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7.3

7.3. HAZARDOUS. ATMOSPHERES. www.powerpointpresentationon.blogspot.com. ENABLING OBJECTIVES. DESCRIBE the hazards of flammable or toxic gases and vapors. DESCRIBE the physical characteristics of common gases, solvents and fuels.

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7.3

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  1. 7.3 HAZARDOUS ATMOSPHERES www.powerpointpresentationon.blogspot.com

  2. ENABLING OBJECTIVES • DESCRIBE the hazards of flammable or toxic gases and vapors. • DESCRIBE the physical characteristics of common gases, solvents and fuels. • DESCRIBE shipboard locations of various explosive or toxic gases or mixtures of gases may be encountered. • DESCRIBE the sources of explosive or toxic gases in the shipboard environment. • Calculate the combined toxicity levels for combined concentrations of harmful gases

  3. 7.02 HAZARDOUS ATMOSPHERES REFERENCES: (a) 29 CFR 1910.1000, OSHA Permissible Exposure limits (b) NWP 3-20.31, Surface Ship Survivability OPNAVINST 5100.19 (series), NAVOSH Program Manual for Forces Afloat (c) NSTM 074 Vol. 3, Gas Free Engineering

  4. WHY ARE TERMS AND DEFINITIONS IMPORTANT? • You, the GFE, must be able to use and understand terms • Prevents misunderstandings between you, military personnel, and civilian personnel (think liability!) • Lends credibility to your qualifications and your program

  5. IMMEDIATELY DANGEROUS TO LIFE OR HEALTH (IDLH) • Any atmosphere that meets one or more of the following conditions • Oxygen content < 19.5 or > 22% • Flammable vapors at a concentration of 10% or > LEL • Presence of toxicants above NIOSH IDLH limits (Found in Appendix G of 074 Vol. 3)

  6. The maximum permissible concentration of a toxic agent to which personnel may be exposed. Published by OSHA Based on a TWA for a normal 8-hour day, 40 hour, 7-day week Expressed in parts per million (ppm) Single toxicants only PERMISSIBLE EXPOSURE LIMIT (PEL)

  7. CONFINED SPACE • Limited and restricted accesses • Lack of natural ventilation • May contain or produce hazardous contaminants or oxygen deficiencies or enrichment • Not intended for continuous occupancy

  8. CONFINED SPACES • Tanks • Voids • Interior machinery (boilers, condensers, oil sumps) • Non-ventilated storerooms • Ventilation & Exhaust ducts

  9. Gas Free Engineers: O E T What Are You Testing For? OXYGEN EXPLOSIVES TOXICANTS

  10. OXYGEN 22 % 20.9 % 19.5 % 12 % 10 % 8 % 6 % 4 % Normal at Sea Level

  11. OXYGEN 22 % 20.9 % 19.5 % 12 % 10 % 8 % 6 % 4 % Wide Awake, Hyper Vigilant

  12. OXYGEN 22 % 20.9 % 19.5 % 12 % 10 % 8 % 6 % 4 % > 26 % O2, Spontaneous Combustion Can Occur >22 % Oxygen is Considered IDLH Due to Exceptional Risk of Fire

  13. OXYGEN 22 % 20.9 % 19.5 % 12 % 10 % 8 % 6 % 4 % Loss of Coordination, Loss of Perception, Lack of Judgment < 19.5 % Oxygen Considered IDLH by OSHA -- Entry Requires CO’s Permission

  14. OXYGEN 22 % 20.9 % 19.5 % 12 % 10 % 8 % 6 % 4 % Blue Lips, Disorientation

  15. OXYGEN 22 % 20.9 % 19.5 % 12 % 10 % 8 % 6 % 4 % Vomit

  16. OXYGEN 22 % 20.9 % 19.5 % 12 % 10 % 8 % 6 % 4 % Unconscious 5 min : Could recover 6 min: 50% Fatal 8 min: 100% Fatal

  17. OXYGEN 22 % 20.9 % 19.5 % 12 % 10 % 8 % 6 % 4 % Coma in 40 Seconds

  18. OXYGEN 22 % 20.9 % 19.5 % 12 % 10 % 8 % 6 % 4 % Just Remember . . . Oxygen Levels Greater than 22% or Less than 19.5% are IDLH ! X X Death

  19. Reasons for Oxygen deficiency • Eductors • Fires • Rusting (Oxidation) • Inerting • Decomposing Organic Matter • -- Sewage • -- Fermentation of grains, sugars, etc. • -- Rotting plant or marine life

  20. EXPLOSIVES Greater Than 10% LELis ConsideredIDLH -- andRequires CO’s Permissionfor Entry Levels Near LEL Leave No Buffer for Explosive Gas Build-Up Too Rich UEL Explosivity Explosive Range LEL Too Lean 10% % Vapor Concentration

  21. Toxic Gas Common Shipboard Hazards Carbon Monoxide Hydrogen Sulfide Halon & Freon Carbon Dioxide Nitrogen Dioxide Methane Hydrogen Ammonia

  22. What Toxic Tests are required to be conducted after a class "B" fire? Carbon Dioxide Carbon Monoxide Hydrogen Chloride Hydrogen Cyanide Hydrocarbons As Per NSTM 555-7.10.3

  23. Carbon Monoxide (CO) #1 Killer of Sailors FROM INCOMPLETE COMBUSTION COLORLESS, ODORLESS, TASTELESS LIGHTER THAN AIR SUBTLE ASPHYXIANT FLAMMABLE P-100s, Post-Fire Atmosphere, Diesel Generators, Paint Drying Where Onboard Ship?

