Manure Storage System Safety

1. Manure Storage System Safety 2007 Livestock Manure Management Conference Series

2. Safety issues • Pits and other confined spaces • Lagoons, holding ponds, and other outdoor storages

3. What kinds of events… • Would make you (or your family) say “…if only….” • Would make people of your community shake their heads in horror… • Would leave you with no one to blame but yourself…

4. Session goals • Assess farm for manure storage safety hazards • Become familiar with confined space entry procedures • Learn about ongoing research that may make it easier and less expensive to manage entry hazard

6. Calls Extension Gets • Some slats over a pit broke. I need to: • inspect the rest of the slats • Retrieve carcasses from the pit • Retrieve equipment from the pit • There is excessive foam on the pit. What can I do? • At issue: safety due to engulfment of animals above the slats; and fire/explosion from methane.

7. Livestock Waste StorageConfined Space Entry Procedures

8. The Hazards

10. The hazard seriousness level is usually dictated by... • Type of material stored in the confined space. • The activity carried out in the confined space (i.e. agitation of manure resulting in release of gases). • The external environment (a tank located near rising waters).

11. Confined Space Hazards • Chemical Hazards • Physical Hazards (agitators etc.) • Biological Hazards (manure) • Ergonomic Hazards (no quick exit means)

12. Confined Space Defined • Large enough and configured such that an employee can enter and perform assigned work • Has limited or restricted means for entry or exit (e.g., tanks, vessels, silos, storage bins, hoppers, vaults, & pits)

13. Confined Space Defined • Is not designated for continuous occupancy • Contains or has potential to contain a hazardous atmosphere (toxic, low levels of oxygen etc.)

14. Confined Space Defined • Contains a material that has the potential for engulfment (i.e. liquid manure) • Internal configuration of inwardly converging walls or sloping and tapering floor (i.e. many pits) • Contains any other recognized serious safety or health hazard (i.e. fine dust particles,)

15. Engulfment Characteristics • Surrounding and capture of a person • Liquid or finely divided (flowable) solid • Can cause filling or plugging of respiratory system by aspiration • Can exert enough force on body to cause death by strangulation, constriction, or crushing

16. Confined Space Environment Potential • Immediate or delayed threat to life • Causes irreversible adverse health effects • Interferes with the ability to escape from a space (toxic gases, low oxygen levels etc.)

17. Immediate Danger to Life or Health (IDLH) Conditions • Flammable Gas, Vapor, or Mist >10% of LFL (LEL) • Airborne Combustible Dust > LFL Dust obscures vision at a distance of 5 ft., or less • Oxygen < 19.5 % or > 23.5% • Exposures of gases, dust levels toxicity levels in excess of Personal Exposure Limits (Recognized by OSHA & NIOSH)

18. Primary Constituents of Normal Air(Permanent Gases) Molecular Weight Percent by Volume Chemical Formula Constituent Nitrogen N2 28 78.1 Oxygen O2 32 20.9 Argon Ar 40 0.9 Water vapor content varies, but is usually the third largest constituent by volume in air.

19. Oxygen Oxygen Enriched 23.5% Oxygen Deficient 19.5% Minimum for Safe Entry Impaired Judgment & Breathing 16.0% 14.0% Faulty Judgment Rapid Fatigue 6.0% Difficulty in Breathing Death in Minutes

20. Explosive Limits Too Rich UEL Combustible LEL 10% of LEL Too Lean

21. Methane (CH4) • Natural, marsh, swamp gas • Colorless, odorless flammable gas • Lighter than air • Toxic? • LEL = 5% • UEL = 15%

22. Carbon Dioxide (CO2) • Colorless, odorless noncombustible gas • Heavier than air • Organic decay (grain elevators, livestock waste, storage bins, wells) • Fermentation (digesters, molasses pits, beer and wine vats)

23. Carbon Dioxide (CO2) • PEL = 5,000 ppm - TWA • TLV/REL = 5,000 ppm - TWA; 30,000 ppm - STEL • IDLH = 50,000 ppm • LEL = none

