Agricutural Health Promotion System

Agricultural Machinery and Your Health and Safety

Machines make farm operations faster and more efficient. Because of their speed and power, however, they can be dangerous to those who operate them or who happen to be nearby. This publication will help you understand the hazards associated with agricultural machinery and how to avoid them.

Machines are available to perform a wide range of farm tasks, including tilling, planting, applying chemicals, harvesting, and handling materials. Many agricultural injuries involve machinery. Figure 1, based on a recent national survey, shows the proportion of farm injuries resulting from various causes. Tractors and other agricul- tural machinery account for one-fourth of all injuries. Understanding how machinery functions and how to recognize hazards around machines are the key skills to using machines effectively and safely.

Management Strategies and Prevention Techniques

Prevention of injuries and illnesses is important to equipment manufacturers, dealers, farm managers, and farm workers. For any machine, the concern for safety must begin with the design phase and carry through to the use of the machine in the workplace. Manufacturers use a safety hierarchy in designing machinery to reduce the risk of injury (Table 1).

Top priority is given to eliminating safety hazards or risks from the machine itself. Manufacturers typically review the performance history of their machines and incorporate those changes that have a proven potential for reducing injury or illness. Changing the design to remove hazards from a machine makes the machine safer to operate. Of course, these design changes do not affect machines already in the field unless the manufacturer offers a recall or upgrade program. Owners or operators should inquire about these changes and see if their machines can be improved. Unfortunately, it is not always possible to retrofit older machines with the latest safety features.

Table 1. Safety Hierachy

Eliminating hazards is a noble goal for any designer and should be done whenever feasible. Unfortunately, it is often impossible to eliminate hazards completely. In many cases, dangerous parts of machines (for example, the headers of combines, baler pickup units, or mower blades) have to be somewhat exposed in order to perform their intended function. It may be possible to improve a design and reduce hazards, but most machines cannot be made foolproof.

Many modern machines include protective systems to enhance operator safety. These include guards and shields, rollover protection structures (ROPSs), interlocks, and controls. Safety technology of this type is quite effective in preventing injuries. However, it is not fail-safe. Guards are sometimes removed and not replaced, seat belts provided with ROPS-equipped tractors are often not worn, and interlocks or controls are sometimes bypassed by persons not concerned about safety. The bottom line is that even a safety device can fail, and there is no substitute for safe behavior.

Safety messages are otten placed on machinery by means of signs and decals. These safety signs point out some of the hazards present, what injuries or illnesses may be caused, and how to avoid the hazard. Safety signs, as illustrated in Figure 2, use a signal word and safety alert symbol to attract attention, a message panel to describe the hazard and its consequences, and often a pictorial panel that illustrates the hazard. Three signal words are used: CAUTION, WARNING, and DANGER, in order of increasing severity. The safety alert symbol, an exclamation point inside a triangle, means "pay attention—your safety is involved."

Another approach to enhancing safety is effective education about machine hazards and how to avoid potentially dangerous situations. Factory demonstrations, dealer training, and operator manuals are all parts of this program. Responsibility for effective safety education also rests with equipment owners and operators. As the owner of a machine, you should provide proper training in its operation. As an operator you should seek safety training. A key element in the training process is the operator's manual that is provided with the equipment. It contains important information on maintenance, operation, and safety. Also, be sure to read the safety decals on the machine.

Finally, there are several other ways to protect agricultural workers from injuries and illnesses. For example, each worker should have the basic personal protective equipment (PPE) needed for the job assigned. The PPE varies according to the job at hand but may include;

Safety glasses: to protect the eyes from flying particles;
Gloves: to protect against heat, cold, cuts, vibration, and chemicals;
Clothing: to protect against chemicals and environmental hazards;
Shoes: to protect against crushing, chemicals, and other hazards;
Hearing protection: to reduce dangerous noise levels;
Headgear: to protect the head and face from hazard exposure;
Respirator: to guard against respiratory chemical hazards.

You should also keep a first aid kit available on the farm and know how to practice first aid. Likewise, keep important phone numbers posted by the telephone and be sure workers know how to call for help.

Persons at Risk

Many agricultural machines require only a single operator. The operator controls the power and function of the machine from the designated station. Often the machine is operated with no one but the operator in the vicinity and the operator IS the only person at risk. Therefore, there may be no one nearby to help or summon help if an injury occurs.

In other cases, agricultural machines are used near other people for example, other equipment operators, bystanders, and children. These people have no control over the machine and may be unaware of its operation or hazards.

