Grain Elevator Safety Brad Freeman, CIH, CSP Gary Hulbert, CHMM, CSP Grain Elevator Overview Types and components of grain elevators OSHA standards Hazards associated with grain handling facilities: Engulfment Explosions/combustible dust Electrical hazards Entanglements 1
Grain Elevator Grain elevators typically consist of: Dump pit Leg Distributor Down spouts Bins Conveying system Parts of a grain elevator 2
Dumping grain into the dump pit Grain Leg with Down Spouts 3
Grain Leg -Bucket elevator 1964-2013 Statistics Purdue s Agriculture Confined Space Incident Data Base Entrapment represents 80% of all cases 45% of entrapments had corn as the medium 20% are under the age of 21 4
1964-2013 Statistics 1,640 documented grain bin incidents 1,201 involved entrapment or engulfment with free flowing grain 1964-2008 73% of entrapment leads to death 2008-2012 46.2% entrapments lead to death 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 5
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 6
OSHA standards OSHA Standards 1910.22 Walking/working surfaces 1910.23 Guarding floor and wall openings and holes 1910.111 Storage of anhydrous ammonia 1910.272 Grain handling facilities 1910.301-399 Electrical 1910.1000 Air contaminants OSHA Standard 1910.272 Standard covers: Hot work Entering bins Inside bucket elevator legs Preventative maintenance Housekeeping Emergencies and training 7
Grain Handling Engulfment More than 600 people have been engulfed and suffocated over past 40 years Purdue research indicates that 80% of cases resulted in fatalities Geographic Distribution of Grain Entrapments for 2013 8
Engulfment in grain bin from: Standing on moving grain Bridging conditions Loosening grain on side of bins 9
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 10
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 11
Pressure at each stage of engulfment Amount of time it takes to be engulfed in grain Rescue Equipment Available Grain rescue tube surrounds worker 12
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 13
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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 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 15
Combustible Dust - Hazard Prevention Written housekeeping program Identify "priority" housekeeping areas in within 35 feet of inside bucket elevators Dust accumulations in these priority housekeeping areas shall not exceed 1/8th inch Grain Dust Explosions 16
Westwego Louisiana Grain Elevator 17
Atchison Kansas-6 employees killed 2011 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 18
Combustible Dust OSHA's grain handling standard requires that belts for bucket elevators purchased after March 30, 1988 are conductive and have a surface electrical resistance not exceeding 300 megohms Bucket elevators must have an opening to the head pulley section and boot section to allow for inspection, maintenance, and cleaning Combustible Dust Bearings must be mounted externally to the leg casing or the employer must provide vibration, temperature, or other monitoring of the conditions of the bearings if the bearings are mounted inside or partially inside the leg casing 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 19
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 20
Grain Explosion Grain Explosion 21
Grain Explosion Electrical 22
Insert photo Floor Opening 23
Screw conveyors Machine Guarding Sweep augers Rotating parts of motors Belts and pulleys Screw Conveyor 24
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 25
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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 It is accurate to describe a sweep auger as an "unguarded... Auger Sweep Auger 27
Sweep Auger 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 28
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 Grain Vacuum 29
Grain Vacuum 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 30
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 Conclusion Grain Bin Overview Statistics Standards that apply to commercial operations Hazard prevention Combustible dust Machine guarding Resources 31
Questions? Gary Hulbert, CHMM, CSP ghulbert@dol.in.gov Phone number: 574-583-9216 Brad Freeman, CIH, CSP bfreeman@dol.in.gov 812-876-4904 32