The growing and gathering of crops and production of livestock has long been recognized as one of the world’s oldest and most important occupations. Farming and ranching today is as diverse as the many crops, fibres and livestock which are produced. At one extreme, the farming unit may consist of a single family that cultivates the soil and plants and harvests the crop, all by hand over a limited area. The opposite extreme includes large corporate farms spanning vast areas that are highly mechanized, using sophisticated machinery, equipment and facilities. The same is true for the storage of food and fibre. Storage of agricultural products may be as rudimentary as simple huts and hand-dug pits, and as complex as towering silos, bunkers, bins and refrigerated units.
Hazards and their prevention
Agricultural products such as grains, hays, fruit, nuts, vegetables and plant fibre are often stored for later human and livestock consumption or sale to the general populace or to manufacturers. The storage of agricultural products prior to shipment to market may occur in a variety of structures—pits, bunkers, bins, silos, refrigerated units, carts, wagons, barns and railroad cars, to mention a few. Despite the diversity of products being stored and of storage facilities, there are hazards which are common to the storage process:
Falls and falling objects
Falls may occur from heights or at the same level. In the case of bins, silos, barns and other storage structures, falls from heights most often occur from and in storage structures. Most often the cause is unguarded roofs, floor openings, stairways, lofts and shafts, and climbing ladders or standing on raised work areas such as an unprotected platform. Falls from height may also result from climbing on or off the transportation unit (e.g., wagons, carts and tractors). Falls from the same level occur from slippery surfaces, tripping over objects or being pushed by a moving object. Protection against falls includes such measures as:
- provision of safety belts, harnesses, lifelines and safety boots
- installation of guard rails, toeboards, cat-ladders or crawling boards on sloped roofs
- guarded floor openings, lofts and shafts
- use of the standard rise and run of stairways, provision of handrails on both sides, and application non-skid strips where necessary
- maintaining floors in good condition, free from uneven surfaces, holes and accumulations of waste or slippery substances
- provision of handholds on permanent ladders, guard platforms and landings
- maintaining extension or step ladders in good condition and training employees on their use.
Agricultural products may be stored loose in a facility or bundled, bagged, crated or bailed. Loose storage is often associated with grains such as wheat, corn or soybeans. Bundled, bagged, crated or bailed products include hay, straw, vegetables, grains and feeds. Falls of materials occur in all types of storage. Collapse of unsecured stacked foodstuffs, overhead materials and piles of goods are often causes of injury. Employees should be trained in the correct stacking of goods to prevent their collapse. Employers and managers must monitor the workplace for compliance.
Agricultural products may be stored in two types of facilities—those that contain enough oxygen to sustain life, such as barns, open carts and wagons, and those that do not, such as some silos, tanks and refrigeration units. The latter are confined spaces, and should be treated with appropriate precautions. The oxygen level should be monitored prior to entry and a supplied air or self-contained breathing unit used if necessary; someone else should be on hand. Suffocation may also occur in either type of facility if the goods which it contains have the characteristics of a fluid. This is commonly associated with grains and similar foodstuffs. The worker dies as a result of drowning. In grain bins it is a common practice for an agricultural worker to enter the bin due to difficulties in loading or unloading, often caused by a condition of the grain resulting in bridging. Workers attempting to alleviate the situation by unbridging the grain may voluntarily walk on the bridged grain. They may fall in and be covered with the grain or be sucked under if the loading or unloading equipment is operational. Bridging also may occur to the sides of such structures, in which case a worker may enter to knock down the material sticking to the sides and become engulfed when the material fails. A lockout/tagout system and fall protection such as a safety belt and rope are essential if workers are to enter this type of structure. Children’s safety is of special concern. Often inquisitive, playful and wanting to do adult chores, they are attracted to such structures, and the results are all-too-often fatal.
Fruit and vegetables are often kept in cold storage prior to shipping to market. As indicated in the above paragraph, depending on the type of unit, cold storage may be considered a confined space and should be monitored for oxygen content. Other hazards include frostbite and cold-induced injury or death from body temperature loss following prolonged exposure to cold. Personal protective clothing should be worn appropriate to the temperature within the cold-storage unit.
Gases and poisons
Depending on the moisture content of the product when it is placed in storage and atmospheric and other conditions, feeds, grains and fibres may produce dangerous gases. Such gases include carbon monoxide (CO), carbon dioxide (CO2) and oxides of nitrogen (NOx), some of which may cause death in a matter of minutes. This is also especially important if the goods are stored in a facility in which nonlethal gases may be allowed to accumulate to dangerous levels, displacing oxygen. If the potential for gas production exists, then monitoring for gases should be done. In addition, foods and feeds may have been sprayed or treated with a pesticide during the growing period to kill weeds, insects or disease, or during the storage process to reduce spoilage or mould, spore or insect damage. This may add to the hazards of gas production, inhalation of dusts and handling of the product. Special care should be taken by workers to wear PPE depending on the nature and longevity of the treatment, the product used and the label directions.
