphere • Assure justification conditions are met • Document, Document, Document • Enter the space

34. 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

35. 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.

36. Evaluate the Space • Determine that the space meets all the conditions set forth in the non-permit justifications • Conduct atmospheric testing • Evaluation must be certified by Entry Supervisor’s signature • Determine that the confined space does not: • contain or have the potential to contain a hazardous atmosphere • Continuous mechanical ventilation not acceptable as good atmosphere • contain a material with the potential for engulfment • Has an internal configuration which could trap or asphyxiate, or • contain any recognized serious safety or health hazard

37. Enter the Space and Proceed with work: • If non-permit conditions change during the job, the space shall be immediately evacuated, and re-classified as a permit-required confined space; or conditions shall be returned to non-permit conditions and again certified as such by the entry supervisor.

38. ENTRY • The act by which a person intentionally passes through an opening into a permit required confined space. • Any part of the body passing through the opening is considered entry.

39. QUESTIONS? See your supervisor