People operating equipment and people that are nearby need to be aware of the hazards around them and how to avoid these hazards. Machine operators need to be aware of the danger zones around the equipment and make sure other people do not get too close.

Hazard Recognition and Hazard Types

Machinery hazards can be categorized for easy identification. Table 2 lists the types of hazards commonly found on agricultural machines. Each of the hazard categories listed in Table 2 will be explained in the following sections. Some machine components may fall under more than one category. For example, a rotary mower blade has a sharp edge hazard because of its sharpened blade, an energy-release hazard due to its high speed, and a thrown-object hazard because it may pick up and throw a rock or other piece of debris while in use. These are called compound hazards.

Most machines present multiple hazards that is more than one hazard or hazardous component can be found on the machine. For example, a round baler has an entanglement hazard in the header area, a crushing hazard at the bale chamber door, and an energy-release hazard because of the hydraulic hoses or springs, to name just a few.

Hazard

Pinch points are found on machines where moving parts come together. Examples include gears, belts and sheaves, chains and sprockets, or rollers and wheels, as shown in Figures PP1, PP2, and PP3.

Possible Injuries

Fingers and toes can easily be pinched in these components, resulting In cuts, bruises, fractures, and even amputations.

Preventive Measures

Reduce exposure to pinch point hazards by keeping all guards and shields in place. Some components must be exposed in order to function. Know where these exposed components are and how to avoid the hazard as you work with the machine. Always turn off the power when you must service or adjust equipment! Take the key out if necessary to prevent someone from starting the machine while you are working on it.

Figure PP1 (right). Chain drive pinch point.

Figure PP2 (below right). Gear drive pinch point.

Figure PP3 (below). Feed roll pinch point.

ENTANGLEMENT

Hazard

Any exposed rotating component can catch your clothing, arm, or leg and wrap it around the component. Power take-off (PTO) shafts on equipment are common "wrappers" (Figure EN1). Components that roll or pull together, such as feed rolls, gathering chains, and headers or pickup units (Figures EN2 and EN3) are particularly dangerous.

Possible Injuries

Entanglement hazards often lead to broken bones, mangled limbs, crushed arms and legs, or amputated limbs. Entanglement in larger machines such as balers or combines may result in the entire body being crushed or mangled.

Preventive Measures

Never use equipment from which the guards or shields are missing. Do not attempt to clear an obstruction or unplug a header while the power is on. It takes only a fraction of a second to become entangled in a machine. It may take hours for rescue workers to remove you.

Figure EN1 (right). PTO entanglement.

Figure EN2 (below right). Cotton picker entanglement.

Figure EN3 (below). Corn header entanglement.

SHARP EDGES

Hazard

Sharp edges, also known as shear points, are common on many machines. Blades on mowers (Figure SE1), chippers, harvesters, saws, and tillage tools must be kept sharp for good performance. Sharp edges on machines that pass close enough together can cut or shear material between them. Augers running in tubes (Figure SE2), paddle conveyors, fan blades (Figure SE3), and some lift arms are also examples of sharp edges.

Possible Injuries

Mower blades, choppers, chain-saw blades, and other cutters typically move at high speed. They can slice through clothing and body parts with ease. Augers and other sharp edges can trap a hand or arm between a moving edge and a stationary edge, shearing through it with equal ease.

Preventive Measures

Take care around sharp surfaces and edges. Augers and conveyors should be protected with cages around them to prevent contact with the shear points. Keep these devices in p/ace! Mower blades are enclosed by the deck. However, not all blades can function properly if fully enclosed. Keep fingers and toes clear; do not walk backward or pull a mower toward you, especially on slopes where you may slip and fall. Other persons should stand clear when these machines are in operation.

Figure SE1 (right). Mower blade cutting hazard.

Figure SE2 (below right). Auger cutting hazard.

Figure SE3 (below left). Fan blade cutting hazard.

CRUSH POINTS

Hazard

Areas where components may close together, trapping a hand, arm, foot, leg, or the whole body, are crush points. The hitching of implements presents many opportunities for crushing injuries (Figure CP1). Likewise, any heavy load may present a crushing hazard if you reach or work under it (Figure CP2). Many crushing hazards exist where the parts of the machine come together during operation. For example, a person may be crushed by standing between the wheels of an articulated tractor when the tractor is steered into a turn. Someone could be crushed by standing in front of a tire as the machine moves forward (Figure CP3). Tractor-drawn implements may rise against the tractor frame or roll bar, trapping a person. Or a bale or other heavv object may fall from a loader bucket onto the operator.

