Dangers in the Air on Farms:

Transcription

1 Dangers in the Air on Farms: Manure Gas, Silo Gas John Shutske, Extension Agricultural Health and Safety Specialist & Professor

2 This segment of the program From the UW Center for Agricultural Safety & Health Thank you to the state of Wisconsin for your generous support of these efforts

3 First Unusual Case to be discussed Our hearts go out to the Biadasz family Bob, Diane, Mike s sisters Lisa, Amy & Megan Thank you for your passion, your commitment & assistance Mike s incident, a fatal H 2 S exposure happened on August 15, 2016

4 Details reported August 18, 2017, CDC s Morbidity & Mortality Weekly Report (MMWR)

5 Why Was this Unusual & Warranting Attention?

6 When Farm Workplace Deaths Happen Multiple Factors

7 Some of These Known in this Case Weather cool morning, no wind, 80 s week before, thermal inversion Significant sulfur being fed & showing up in manure tests Sulfur also an issue in PA with gypsum cow bedding Crusted surface, agitation, rapid gas release Awareness of dangers (plus working alone & other factors)

8 Some Fundamentals: Manure Storage

9 Anaerobic microorganisms in manure degrade organic matter During breakdown, manure gases are produced & released in storage, including: Methane (CH 4 ) Carbon Dioxide (CO 2 ) Ammonia (NH 3 ) Hydrogen Sulfide (H 2 S) Gases are dispersed into atmosphere when liquid is disturbed Gas Production

10 Hydrogen Sulfide (ATSDR 2006) Property Concentration in air (ppm) Typical background level Odor threshold (AIHA 1989) Offensive odor, headache 0.3 Very offensive odor 3-5 Asthmatics affected 2 Human gas 3-18 Olfactory paralysis 150 Central nervous system depression, loss of consciousness, neurological problems may persist >500 Lung paralysis, collapse, death >600-1,000 (concentrations in actual events are uncertain) **Agency for Toxic Substances and Disease Registry

11 Purdue Study 139 cases involving manure storage nationwide over last several decades Multiple victim situation NOT uncommon We a five-person incident in MI in Attributed to methane H 2 S likely played a role as well

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14 Common Denominators from My Study of These Events over 32 Years Often complete lack of awareness 1 Have not seen a case where air was being monitored; SCBA was being used; or/and where there were special efforts to maximize & add ventilation Multiple deaths event are not uncommon Those first on the scene often struggle to respond Events I ve looked at most closely followed a HOT period of days

15 So What Does Mike s Case Tell Us About Prevention?

16 New Bulletin Search Google UWEX Learning Store Reducing Risks from Manure Storage Gases Authors: Larson, Aguirre-Villegas, Shutske, Skjolaas, Nelson, Shauer and Erb

17 Safety Hierarchy Applied to Agriculture (Safety Engineering Pyramid) Eliminate the Hazard Get rid of the hazard completely, replace old systems, change production and other system factors In this case, includes excess sulfur Safeguards, Separation, Etc. Includes failsafe sensors & monitors. Can include fencing, barriers. With equipment this includes guards, shields, ROPS Warnings, Instructions Warning labels, owners manuals, training guides, written protocols. (I argue that these should be lower on hierarchy) Train & Educate Provide how to instruction, demonstrate safe processes and procedures, and encourage the trainee to demo back. Use Personal Protective Equipment Includes masks, respirators, SCBA, safety glasses, hearing protection, etc.

18 Manage sulfur Monitoring has its place, but, must: Know that presence of wind (air movement) is critical to evacuate contaminant Temperature plays a role more study needed Crust impedes gas release More agitation & movement means more rapid release

19 We Now Know If pumping and work near liquid manure in ZERO or low wind, there is significant hazard potential By pumping in a high hazard potential and relying on lower safety hierarchy methods, risk increases In addition, we are concerned by the addition of ANY feed, bedding, or other high sulfur sources.

20 Let s Apply the Hierarchy to Confined Spaces Worker can enter and perform work Limited means of entry or exit Not designated for continuous occupancy

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22 Not just a tower silo issue Bags Bunkers Piles

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24 For Confined Spaces We Typically Recommend NOT going in wherever and whenever possible For farmers -- hiring work done by qualified, equipped professionals (in insurance, we called this risk transfer) Maximum ventilation Continuous air monitoring Working in team setting, equipping entrant w/life harness & outside means to retrieve victim Self-contained breathing apparatus

25 Inside OR Outside, a Few Notes on Respirators Typical masks, cartridges, air purifying respirators provide zero protection from dangerous H 2 S or NO 2 levels Many use considerations regulatory and other: fit testing, medical oversight, facial hair, and others

26 SCBA Provides Air & Eye Protection Cost ($1,500 minimum) Lots of training, maintenance, and skill needed THE ONLY option with dangerous gas levels or lack of oxygen

27 On Monitors They are really only a NO HAZARD verification tool (based on John Shutske s opinion) They are not a tool designed to help you skate on the thin edge of the ice They are not a perfect technology (far from it) We must WATCH for dependency that is, luring people to false sense of security

28 Cost - initial purchase and ongoing calibration Training required Gases and conditions monitored Sensor flexibility and interchangeability Ability to store/log data Battery life and/or replaceability Monitor Considerations

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30 Some Considerations * -Gas Monitors: Generally: O 2, Combustible gases, Hydrogen Sulfide, Carbon Monoxide In the $ $2,500 range (or higher) Single gas monitors: Can select H2S only monitor for around $150 (will not give you indicators of low O 2 or other gases)

31 Pumps that aid air movement into device Calibration kits Bump testing kits Ongoing service (and calibration off site) Additional Considerations

32 Minimal (ONLY OUTSIDE) Single gas, inexpensive Often short life (typically one or two years) Data logging limits Few adjustments Simple Pretty robust and reliable

33 If Manure or Silage/Forage is a Commercial Service Business for Me I m going to invest in a higher end 4-gas monitor with the calibration gear (H2S, O2, Flammable/Explosive, NO2) An SCBA unit for emergency & occasional confined space use in the scope of a bigger confined space entry program Appropriate ventilation fans, tubing, retrieval equipment I would want to invest more in worker education and other hands-on training

34 We Must Be Careful that Safety Actions Don t Inadvertently Increase Risk A monitor that s used incorrectly Getting too far in to an unsafe situation (even with a monitor) Incorrect use of a respirator or airpack (SCBA) Asking an older worker (or those with heart/lung) issues to wear a mask

35 Summary -- Big Picture: Farming = high risk venture Getting rid of controllable hazards is best As we step down safety hierarchy, risk changes Avoid circumstances where hazard cannot be completely eliminated (outside agitate & pump only on windy days/times; enclosed spaces hire experts or invest in array of confined space gear, training, and required protocols) Monitor ONLY to verify no gas! Wear your seatbelt. Get rest when you can. Be safe The world needs you!

36 Thank You to the men and women who work to make our ag industry strong & feed a growing world population!