Take steps to make sure ground conditions are stable before entering the work area.

The accident: On June 20, 2009, a 52-year-old miner with 25 years of experience was fatally injured while washing a face drill. He and a second miner were washing the unit when they heard popping sounds. The second miner said they thought the noise was coming from the elevated boom on the drill as the hydraulics bled off. The second miner reported then hearing two loud noises and feeling a rush of air. When he turned around, the roof had fallen, burying the first miner, the drill, and other equipment. The first miner was pronounced dead when his body was recovered and brought to the surface. His death was attributed to crushing injuries.

The bottom line: The accident occurred because the ground support system for the mine was not adequately designed, installed, and maintained to control the ground where miners worked and traveled. The roof rock broke below the anchorage zone of the roof bolts and pulled several of them out of the roof, leaving the expansion shells in the bolt holes. The fallen roof was about 50 feet long by 20 feet wide and up to 3 feet thick.

The applicable standard

30 CFR § 57.3360

Ground support use.

Scaling and Support — Underground Only

Ground support shall be used where ground conditions, or mining experience in similar ground conditions in the mine, indicate that it is necessary. When ground support is necessary, the support system shall be designed, installed, and maintained to control the ground in places where persons work or travel in performing their assigned tasks. Damaged, loosened, or dislodged timber used for ground support which creates a hazard to persons shall be repaired or replaced prior to any work or travel in the affected area. AM

Best practices

• When ground conditions create a hazard to persons, install effective ground support before other work is permitted in the affected area.

• Design, install, and maintain a support system to control the ground in places where persons work or travel.

• Examine and test ground conditions in areas where work is to be performed prior to work commencing and as ground conditions warrant during the shift.

• Be alert to any change of ground conditions.

• Identify and scale loose ground from a location which will not expose persons to falling material.

Information from this Safety Watch is from an actual accident and is provided by the Mine Safety and Health Administration. It is meant for general information purposes only.

Construct barricades and post signage to warn operators about dangerous conditions.

The accident: On May 3, 2008, a 51-year-old mine owner with 45 weeks of experience was fatally injured when the excavator he was operating fell into an 8-foot-deep sump hole. The owner/operator was attempting to clean a clogged ditch to drain water from the pit following heavy rains. The sump hole had previously been dug into the pit floor to drain water. The pit floor was covered by several feet of water, however, and the sump hole was not visible. The owner/operator was working alone when one of the excavator’s crawler tracks fell into the sump hole. The excavator fell on its side, trapping the miner inside the cab. His death was attributed to asphyxiation.

The bottom line: Upon learning of the accident from local media reports two days later, Mine Safety and Health Administration investigators inspected the site and found that all hazards were not identified to ensure safe performance of tasks. Warning signs — visible from all approaches — were not erected to warn of a hazard. Barricades had not been erected to prevent access to the hazardous conditions.

The applicable standard

30 CFR § 56.1009

Suspended loads.

Areas where health or safety hazards exist that are not immediately obvious to employees shall be barricaded, or warning signs shall be posted at all approaches. Warning signs shall be readily visible, legible, and display the nature of the hazard and any protective action required.

Best practices

• Examine working places, identify hazards, and assess and control risks. Be alert to changing conditions. Maintain a safe distance from the edge of excavations and slopes. If the safety of travelways cannot be positively determined, do not travel on them.

• Where hazards in the travelways are not clearly distinguishable or immediately obvious, install barriers, markers, or other warning devices to aid equipment operators and limit travel of mobile equipment.

• Ensure all miners are trained to recognize workplace hazards, specifically the limited visibility inherent to the operation of large equipment.

• Wear seat belts when operating self-propelled mobile equipment.

Sponsored by

Suspended loads carry considerable risk. Stay a safe distance away.

The accident: On April 21, 2009, a 51-year-old contract laborer with three years of experience — two weeks and three days of experience at this operation — was fatally injured while working inside an excavation ditch as an excavator maneuvered a concrete block into place. The chain that attached a four-leg sling from the box to the excavator broke, and the box fell into the ditch, striking and crushing the victim. His death was attributed to multiple blunt force trauma.

The bottom line: Upon inspection, Mine Safety and Health Administration investigators found that, while the quadruple-leg sling used to move the concrete block was adequately rated for the load, the 3/8-inch connector chain lacked any identifying marks that would indicate it was the appropriate grade of material. The connector chain exhibited wear and was distorted in several locations. Wear included bent links, rust accumulation, and corrosion pitting. A single link in the working section of the chain failed, causing the catch basin to fall. Additionally, inspectors noted that the victim was working in an area where he could not stay clear of the suspended load.