Possible Injuries

Crushing hazards result in severe bruising and even fractures of the arms, legs, or upper body. The upper body can be crushed or squeezed, causing suffocation.

Preventive Measures

Keep all guards and shields in place. Stand clear of moving machines or components that can crush. Wait until the machine stops before you attempt a connection or adjustment. Pay attention to raised loads, making sure that they are supported properly.

Figure CP1 (below right). Crushing hazard for the foot.

Figure CP2 (below center). Large raised load crushing the whole body

Figure SE3 (below left). Tractor running over operator.

VISIBILlTY

Hazard

Visibility hazards occur when a machine operator is unable to see properly. Obstructions on machines (Figure Vl1 ) or the location of the operator's station may block the view. Saddle tanks on tractors may prevent the operator from seeing objects in front or to the side. A large trailer or implement may block the operator's view to the rear. Combine operators, or operators of other large machines, may have a poor view to the rear of their machines (Figure Vl2).

Possible Injuries

Lack of visibility does not result in an injury by itself. However, poor visibility may cause an operator to unknowingly do something unsafe that could cause injury or damage.

Preventive Measures

Pay attention to the way equipment is mounted. See if another option will serve just as well and restore operator visibility. Use mirrors to enhance your view of the rear or other areas. Consider installing backup alarms on equipment.

Figure Vl1 (below left). Bale falling as a result of hitting an unseen structure.

Figure Vl2 (below right). Worker on ground unseen by combine operator.

THROWN OBJECTS

Hazard

Machine components that rotate at high speeds can pick up objects and throw them with great force for long distances. Rotary cutters or mowers often throw rocks, glass, or gravel (Figure T01). Fans may pick up grain or other debris. Compressed air can blow dirt or grit into the eyes (Figure T02). Chain saws and other power tools can throw chips toward the face and eyes. String trimmers can throw sand, glass, and gravel.

Possible Injuries

Objects thrown at the body can easily cause puncture wounds, bruises, or lacera- tions. Objects thrown into the eye can permanently damage the eye and may result in blindness.

Preventive Measures

Keep moving components shielded. Discharge chutes or chain deflectors on mowers are designed to absorb energy or deflect thrown objects. Covers, screens. Or diffusers are available for fans and air compressors. Wear safety glasses or a face shield while working with this type of equipment, and stay away from dis- charge areas when possible.

Figure T01 (below). Rotary mower throwing debris.

Figure TO2 (right). Objects thrown at the face.

ENERGY RELEASE

Hazard

Energy can be released suddenly, unexpectedly, or uncontrolledly. Hydraulic fluid escaping from a pressurized system is an example of energy release (Figure ER1). A spring can release energy if it breaks or slips out of its mounting while under load. Contact with electrical wires can cause a dangerous release of electrical energy (Figure ER2). Raised loads store potential energy that can be released if a latch or fastener fails, allowing the object to fall on someone. Handles or levers used to lift or control heavy loads or forces may unlatch or slip and strike someone (Figure ER3).

Possible Injuries

The sudden release of energy from a spring can throw an object against an opera- tor, resulting in injury. Fluid under pressure squirting through a small hole can penetrate the skin and enter the bloodstream, causing poisoning. Dangerous electrical voltages can cause electrocution. Grain dust can be explosive under certain conditions. Objects that rotate at high speeds, such as blades, wheels, or free-spinning winch handles, are all forms of energy release. Excessive speed on chains, belts, or shafts may cause them to break and throw objects at the operator or severely damage the machine itself, making it unsafe.

Preventive Measures

Before working around objects that store energy, safely release the energy by setting controls to neutral and turning off the power. Lower raised loads to the ground or support them with safety bars or pins. Check valves, controls, and switches to be sure that all energy has been safely released. Replace belts, chains, shafts, and gears when they are worn. Avoid excessive speed on all components.

Figure ER1 (below right). High-pressure fluid break.

Figure ER2 (below center). Energy released by touching electrical lines.

Figure ER3 (below left). Energy release by moving handle or lever.

FALLS

Hazard

Standing on slippery or cluttered surfaces or losing your grip or balance can lead to falls and injuries. Mud, oil, or water on a platform (Figure FA1 ) can make it slippery and quite hazardous. Riding on the fender, drawbar, or platform of a machine rather than the seat also poses a serious hazard (Figure FA2).