Storage facilities may contain a variety of machinery for conveying the product. These range from belt and roller conveyors to blowers, augers, slides and other such product-handling devices, each with its own power source. Hazards and suitable precautions include:
- Nip points formed by belts, pulleys and gears. Agricultural workers should be protected from nip and shear points by an appropriate guarding around the point of potential contact.
- Protruding belt fasteners, setscrews, keys, bolts and grooves. Protruding setscrews, keys or bolts on revolving shafts should be countersunk, encased or shrouded. Belt fasteners should be inspected and repaired.
- Shear points caused by flywheel arms, augers and their housing, pulley spokes, crank and lever mechanisms. These should be guarded or enclosed.
- Contact with moving transmission or electrical elements. These should be guarded or enclosed.
- Inadvertent starting of machinery or equipment. A system for locking out or tagging out equipment prior to maintenance or repair should be implemented and enforced.
- Loose clothing or hair getting wound on or caught by shafts. Clothing that is loose, frayed or that has hanging threads should never be worn. Other personal protective apparel and shoes appropriate to the job task should be worn.
- Excessive noise. Noise exposure should be monitored and administrative, engineering and/or personal protective controls should be taken if necessary.
Employees should be trained and aware of the hazards, basic safety rules and safe working methods.
Agricultural workers who are involved in the handling of agricultural products for storage are at risk for respiratory disorders. Exposures to a variety of dusts, gases, chemicals, silica, fungal spores and endotoxins can result in damage to the lungs. Recent studies link lung disorders caused by these substances to workers who handle grain, cotton, flax, hemp, hay and tobacco. Therefore the populations at risk are worldwide. Agricultural lung disorders have many common names, some of which include: occupational asthma, farmer’s lung, green tobacco sickness, brown lung, organic dust toxic syndrome, silo filler’s or unloader’s disease, bronchitis and airway obstruction. Symptoms may first manifest themselves as being characteristic of influenza (chills, fever, coughing, headaches, myalgias and breathing difficulty). This is especially true for organic dusts. Prevention of lung dysfunction should include an assessment of the worker’s environment, health promotion programmes targeted at primary prevention and the use of personal protective respirators and other protective devices based on the environmental assessment.
Although it may seem simple, the transportation of goods to market is often as complex and hazardous as growing and storing the crop. The transportation of products to market is as diversified as the types of farming operations. Transportation may range from goods being carried by humans and livestock, to being transported by simple mechanical devices such as bicycles and animal-drawn carts, being hauled by complex mechanical equipment such as large carts and wagons pulled by tractors, to the use of commercial transportation systems, which include large trucks, buses, trains and airplanes. As the world’s population increases and urban areas grow, road travel of agricultural equipment and implements of husbandry has increased. In the US, according to the National Safety Council (NSC), 8,000 farm tractors and other agricultural vehicles were involved in highway accidents in 1992 (NSC 1993). Many farming operations are consolidating and expanding by acquiring or renting a number of smaller farms which are typically scattered and not adjoining. A 1991 study in Ohio showed that 79% of the farms surveyed operated in multiple locations (Bean and Lawrence 1992).
Hazards and their prevention
Although each of the modes of transportation mentioned above will have its own unique hazards, it is the intermix of civilian traffic with agricultural transport machinery and equipment that is of major concern. The increase in road travel of agricultural equipment has resulted in a greater number of collisions between motor vehicles and slower moving agricultural equipment. Farm equipment and implements of husbandry may be wider than the width of the road. Due to pressure of planting at the right time to assure a crop or harvesting and getting the crop to a market or storage location as quickly as possible, agricultural machinery must often travel on the roadways during periods of darkness, early morning or evening.
An in-depth study of all 50 states’ codes in the United States revealed that the lighting and marking requirements vary greatly from state to state. This diversity in requirements does not communicate a consistent message to motor vehicle drivers (Eicher 1993). Faster speeds of other vehicles combined with inadequate lighting or marking of agricultural equipment is often a deadly combination. A recent study in the United States found that the common accident types are rear end, sideswipe-meeting, sideswipe-passing, angle, head-on, backing and other. In 20% of the 803 two-vehicle crashes studied, the farm vehicle was struck from an angle. In 28% of the crashes, the farm vehicle was sideswiped (15% meeting and 13% passing). Twenty-two per cent of the accidents consisted of rear-end (15%), head-on (4%) and backing (3%) collisions. The remaining 25% were crashes which were caused by something other than a moving vehicle (i.e., a parked vehicle, pedestrian, animal and so on) (Glascock et al. 1993).