24. Carbon Monoxide (CO) • Colorless, odorless gas • Slightly lighter than air • Chemical asphyxiant • Primary source: incomplete decomposition of organic material • Gasoline-fueled combustion engine • Unvented heaters

25. Carbon Monoxide (CO) • PEL = 50 ppm - TWA • TLV = 25 ppm - TWA • IDLH = 1500 ppm • LEL = 12.5%; UEL = 74.2%

26. Cleaning Up a Mess…

27. Confined Space Entry

28. Confined Space Management Procedures • Prevent unauthorized entry • Identify and evaluate the hazards prior to entry • Develop safe entry procedures • Acceptable entry conditions • Purging or ventilating • Barriers to protect from external hazards

29. Confined Space Entry Procedures • Test atmosphere before and during work • Provide at least one Attendant outside for the duration of entry operations • Rescue and Emergency Response procedures established

30. Confined SpaceEquipment • Atmosphere Testing and Monitoring Equipment • Ventilating Equipment • Communications Equipment • Personal Protective Equipment • Body Harness and Lanyard (Safety rope)

31. Authorized Entrant Duties • Knows hazards, symptoms, and consequences • Proper use of equipment • Communicate with attendant • Exit promptly when necessary

32. Attendant Duties • Trained in CPR and basic First Aid • Remains outside of the Confined Space • Communicates with Entrants • Monitors Entrant & surrounding activity

33. Attendant Duties • Summons rescue if needed • Keeps unauthorized persons away • Performs non-entry rescues • Performs only attendant duties

34. Pit Entry Equipment Lanyard Full Body Harness

35. Tripod with Winch One attendant can usually operate

36. Is “Reach” an issue with lanyard?

37. Air Supplied Respirator • Compressed air tank on back of user or • Mask hose connected to a large compressed air tank or • Mask hose connected to an electric air pump located in fresh air • Must fit test respirator for users

38. Personal Toxic Atmosphere Monitor • Provides emergency warning to user if toxic atmosphere develops suddenly • Should be able to detect hydrogen sulfide & oxygen levels

39. Entry Procedures • Air supplied respirator must be worn unless: • Continuous forced air is sufficient to maintain the space as safe and,

40. Entry Procedures • Atmosphere is tested prior to entry & continuously during entry by outside attendant and/or with a personal monitor on the entrant • Atmospheric Testing for: • Oxygen • Flammability • Toxic Contaminants

41. Minimum Requirements for Farm Pit Entry • A portable, electronic gas monitor for hydrogen sulfide, methane & other combustible gases, plus oxygen

42. Minimum Requirements for Farm Pit Entry • An electrically-powered (AC) ventilation blower, 900 to 1200 cfm, designed for ventilating confined spaces

43. Minimum Requirements for Farm Pit Entry • A rescue harness, tripod, cable and hand-operated winch system capable of raising and lowering an entrant in an emergency.

44. Equipment Costs to Maintain Pit Entry Safety Equipment About $700 ann. cost, median set, 10 yr life, 6% int. J. M. Shutske, M. A. Purschwitz, L. D. Jacobson, K. A. Janni, 1995. Costs and Issues Associated With Implementing Industrial Confined Space Standards in Manure Storage Facilities, J. Ag. Safety & Health, 1(2):83-91.

45. Research on “Smart ventilation” strategies

46. Zhao et al., 2005. Ventilating Confined Manure Storages: Progress Report, ASABE Paper No. 055019.

47. Summary: Pit Entry • Test atmosphere and provide continuous ventilation • Entrant should be provided with proper PPE & trained on its use • Attendant should be prepared for emergencies & able to quickly extricate entrant • Train workers on safe entry procedures initially, at time of entry & annually – Document training

48. Outdoor Storages • Fencing • Embankments and tractor overturns

49. Summary: Manure Storage Safety

50. References • ASAE EP470 JAN1992 (R2005) Manure Storage Safety • National Ag Safety Database http://www.cdc.gov/nasd/