For more: http://www.extension.org/67660 Gypsum products created from construction industry waste streams provide low-input cost bedding. Some dairies report decreased somatic cell counts in milk with its use. Recently, several incidents involving human and livestock death or injury have highlighted the possible creation of dangerous gases at farms using gypsum bedding. Human lives were lost at two separate events. In a third incident, a 2-year old and 4-year old were found unconscious adjacent to a manure storage where gypsum was present. In the European Union (EU) several agencies have forbade the use of gypsum as bedding based on losses of livestock as well as previous policies that restricted gypsum from landfill disposal. Gypsum is a common term for hydrated calcium sulfate (CaSO4¬-2H2O). It is suspected that under the right manure storage conditions anaerobic bacteria convert the sulfur (S) in gypsum to hydrogen sulfide (H2S), a gas that can be deadly. Movement such as agitation of manure can lead to large H2S fluxes and localized dangerous levels of the gas. While this is concerning, there remain many farms that utilize gypsum without incident. Data on this subject are lacking. The goal of this symposium presentation is to update attendees on this ‘current event’ in manure management.

1. LPELC Waste to Worth Conference
Denver, CO
April 4, 2013
Robb Meinen
Penn State Dept. of Animal Science
(814) 865-5986
rjm134@psu.edu
Gypsum Bedding
Risks and Recommendations for Manure Handling

2. What is gypsum bedding?
• By-product of drywall/construction industry
• Low-cost bedding input
• Some report increased health & mild quality
• Contains Sulfate Dihydrate
• CaSO4-2H2O
• Northeast regional use
• Unsure of national use

3. Farm #1 – Unconscious Children (Sept 2012)

4. Agitation Equipment Location

5. Manure
Storage
• Note elevation difference between this side of storage and
agitation equipment seen on far side.
• Photo 3 days after incident.
• Manure removal has decreased depth here.

6. • 2-year old & 4-year old
each unconscious
• “Blue” in appearance
• Over 30 minutes to
revive one boy
• Road rash on knees
• H2S highly suspected
(>500 ppm)
• Gypsum/sawdust bedding

7. Agitation
Tricycle

8. The good news…

9. Farm #2 - Child death (2011)
2-year old found here
• Gutter collection under floor
leads to storage
• Father agitating
• Gypsum bedding used

10. Farm #3 – 3 deaths (May 2012)
• Father, 18 year old, 14 year old
• Truck & tractor still running
• Bodies recovered from storage
• Farm beds with gypsum only
• Later worker reports temporary
blindness after agitation

12. Farm #4 - Dog dies, Man Hospitalized (Aug 2012)
• Kelowna, BC
• Solid manure at cattle feedlot
• Man trying to perform CPR on dog
• At least he called his brother before getting off tractor
• A reminder that manures do not need to be liquid or contain
gypsum to be deadly

13. Additional scenario for caution:
the breaking of storage crust

14. 2 very early studies
We hope to build on these pre-trials

15. PSU Study
• Benchtop
• Small volumes
• Dairy manure
• Treatments:
1. No gypsum
2. Low amount gypsum
3. High amount gypsum
• Gypsum increased H2S emission
• Large spikes occur during agitation vs. static
– (Purple compared to adjacent Green bar, and Orange
compared to adjacent Light Blue bar)
ppmH2S 1 8
1 8 24 51 79 103 163 242
Hours after Preparation
Eileen Wheeler, Mike Hile, teal.

16. Wisconsin Study
• Benchtop
• Small volumes
• Dairy manure from anaerobic system
• Treatments:
1. No gypsum
2. Gypsum
• Gypsum increased H2S emission
• H2S increases sharply after gypsum addition and
then levels off
• No agitation
Rebecca Larson and Asli Ozkaynak

17. Confined Spaces
– Do not enter them!!
– Gases can cause loss of
consciousness and death.
– Always assume there are gases
present.

18. Gases
• Some are odorless
• Most are colorless
• Some are explosive
• Some sink
• Some rise
• If it ‘aint Oxygen –
you ‘aint breathing!

19. If someone is overcome by gas
1. Ventilate – turn on fans
- open doors, curtains, covers
2. Call 911 – mention confined space
3. Cease agitation or manure movement
• Do not go in after an unconscious person!
– 22% of Ag confined space deaths occur to rescuers.
(Field & Beaver, 2009, Purdue University)
• Always carry a mobile phone or radio when working
around manure.

20. Managing Confined Space Entry
• Identify potential confined spaces
• Understand potential hazards of each
– Oxygen deficiency
– Combustible gases (methane)
– Toxic gases (hydrogen sulfide, nitrogen dioxide,
carbon monoxide, carbon dioxide, ammonia)
• Measure, ventilate, buddy up

21. Some gypsum policies of note
• Some policies in the European Union have
prohibited gypsum use for bedding
• Some EU and US landfills will not accept
gypsum due to gas concerns

22. Conclusions & Questions
• Open-air storages need respect
• Gypsum highly suspected as trigger to H2S
production
• More work & information is needed
– Consider adding these measurements or
variables to your research and field work
• Please pass these concerns to your producer
clientele