grain elevator · pdf file1 grain elevator safety brad freeman, cih, csp gary hulbert, chmm,...

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Grain Elevator SafetyBrad Freeman, CIH, CSP

Gary Hulbert, CHMM, CSP

Grain Elevator Overview

• Components of grain elevators

• OSHA standards

• Hazards associated with grain handling facilities:• Engulfment

• Explosions/combustible dust

• Electrical hazards

• Entanglements

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Grain Elevator

• Grain elevators typically consist of:

• Dump pit

• Leg

• Distributor

• Down spouts

• Bins

• Conveying system

Parts of a grain elevator

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Dumping grain into the dump pit

Grain Leg with Down Spouts

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Grain Leg-Bucket elevator

1964-2013 Statistics• Purdue’s Agriculture Confined Space

Incident Data Base

• 1201 documented incidents in Grain Storage Facilities

• 809 involved entrapment or engulfment with free flowing grain

• Entrapment represents 67% of all cases

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1964-2013 Statistics

• 47% of entrapments had corn as the medium

• 16% of entrapments were under the age of 21

• 1964-2008 – 73% of entrapment were fatal

• 2008-2012 – 46% entrapments were fatal

1964-2013 Statistics

• 300,000 exempt grain handling facilities

• 70% of incidents occur on exempt facilities

• Falls from heights are on the increase since the 1990s

• Equipment entanglements are third leading incident

• Grain dust explosions

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Agriculture Confined Space Injuries-2013

• Purdue annual summary of grain related entrapment and engulfments

• 33 grain entrapment cases, 14 falls, and 12 equipment entanglements (including augers)

• Entrapments account for 49% of documented cases

• 4 Asphyxiation/poisoning

OSHA Standard 1910.272

• OSHA issued grain handling standard in 1987

• Standard addresses walking on or underneath grain

• The hazards include: engulfment and entrapment

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OSHA Standard 1910.272

• Standard covers: • Hot work

• Entering bins

• Inside bucket elevator legs

• Preventative maintenance

• Housekeeping

• Emergencies and training

OSHA Standards

• 1910.22 Walking/working surfaces

• 1910.23 Guarding floor and wall openings

• 1910.111 Storage of anhydrous ammonia

• 1910.272 Grain handling facilities

• 1910.301-399 Electrical

• 1910.1000 Air contaminants

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Distribution of Entrapments

• 78% in the Midwest

• 12% in the South

• 6% in the West

• 4% in the Northeast

Geographic Distribution of Grain Entrapments for 2013

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Engulfment in grain bin from:Standing on moving grain

Bridging conditionsLoosening grain on side of bins

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Worker Entry into Grain Storage Bins –Flowing Grain Buries Worker

2-3 seconds to react with auger running

4-5 seconds worker is trapped

22 seconds worker is covered

Worker Entry into Grain Storage Bins –Bridging Condition

Bridging from unloading – auger is off

Auger starts – grain falls

Worker completely covered

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Worker Entry into Grain Storage Bins –Accumulation on Side of Bin

Pile of grain on side Grain falls Worker suffocates

Worker Entry into Grain Storage Bins –Rescue During Bridging

Person outside secured to bin

Person on ground can go for help or assist in rescue

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Monday, March 23, 2015

Rescue Equipment Available

Grain rescue tube surrounds worker

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Case Study - Engulfment

• Facility manager and worker enter bin when grain stops flowing

• Auger is left on

• After 5 minutes, manager exits bin leaving worker alone

• Worker becomes completely engulfed

• No one is aware that worker is still in bin

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Cutting into a grain bin


Hazard Prevention

When workers enter storage bins:• Turn off and lock out all powered

equipment

• Prohibit walking down grain

• Provide all employees a body harness with a lifeline or a boatswains chair

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Hazard Prevention

• Provide an observer stationed outside the bin or issue entry permit

• Test the air within a bin or silo prior to entry

• If detected by testing, vent hazardous atmospheres

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Westwego Louisiana Grain Elevator

• 1977 explosion

• 36 fatalities

• 7 fatalities were Federal Grain Inspection Services (USDA) employees

• Triggered regulations


Westwego Louisiana Grain Elevator

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Galveston Texas Grain Explosion