Possible Injuries

Falling can result in injury if you land on a hard surface or a sharp tool. Falling into water can result in drowning. Falling from a moving tractor or other machine can lead to a number of other hazards as the machine passes over you.

Preventive Measures

The safest place to ride on a machine is in the operator's seat. If the machine has a rollover protective structure (ROPS), use your seat belt as well. The seat belt is designed to hold you safely in the seat as you operate the machine. Do not allow extra riders on the machine! Remove all loose tools or objects from equipment decks or platforms. Keep surfaces free of mud and debris to avoid slipping.

Figure FA1 (below right). Falls caused by slippery surfaces.

Figure FA2 (below left). Falling from machinery.

SPEED

Hazard

Unlike automobiles, agricultural machines are not designed for high speeds. High speeds on the road or in the field can make a tractor or other machine unstable (Figure SP1 ) and can lead to an overturn. A slow-moving machine can be like a brick wall if a fast-moving car collides with it on the highway.

Possible Injuries

Excessive speed can result in tractor overturn, especially in sharp turns or on rough ground. When driving too fast, the operator has less time to react to events. Driving a machine too fast on rough ground may cause the operator to be thrown from the machine, which can lead to other hazards.

Preventive Measures

If you must drive agricultural equipment on highways, use slow-moving-vehicle (SMV) emblems (Figure SP2) and other appropriate marking or lighting. On rough ground, drive slowly and keep the tractor under control at all times.

Figure SP1 (below left). High speeds make machines hard to control.

Figure SP2 (below right). SMV emblem warns about slow vehicle in the road.

ENVIRONMENT

Hazard

The work environment in or on a machine poses many potential hazards. Included are extremes of surface and air temperatures, high humidity, and lack of ventilation. Radiators and mufflers on machines are good examples of dangerously hot surfaces (Figure EN1). Cold surfaces can be found around air-conditioning and gas-handling equipment. Air temperature, humidity, and ventilation all affect a worker's productivity and alertness.

Possible Injuries

Contact with extremely hot or cold surfaces can cause painful injuries to the body, as described in Table EN1. Air temperature, humidity and ventilation rates affect worker performance. Temperature extremes and high humidity force the body to work harder to maintain its optimum status. Lack of ventilation can increase opera- tor discomfort and lead to a buildup of toxic gases. Table EN2 provides some desirable ranges to consider.

Preventive Measures

Good design of the operator environment, cab, or platform and proper selection of clothing will help to ensure peak performance from operators and their machines.

Table EN1. Skin Contact Effects

Table EN2. Desirable Environmental Conditions

CUMLATIVE TRAUMA

Hazards

Many engines and machines produce dangerous noise and vibration levels. The operator is often seated or standing close to the source of noise. Vibration is transmitted to the body through the feet, buttocks, hands, and arms. Tractors, combines, chain saws, and other powered machines produce vibration. Many jobs require repeated stressful motion of the hands, arms, legs, or back.

Possible Injuries

Vibration, noise, and repetitive motion cause nerve and muscle damage. Vibration in excess of the body's tolerance can impair nervous and circulatory function or lead to motion sickness (Table CT1). Prolonged exposure to excessive noise (Table CT2) can lead to permanent hearing loss. Repetitive motions lead to joint injury (Table CT3) or to fatigue that reduces the operator's performance. Repetitive motion causes pain in the joints of the arms, legs, or back.

Preventive Measures

Pay close attention to the design of equipment, particularly how the operator relates to or interacts with the machine. If noise levels are hazardous, use hearing protectors—ear plugs or ear muffs—that can reduce noise by up to 20 decibels (db). Gloves can help reduce vibration to the hands. A well-designed, properly adjusted seat is a must to minimize whole-body vibration. Reducing the speed or force needed for a job protects against repetitive motion disorders.

Table CT1. Vibratlon Exposure and Effects

Table CT2. Allowable Noise Exposure

Table CT3. Repetitive Motion Disorders

ROLLOVER

Hazards

Tractors or other machines, when pushed beyond their limits, can roll over or overturn onto the operator or nearby persons (Figures R01 and R02). Rollovers can result from a number of factors:

Sloping terrain
Rapid acceleration
H igh speed
Sharp turns
Light front end GS
Heavy loads supported on the hitch
Load improperly hitched Loads carried improperly
Unstable ground
Contact with stumps or rocks

Possible Injuries

If a tractor or other machine rolls over, the operator can become trapped under the machine and crushed, resulting in severe injury or death.

