PowerPoint Presentation On HAZARDOUS ATMOSPHERES

PPT On HAZARDOUS ATMOSPHERES

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1. 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

2. 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

3. 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

4. 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)

5. PERMISSIBLE EXPOSURE LIMIT (PEL)
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

6. 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

7. CONFINED SPACE CHARACTERISTICS
Large enough for worker to enter
Contains or can contain hazardous atmosphere produced by sludge, chemicals, sewage
Laid out so anyone who enters may be trapped or asphyxiated

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

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

10. Common Shipboard Hazards
Carbon Monoxide
Hydrogen Sulfide
Halon & Freon
Carbon Dioxide
Nitrogen Dioxide
Methane
Hydrogen
Ammonia

11. What Toxic Tests are required to be conducted after a class "B" fire?
Carbon Dioxide
Carbon Monoxide
Hydrogen Chloride
Hydrogen Cyanide
Hydrocarbons

12. Carbon Monoxide (CO)
FROM INCOMPLETE COMBUSTION
COLORLESS, ODORLESS, TASTELESS
LIGHTER THAN AIR
SUBTLE ASPHYXIANT
FLAMMABLE

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

14. 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

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

16. 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

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

18. Nitrogen Dioxide (NO2)
DARK BROWN, PUNGENT GAS
CHOKING AGENT -- Absorbed
HEAVIER THAN AIR
NON FLAMMABLE

19. Methane (CH4)
COLORLESS, ODORLESS GAS
LIGHTER THAN AIR
EXTREMELY EXPLOSIVE
AEROBIC ORGANIC DECAY
20. Ammonia (NH3)
PUNGENT ODOR
LIGHTER THAN AIR
FLAMMABLE
CHOKING AGENT

21. Hydrogen (H)
ODORLESS, COLORLESS GAS
LIGHTER THAN AIR
EXTREMELY EXPLOSIVE

22. HYDROCARBONS
C METHANE
C-C BUTANE
C-C-C-C-C PENTANE
C-C-C-C-C-C-C-C OCTANE

23. 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

24. 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)

25. 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)

26. UNITY EQUATION
DETERMINE IF THE COMBINED TOXIC EFFECTS OF THE FOLLOWING GASES EXCEEDS THE ALLOWABLE PERMISSIBLE EXPOSURE LIMIT ON A TWA.
ACTUAL PEL
Toluene 80 ppm 200 ppm
Carbon Monoxide 25 ppm 50 ppm
Xylene 40 ppm 100 ppm
(Remember, C1/T1 + C2/T2 + ... = 1)

27. UNITY EQUATION
ACTUAL PEL
Toluene 80 ppm 200 ppm
Carbon Monoxide 25 ppm 50 ppm
Xylene 40 ppm 100 ppm

28. 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

29. Thanks