Galveston Grain Explosion

• December 1977

• 6 Federal Grain Inspection Services (USDA) fatalities

• 18 fatalities

• Hearings were held in 1978 before the Subcommittee on Compensation, Health and Safety pertaining to OSHA Oversight on Grain Dust Explosions


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Atchison Kansas-6 employees killed 2011

Combustible Dust - Hazard Prevention

• Written housekeeping program

• Identify "priority" housekeeping areas within 35 feet of inside bucket elevators

• Dust accumulations in these priority housekeeping areas shall not exceed 1/8th inch

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Combustible Dust

To prevent dust explosions:• Implement a PM program

• Minimize ignition sources through controlling hot work

• Install wiring and electrical equipment suitable for hazardous locations

• Design and properly locate dust collection systems to minimize explosion hazards

• Install an effective means of removing ferrous material from grain streams

Combustible Dust Dust

• Bearings must be mounted externally to the leg casing or the employer must provide vibration, temperature, or other monitoring

• Bucket elevators must be equipped with a motion detection device which will shut-down the elevator when the belt speed is reduced by no more than 20% of the normal operating speed

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Case Study – Combustible Dust Explosion

• Tail pulley may have come off shaft

• Pulley struck concrete wall, creating sparks

• Mineral oil used to wet grain was not in use on day of explosion

• No alignment monitor for belt

Insert photo

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Grain Explosion

Grain Explosion

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Grain Explosion

Electrical

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Insert photo

Floor Opening

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Machine Guarding

• Screw conveyors

• Sweep augers

• Rotating parts of motors

• Belts and pulleys

Screw Conveyor

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Case Study – Caught in Auger

• Top of auger approximately 3 feet above ground

• Cover had been removed from top of auger

• Worker attempted to step over auger

• Leg wrapped up in auger

• EMS can’t remove worker

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Sweep Auger

• A horizontal auger used to push grain remaining at the bottom of a storage bin

• Sweeps grain toward the bin's discharge sump opening

• The sweep rotates around the discharge opening to "sweep" the grain toward that opening

• The screw portion of an auger is often at least partially covered by some type of guard

Sweep Auger

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Sweep Auger

Sweep Auger Policy

• 2009 OSHA issued letter of interpretation

• Employees could not work inside bin with energized auger unless completely guarded

• 2013 OSHA issued 10 criteria policy

• Based on a settlement agreement between OSHA and National Grain and Feed Association (NFGA)


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Sweep Auger Policy

• Follow 1910.272 permit requirements

• De-energized & LO/TO sweep and sub-floor augers before setting-up/digging-out

• Install and secure grates over sub-floor auger

• Sweep auger must be guarded as designed by manufacturer

• No walking on grain at depths presenting an engulfment hazard

• Rescue trained

Sweep Auger Policy

• Use engineering controls to prevent contact with auger (use of administrative controls alone is insufficient)

• Use speed control mechanism or bin stop device to prevent uncontrolled rotation of the sweep auger

• No hands, legs, or other similar means to manipulate an operating auger

• To adjust auger, it must be unplugged (w/plug controlled by adjuster) or locked out

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Grain Vacuum

Grain Vacuum

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Grain Vacuum Hazards

• Used on partially spoiled grain

• Vacuum operators are at risk of being engulfed due to bridging and grain collapse

• Grain vacuums should have emergency stopping device

• Operators need to follow manufacturer operating guidelines

Grain Vacuum Hazards

• Dropping or releasing the nozzle on the grain surface can quickly pull the nozzle down into the grain and become buried

• In response, the operator may try to locate and lift the nozzle while the vacuum is running causing the grain to be sucked out from under them, burying him or her in seconds resulting in a fatality

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Conclusion

• Grain elevator overview

• Statistics

• Standards that apply to commercial operations

• Hazard prevention

• Combustible dust

• Machine guarding

• Resources

Questions?

Gary Hulbert, CHMM, CSP

[email protected]

Phone number: 574-583-9216

Brad Freeman, CIH, CSP

[email protected]

812-876-4904

grain elevator · pdf file1 grain elevator safety brad freeman, cih, csp gary hulbert, chmm,...

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