Preventive Measures

Any tractor manufactured since October 25, 1976, should be equipped with a rollover protective structure (ROPS) unless it was designed for orchard or feedlot use. Many older machines can be fitted with a ROPS as well. Check with your manufacturer about availability. If your tractor has a ROPS, be sure to wear your seat belt. Hitch loads properly, maintain safe speeds, and operate with caution at all times.

Figure R01 (below left). Machine rollover.

Figure R02 (below right). Tractor rollover.

Evaluating Hazards

Equipment owners and operators can gain practice in recognizing hazards by evaluating their machines for hazards. This process is also useful for comparing machines to see which one offers the best protection or to determine what improve- ments should be made. The form on the following page provides a simple approach to evaluating hazards. The procedure shown here is only one of many methods available and is not intended to be a thorough assessment. It is intended to allow each individual to evaluate a situation as he or she perceives it.

To use the procedure, first identify and record the manufacturer, model, serial number, and intended use of the machine you are studying. Carefully look over the machine and try to identify as many of the hazards as you can. List these hazards on the form as shown in the example below. Then study each hazard and rate it according to the seriousness of its consequences (3=high, 2=moderate, 1=low). For example, a hazard that may cause serious injury or death should be rated high (3). A hazard that would result in a minor injury should be rated low (1 ) Then rate the probability of exposure associated with each hazard that is, the likelihood (3=high, 2=moderate, 1 =low) that an operator would be exposed to the hazard during routine operation or any foreseeable use of the machine. For each hazard identified, multiply the hazard rating by the probability rating to get a risk rating. Then add the risk ratings for the machine to get an overall relative safety index. The lower the number, the safer the machine.

TRACTOR AND ROTARY MOWER

Note: Values used in the example are for illustration only. Each user should rank hazards as he or she perceives them. This example may not include all hazards present in the example operation.

LEGAL OBLIGATIONS

Agricultural employers have certain legal obligations under the Occupational Safety and Health Act (OSHA) and the Fair Labor Standards Act (FLSA). A summary of the OSHA and FLSA provisions are given along with many other labor guidelines in Cooperative Extension Service publication AG-444, North Carolina Farm Labor Rules and Regulations. Farm owners and managers should review the OSHA and FLSA requirements and use positive measures to prevent accidents.

OSHA regulations pertaining to agricultural machinery include sections on slow-moving vehicles, rollover protection, and safety for field and farmstead machinery, among other topics. The act also requires that employees who operate tractors and machinery be informed of safe operating practices when initially assigned and at least annually thereafter. An example of these instructions is provided in the box below. It is a myth that OSHA regulations do not apply to agriculture. It is true that farms with fewer than 11 employees are exempt from inspections and some record-keeping requirements, but in general OSHA regulations apply to any operation that has one or more employees. (Immediate family members are not considered employees.)

Tractor and Equipment Operating Instructions for Employees

FLSA regulations establish minimum ages for children employed in jobs that are considered hazardous. Hazardous occupations related to machinery include:

Operating a tractor of over 20 horsepower;
Operating or assisting in operating a corn picker, cotton picker, grain combine, hay mower, forage harvester, hay baler, potato digger, feed grinder, crop dryer, mobile pea viner, forage blower, auger conveyor, self-unloading wagon, power posthole digger, power post driver, or nonwalking rotary tiller;
Operating a trencher, earth-moving equipment, forklift, potato combine, or power-driven circular, band, or chain saw;
Harvesting or loading timber with a butt diameter of more than 6 inches;
Driving a bus, truck, or automobile when transporting passengers;
Working in a horizontal silo while operating a tractor for packing purposes;
Handling, transporting, or applying anhydrous ammonia and chemicals identified by the words DANGER and POISON.

The minimum age requirement for most occupations is 16 unless certain exemp- tions apply. Farm operators should carefully review these requirements and the exemptions if minors are employed.

References

Eickhoff, W. D., North Carolina Farm Labor Rules and Regulations, Publication AG- 444, North Carolina Cooperative Extension Service, Raleigh, N.C. 1991.

Roberts, D. L., A Guide to Farm Safety and Health, NC-OSHA Industry Guide No. 10, Division of Occupational Safety and Health, North Carolina Department of Labor, Raleigh, N.C. 1990.

Roberts, D. L., and W. J. Becker (Eds.), Human Factors: A Series of Quality Instructional Materials, American Society of Agricultural Engineers, St. Joseph, Mich. 1991.

Agricultural Safety, 3rd ed., Deere & Company Service Training, Moline, III. 1987.