Livestock are used in many parts of the world as the “horsepower” to transport agricultural products. Although beasts of burden are generally reliable, most are colourblind, have territorial and maternal instincts, react independently and unexpectedly, and are of great strength. Such animals have caused vehicle crashes. Falls from agricultural machinery and implements of husbandry are common.
The following general safety principles apply to transportation operations:
- Local traffic rules, regulations or laws should be learned and obeyed.
- No riders or passengers other than those that are necessary to accomplish the transport and unloading duties should be permitted.
- Vehicles should stay as close to the shoulder of the road as road conditions will allow.
- Passing other vehicles (moving or parked) and pedestrians must be done with caution.
- Broken-down vehicles should be moved off the road if possible.
- All marking and lighting on machinery and equipment should be maintained and clean.
- Driving should never be done under the influence of alcohol or drugs.
Laws and regulations may dictate the state of acceptable lighting and marking. However, many such regulations only describe the minimal acceptable standards. Unless such regulations specifically prohibit retrofitting and adding additional lighting and marking, farmers should consider adding such devices. It is important that such lighting and marking devices be installed not only on self-propelled implements but also on pieces of equipment that they may be pulling or trailing.
Lights are especially critical for dusk, dawn and night-time movement of agricultural equipment. If the agricultural vehicle has a power source, consideration should be given to having, at a minimum: two headlights, two tail-lights, two turn signals and two brake lights.
Tail-lights, turn signals and brake lights may be incorporated into single units or can be attached as separate entities. Standards for such devices may be found through standard-setting organizations such as the American Society of Agricultural Engineers (ASAE), the American National Standards Institute (ANSI), the European Committee for Standardization (CEN) and the International Organization for Standardization (ISO).
If the agricultural vehicle does not have a power source, battery-powered lights, although not as effective, may be used. Many such lights are commercially available in a variety of types (flood, blinking, rotating and strobe) and sizes. If it is impossible to obtain these devices, then reflectors, flags and other alternative materials discussed below may be used.
Many new retroreflective fluorescent materials are available today to aid in marking agricultural vehicles for enhanced visibility. They are manufactured in patches or strips in a variety of colours. Local regulations should be consulted for acceptable colours or colour combinations.
Fluorescent materials provide excellent daytime visibility by relying on solar radiation for their light-emitting properties. A complex photochemical reaction takes place when the fluorescent pigments absorb non-visible solar radiation and re-emit the energy as a longer wavelength of light. In a sense, fluorescent materials appear to “glow” in the daytime and appear brighter than the conventional colours in the same light conditions. The primary disadvantage of fluorescent materials is their deterioration with prolonged exposure to solar radiation.
Reflection is an element of sight. Wavelengths of light strike an object and are either absorbed or bounced back in all directions (diffused reflection) or at an angle exactly opposite to the angle at which the light struck the object (specular reflection). Retroreflectivity is very similar to specular reflection; however, the light is reflected directly back toward the light source. There are three primary forms of retroreflective materials, each having a different degree of retroreflectivity based on how they were manufactured. They are presented here in increasing order of retroreflectivity: enclosed lens (often called engineering grade or Type ID), encapsulated lens (high intensity) and cube corner (diamond grade, prismatic, DOT C2 or Type IIIB). These retroreflective materials are excellent for night-time visual identification. These materials are also of great assistance in defining the extremities of agricultural implements. In this application, strips of retroreflective and fluorescent material across the width of the machinery, front and back, best communicate to drivers of other, nonagricultural vehicles the actual width of the equipment.
The distinctive red triangle with a yellow-orange centre is used in the United States, Canada and many other parts of the world to designate a class of vehicles as “slow moving”. This means the vehicle travels less than 40 km per hour on the roadway. Typically, other vehicles travel much faster, and the difference in speed may result in a misjudgement on the part of the faster vehicle driver, affecting the driver’s ability to stop in time to avoid an accident. This emblem or an acceptable substitute should always be used.
Agricultural workers who are involved in the transportation of agricultural products may be at risk for respiratory disorders. Exposures to a variety of dusts, chemicals, silica, fungal spores and endotoxins may result in damage to the lungs. This is somewhat dependent on whether the transport vehicle has an enclosed cab and whether the operator engages in the loading and unloading process. If the transport vehicle has been used in the process of pesticide application, pesticides could be present and trapped inside the cab unless it has an air filtration system. Nevertheless, symptoms may first manifest themselves as being characteristic of influenza. This is especially true for organic dusts. Prevention of lung dysfunction should include an assessment of the worker’s environment, health promotion programmes targeted at primary prevention and the use of personal protective masks, respirators and other protective devices.