WELLINGTON COUNTY FIRE TRAINING 2013-56LESSON PLAN
OFM curriculum –Component -
Section - / Lesson Plan – Silo Gas Awareness
Prepared by- T.O Karn
Preparation date – Sept 2013
SPECIAL PRECAUTIONS
LEARNING OUTCOME(S):The learner will be able to:
- Discuss gases formed in silos
- Discuss characterisctics and hazards of carbon dioxide and nitrogen dioxide (silo gases)
- Identify common types of silos
- Discuss safety hazards and procedures when dealing with silo emergencies
INTRODUCTION: / ESTIMATED TIME:
APPLICABLE SECTION 21 GUIDANCE NOTES & SAFETY NOTE
Remember as the T/F you are a supervisor for this work period and will observe and enforce all appropriate health and safety measures for you lesson participants.
GN # 6 – 31 Agricultural Silos
Add any applicable SOG’s
PRESENTATION / ESTIMATED TIME:
LESSON OUTLINE / TEACHING AIDS
What is Silo Gas?
Silo gas is a confined space hazard that is formed after chopped sileage is loaded into the silo.
Natural fermentation takes place, releasing gases including carbon dioxide (CO2) and nitrogen dioxide (NO2).
Carbon Dioxide – facts and characteristics
- This gas is produced in great amounts
- CO2 replaces oxygen inside the silo
- Odourless and colourless
- CO2 is heavier than air and will settle in low-lying areas
- High concentrations give little warning to persons that they are about to be overcome by a lack of oxygen
- Highly toxic gas
- Strong bleach like odour
- Low-lying yellow, red or dark brown fumes. Gas will only be seen in extremely high concentrations. Lower concentrations will be colourless but remain extremely harmful
- Heavier than air and may collect in silo chutes, feed rooms,adjoining barns and at the base of the silo
- Generally reach peak levels about 3 days after silo is filled
- NO2 will cause severe irritation to nose and throat and may lead to inflammation of the lungs, short of breathe, headaches and nausea
- Symptoms may present themselves similar to phnemonia 2 to 6 weeks after intial exposure
****show youtube video – 1. ‘silo gas concerns”
2. “deadly silo gas video”
COMMON TYPES OF SILOS
Conventional silo
- Made of banded concrete slabs, poured concrete, or steel plates
- Top unloading
- Fires can result from malfunctioninf unloading equip, spontaneous combustion, crops put in to dry or barn fires in close proximity
- Rescue may be required for farmers who enter the silo to service unloading equipment
- Made of poured concrete or steel plates
- Silos unloaded from the bottom
- Fires usually occur from O2 getting into the silo from leaking seams, from unloading areas, crops put in too dry, barn fires in close proximity
- Farmers generally do not have to enter this silo during the unloading phase
- Extremely O2 deficient atmosphere
- An oxygen limiting silo that has been converted to a conventional silo
- May be unloaded from the top and / or the bottom
- Hazards from both silo styles may be present
Fires
- Toxic gases may be produced when a silo is burning
- grain dust and possible presence of methane gas can produce an explosive atmosphere
- Never enter a structure until all hazards have been removed and / identified
- Ensure adequate water supply before commencing suppression poerations
- Consider the use of foam
- In Conventional silos only apply as much water / foam as necessary to ensure containment. Large amounts of water may cause collapse
- Until the structure has been emptied it should not be considered extinguished
- Do not climb the outside ladder or chute as heat may have damaged the ladder system or structure
- In an oxygen limiting silo never open hatches, doors or spray water into the structure. Introducing water and oxygen may result in an explosion
- Consult specific manufacturer of silo for safe procedures for fire suppression
- “Grain silo explosion demo”
- “live dust explosion at FM global research centre”
- Identify silo and associated risks and hazards
- Air monitoring must be used to determine O2 levels
- Mechanical ventilation may be necessary
- Lock out / tag out any loading or un-loading equip as well as any additional p[ower sources assoc with the silo
- Use of full scba will be required when entering the silo
- Treat the silo as a confined space and follow confined space protocols
- Full ppe including harness and sfatey lines should be worn by the rescuer
- Ensure all power is locked out and tagged out
- If worker is submerged or cannot be pulled out cut “V” or “U’ shaped holes in opposite sides or more equally spaced around the bin to release the grain
- DO NOT open the hopper or hole beneath the victim
- Use retaining walls or “coffer dam’ if the grain is above the victims head
- Use shovels and vacuums to remove the grain from around the victim
- Provide breathing assistance (O2) if necessary
- Provide emotional support to the victim
- DON’T GIVE UP……persons have survived up to 2 hours after submersion in the grain
1. stored products research and educational centre: grain bin rescue”
2. “grain bin safety 2011” / Ensure personell are confident in the operation of gas monitoring equipment carried on apparatus.
SUMMARY: / TEACHING AIDS
Responding to incidents involving silos, grain bins and other farm equipment can be extremely hazardous and dangerous to first responders. Hazards must be identified before undertaking any fire suppression activities or rescues of trapped workers. Fully understanding hazards and working within established SOG’s and policies will ensure safe workijg conditions for all emergency personell.
REFERENCE MATERIALS: / TRAINING AIDS REQUIRED:
OHSA - grain entrapments
Silo Gas Safety – Alberts agriculture
Farm Safety Assoc. – silo gas dangers
National safety Council – Silo Gas Hazards / Gas monitor for demo
PPT presentation silo hazard awaerness
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