Oct. Web Exclusive! OSHA Standards: Guarding Field & Farmstead Equipment

10/9/2012

OSHA Standards
for Growers


Guarding Field and
Farmstead Equipment


by Chris E. Marsh, M.Ed.


        The purpose of OSHA's guarding regulation is to provide for the protection of employees from hazards associated with moving machinery parts of farm field equipment and farmstead equipment. (Cotton gins are also covered in the section, but not in this article.) First, general requirements are covered which apply to all farm equipment, and then field equipment and farmstead equipment will be covered separately.

General requirements


Definitions
        Farm field equipment means tractors or implements, including self-propelled implements, or any combination used in agricultural operations. Farmstead equipment means ag equipment normally used in a stationary manner. This includes, but is not limited to, materials handling equipment and accessories for such equipment whether or not the equipment is an integral part of a building. Ground-driven components are components that are powered by the turning motion of a wheel as the equipment travels over the ground. A guard or shield is a barrier designed to protect against employee contact with a hazard created by a moving machinery part.

Power takeoff shafts
        Power takeoff shafts are the shafts and knuckles between the tractor or other power source and the first gear set, pulley, sprocket or other components on power takeoff shaft-driven equipment. At the time of initial assignment and at least annually thereafter (be sure and document this), the employer shall instruct every employee in the safe operation and servicing of all covered equipment with which he is or will be involved, including at least the following safe operating practices.

a. Keep all guards in place when the machine is in operation

b. Permit no riders on farm field equipment other than persons required for instruction or assistance in machine operations

c. Stop engine, disconnect the power source and wait for all machine movement to stop before servicing, adjusting, cleaning or unclogging the equipment, except where the machine must be running to be properly serviced or maintained, in which case the employer shall instruct employees as to all steps and procedures that are necessary to safely service or maintain the equipment.

d. Make sure everyone is clear of machinery before starting the engine, engaging power or operating the machine.

e. Lock out electrical power before performing maintenance or service on farmstead equipment.


Methods of guarding
        Except as otherwise provided in this subpart of the OSHA standard, each employer shall protect employees from coming into contact with hazards created by moving machinery parts as follows: (a) through the installation and use of a guard or shield or guarding by location or (b) whenever a guard or shield or guarding by location is infeasible, by using a guardrail or fence.

Strength and design of guards
        Where guards are used to provide the protection required by the above OSHA standard, they shall be designed and located to protect against inadvertent contact with the hazard being guarded. Unless otherwise specified, each guard and its supports shall be capable of withstanding the force that a 250-pound individual leaning on or falling against the guard would exert upon that guard. Guards shall be free from burrs, sharp edges and sharp corners, and shall be securely fastened to the equipment or building.

Guarding by location and railings
        A component is guarded by location during operation, maintenance or servicing when, because of its location, no employee can inadvertently come in contact with the hazard during such operation, maintenance or servicing. Where the employer can show that any exposure to hazards results from employee conduct that constitutes an isolated and unforeseeable event, the component shall also be considered guarded by location.

        Guardrails or fences shall be capable of protecting against employees inadvertently entering the hazardous area.

Servicing and maintenance
        Whenever a moving machinery part presents a hazard during servicing or maintenance, the engine shall be stopped, the power source disconnected, and all machine movement stopped before servicing or maintenance is performed, except where the employer can establish that:

a. The equipment must be running to be properly serviced or maintained.

b. The equipment cannot be serviced or maintained while a guard or guards otherwise required by this standard are in place.

c. The servicing or maintenance can be safely performed.


Farm field equipment

Power takeoff guarding
        All power takeoff shafts, including rear, mid or side-mounted shafts, shall be guarded either by a master shield, as provided in the next paragraph, or by other protective guarding.

        All tractors shall be equipped with an agricultural tractor master shield except where removal of the tractor master shield is permitted by the next paragraph. The master shield shall have sufficient strength to prevent permanent deformation of the shield when a 250-pound operator mounts or dismounts the tractor using the shield as a step.

        Power takeoff-driven equipment shall be guarded to protect against employee contact with positively driven rotating members of the power drive system. Where power takeoff-driven equipment is of a design requiring removal of the tractor master shield, the equipment shall also include protection from that portion of the tractor power takeoff shaft that protrudes from the tractor.

        Signs shall be placed at prominent locations on tractors and power takeoff-driven equipment specifying that power drive system safety shields must be kept in place.