  24. Hydrogen Sulfide (H2S): #2 Killer of Sailors ORGANIC DECAY COLORLESS GAS ROTTEN EGG SMELL HEAVIER THAN AIR FLAMMABLE Attacks Nerves: Apnea, Coma Anaerobic Organic Decay WHERE H2S HIDES: FIREMAIN AFFF SYSTEM ROTTING FOOD GARBAGE GRINDER SEWAGE SPACES

  25. AEROBIC: (with oxygen) decomposition and stabilization. ANAROBIC: (without oxygen) decomposition.

  26. FREON(R-12, R-113, R-134) Colorless, Odorless, Heavier Than Air NON-FLAMMABLE: RUSSIA USES FREON FOR F/F Frostbite Blunt Asphyxiant, Attacks Nervous System, Dry Land Drowning Phosgene Reefer Decks, A/C Plants

  27. HALON 1301 (BromoTriFlouroMethane) Colorless, Odorless 5 Times Heavier Than Air Frostbite Attacks Nervous System, Dry Land Drowning Decomposes at High Temps: HF, HCl, HBr

  28. HALON 1301 5 - 7 % for 10 min: No Health Danger 7 - 10% : Dizziness, Tingling Extremities, Mild Anesthesia > 10 % : Very Dizzy, Nearly Unconscious, Lose Physical & Mental Dexterity

  29. Carbon Dioxide (CO2) Colorless, Odorless, Tasteless, Inert HEAVIER THAN AIR Blunt Asphyxiant NON-FLAMMABLE Portable CO2 CO2 Flooding

  30. Nitrogen Dioxide (NO2) • DARK BROWN, PUNGENT GAS • CHOKING AGENT -- Absorbed • HEAVIER THAN AIR • NON FLAMMABLE Smoldering Polyester, Wool & Nylon Tank Pressed Up & Heated Produced From Hot Work, Fires, & Internal Combustion Engines

  31. Methane (CH4) COLORLESS, ODORLESS GAS LIGHTER THAN AIR EXTREMELY EXPLOSIVE AEROBIC ORGANIC DECAY

  32. Ammonia (NH3) PUNGENT ODOR LIGHTER THAN AIR FLAMMABLE CHOKING AGENT CLEANING PRODUCTS, URINALS

  33. Hydrogen (H) ODORLESS, COLORLESS GAS LIGHTER THAN AIR EXTREMELY EXPLOSIVE LEAD-ACID BATTERIES RUST

  34. HYDROCARBONS C METHANE C-C BUTANE C-C-C-C-C PENTANE C-C-C-C-C-C-C-C OCTANE BENZENE TOLUENE XYLENE Finding Hydrocarbons Fuel Vapors Paints Solvents

  35. How do you know what toxicants to test for in a space? Appendix E How do you know what Draeger Tubes are available? Appendix L How do you know the PEL and IDLH limits for Toxicants? Appendix G

  36. Supplied Air Respiratorin pressure demand mode (SCBA) or Supplied Air Respirator (SAR)w/ 15 minute backup Air (SCBA) Required IDLH Respiratory Protection Mandatory (Filter Type Respirator or Supplied Air Respirator as Appropriate) PEL Respiratory Protection Optional

  37. UNITY EQUATION “If there is more than one toxicant product in a space undergoing testing, the cumulative effects of the two or more products may be above unity, even though the PELs for any one of the products has not been exceeded.” NSTM 074-19.11 (p74-14)

  38. UNITY EQUATION C1/T1 + C2/T2 + ... = 1 WHERE: C is the Measured Concentrations of Toxic Substances and T is the Toxic Limit : PEL or TLV (whichever is lowest)

  39. UNITY EQUATION DETERMINE IF THE COMBINED TOXIC EFFECTS OF THE FOLLOWING GASES EXCEEDS THE ALLOWABLE PERMISSIBLE EXPOSURE LIMIT ON A TWA. ACTUALPEL Toluene 80 ppm200 ppm Carbon Monoxide25 ppm50 ppm Xylene40 ppm100 ppm (Remember,C1/T1+ C2/T2 + ... = 1)

  40. UNITY EQUATION 80 25 40 + + = 200 50 100 ACTUALPEL Toluene 80 ppm200 ppm Carbon Monoxide25 ppm50 ppm Xylene40 ppm 100 ppm Ce/Te +Ct/Tt+Cn/Tn < 1 .4 + .5 + .4= 1.3 1.3 > 1 SO IT EXCEEDS LIMIT Therefore, Respiratory Protection is Mandatory

  41. Questions???? • SUMMARY – We described the hazards of flammable or toxic gases and vapors. • We described the physical characteristics of common gases, solvents and fuels. • We described shipboard locations of various explosive or toxic gases or mixtures of gases may be encountered. • We described the sources of explosive or toxic gases in the shipboard environment. • We calculated the combined toxicity levels for combined concentrations of harmful gases

  42. REVIEW Questions - When is the Oxygen Level Considered IDLH? Greater than 22%, Less than 19.5% When are Explosives Considered IDLH? Greater than 10% LEL Name 4 Toxicants that are HEAVIER than Air: CO2, H2S, HALON, FREON Name 3 Toxicants which are LIGHTER than Air: CO, Ammonia, Hydrogen, Methane Name 2 Toxicants that can Cause a Sailor to Choke: Nitrogen Dioxide, Ammonia

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