Other power transmission components
        The mesh or nip points of all power-driven gears, belts, chains, sheaves, pulleys, sprockets, and idlers shall be guarded. All revolving shafts, including projections such as bolts, keys or set screws, shall be guarded, except smooth shaft ends protruding less than one-half the outside diameter of the shaft and its locking means. Ground-driven components shall be guarded in accordance with the first two paragraphs of this section if any employee may be exposed to them while the drives are in motion.

Functional components
        Functional components, such as snapping or husking rolls, straw spreaders and choppers, cutter bars, flail rotors, rotary beaters, mixing augers, feed rolls, conveying augers, rotary tillers, and similar units, which must be exposed for proper function, shall be guarded to the fullest extent that will not substantially interfere with normal functions of the component.

Access to moving parts
        Guards, shields and access doors shall be in place when the equipment is in operation. Where removal of a guard or access door will expose an employee to any component that continues to rotate after the power is disengaged, the employer shall provide the following in the immediate area.

a. A readily visible or audible warning of rotation; and

b. A safety sign warning the employee to look and listen for evidence of rotation and not remove the guard or access door until all components have stopped.


Farmstead equipment

Power takeoff guarding
        All power takeoff shafts, including rear, mid or side-mounted shafts shall be guarded either by a master shield, as provided in the following paragraph, or other protective guarding. Power takeoff-driven equipment shall be guarded to protect against employee contact with positively driven rotating members of the power drive system. Where power takeoff-driven equipment is of a design requiring removal of the tractor master shield, the equipment shall also include protection from that portion of the tractor power takeoff shaft that protrudes from the tractor. Signs shall be placed at prominent locations on power takeoff-driven equipment specifying that power drive system safety shields must be kept in place.

        The mesh or nip points of all power-driven gears, belts, chains, sheaves, pulleys, sprockets and idlers shall be guarded. All revolving shafts, including projections such as bolts, keys or set screws, shall be guarded, with the exception of:

a. Smooth shafts and shaft ends (without any projecting bolts, keys or set screws), revolving at less than 10 RPM, on feed-handling equipment used on the top surface of materials in bulk storage facilities, and

b. Smooth shaft ends protruding less than one-half the outside diameter of the shaft and its locking means.


Functional components
        Functional components such as choppers, rotary beaters, mixing augurs, feed rolls, conveying augers, grain spreaders, stirring augers, sweep augers and feed augers, which must be exposed for proper function, shall be guarded to the fullest extent that will not substantially interfere with the normal functioning of the component.

        Sweep arm material gathering mechanisms used on the top surface of materials within silo structures shall be guarded. The lower or leading edge of the guard shall be located no more than 12 inches above the material surface and no less than 6 inches in front of the leading edge of the rotating member of the gathering mechanism.

        Exposed auger flighting on portable grain augers shall be guarded with either grating-type guards or solid baffle-style covers as follows:

a. The largest dimensions or openings in grating-type guards through which materials are required to flow shall be 4.75 inches. The area of each opening shall be no larger than 10 square inches. The opening shall be located no closer to the rotating flighting than 2.5 inches.

b. Slotted openings in solid baffle style covers shall be no wider than 1.5 inches or closer than 3.5 inches to the exposed flighting.


        Guards, shields and access doors shall be in place when the equipment is in operation. Where removal of a guard or access door will expose an employee to any component that continues to rotate after the power is disengaged, the employer shall provide the following in the immediate area.

a. A readily visible or audible warning of rotation; and

b. A safety sign warning the employees to:

1. Look and listen for evidence of rotation; and

2. Not remove the guard or access door until all components have stopped.


Electrical disconnect means
        Application of electrical power from a location not under the immediate and exclusive control of the employee(s) maintaining or servicing equipment shall be prevented by providing an exclusive, positive locking means on the main switch that can be operated only by the employee(s) performing the maintenance or servicing. In the case of material-handling equipment located in a bulk storage structure, by physically locating on the equipment an electrical or mechanical means to disconnect the power.

        All circuit protection devices, including those that are an integral part of a motor, shall be of the manual reset type except where the employer can establish that because of the nature of the operation, distances involved and the amount of time normally spent by employees in the area of the affected equipment, use of the manual reset device would be infeasible. If there is an electrical disconnect switch available to the employee within 15 feet of the equipment upon which maintenance or service is being performed, a sign must be prominently posted near each hazardous component that warns the employee that unless the electrical disconnect switch is utilized the motor could automatically reset while the employee is working on the hazardous component.





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