The applicable standard

30 CFR § 56.1009

Suspended loads.

Persons shall stay clear of all suspended loads.

Best practices

• Identify hazards associated with the task to be performed, review those hazards with all personnel involved, and implement measures to ensure persons are properly protected.

• Communicate lift plans to all persons working in the lift zone to ensure that no one is under a suspended load.

• Stay clear of a suspended load.

• Attach taglines to loads that may require steadying or guidance while suspended.

• Use sling or chain assemblies (rigging) specifically intended for lifting and adequately rated for the loads being lifted.

• Carefully inspect all rigging prior to each use.

Information from this Safety Watch is from an actual accident and is compiled from Mine Safety and Health Administration reports. It is meant for general information purposes only.

Sponsored by

Wearing jewelry is hazardous to miners who work with machinery and power tools. A conveyor belt or pinch point can pull a finger off with a ring, causing severe injury and disfigurement. According to recent Department of Labor statistics, more than 11,000 people are hurt in accidents involving jewelry each year; almost 90 percent are male.

Other government statistics indicate that the fourth major cause of on-the-job injury is machine-related accidents – getting caught by moving machine parts. Although mechanics, machine operators, electricians, laborers, and truck drivers were the higher risk occupations, anyone working in the mining industry is potentially at risk.

Accepted guidelines for working around moving equipment – any machine that rotates, slides, or presses – are that miners should always use safety shields, guards, and lock-out procedures and never wear jewelry or loose-fitting clothing that could get caught in the moving equipment. A dangling necklace is an obvious hazard, but even a wedding ring can get caught.

Wedding rings are the source of some hang-ups – both literally and figuratively. Wedding bands, even if relatively narrow and tight fitting, still cause accidents, but some people believe that they should always wear their wedding rings as sacred symbols of marriage. Some spouses pressure their mates to wear their rings. Some people who remove their rings for work also often lose them and this causes marital strife. This is the primary reason that the government strongly recommends that workers not wear jewelry rather than officially banning it. Whether or not to wear a wedding ring remains a personal choice, but, clearly, a ring-less spouse is better than a fingerless one, or worse.

The Occupational Safety Health Administration’s regulations covering machine guarding or hand and portable power tools do not forbid workers from wearing jewelry to work, although many safety publications advise employers and workers to ensure that workers aren’t wearing jewelry when operating these kinds of devices – even when also wearing gloves.

As part of the general duty clause to protect workers, Section 5, of the Occupational Safety and Health Act, employers are held responsible for the safety of their workers, which can be interpreted to extend to warning them of the hazards of wearing jewelry and loose clothing. The clause reads:

A.    Each employer:

• Shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or likely to cause death or serious physical harm to his employees;
• Shall comply with occupational safety and health standards promulgated under this Act.

B.     Each employee shall comply with occupational safety and health standards and all rules, regulations, and orders issued pursuant to this Act which are applicable to his own actions and conduct.

If the employer recognizes that wearing loose chains, jewelry, loose clothing, or other items is likely to cause serious harm, he is obligated to address this hazard under the general duty clause through training and communication. A training program should provide guidelines for safe operation of machinery and power tools, including straightforward advice about not wearing jewelry or loose clothing of any type. Any dangling object is a major safety issue around power tools.

A recent issue of Safety Smart! recommends the following precautions:

• Wear snug clothing when working around moving machinery. Button sleeves and tuck in shirts and pant legs. Avoid wearing scarves and drawstrings. Be aware that even gloves can present an entanglement hazard.
• Never wear jewelry. The hazards of neck chains are obvious, but even a ring can catch and result in amputation of a finger or a worse injury.
• Long hair should be tied or restrained with a hairnet. Hair simply tucked inside a hard hat can come loose and get caught in moving parts. Even a long beard can be a hazard in a machine work environment.
• Make sure all equipment is properly guarded to prevent entanglement and other machine injuries. Report any missing or defective guards and shields to your supervisor.
• Never remove or block a machine guard.
• When doing adjustment or repairs, follow the correct lockout and tagout procedures, and replace guards before returning the machine to service.
• Know how to quickly locate the emergency stop and start controls on all machinery in your work area.

Information contained in this article was provided through the Safety & Health Committee of the National Stone, Sand & Gravel Association.

An official danger sign may not be there. Your job requires that you go on a roof, and you suspect that the roof won’t hold. Advice: Don’t put yourself at risk; don’t go there. Awareness of your work area, wherever or whatever it may be – even if a roof – is critical to your safety. Falls through roofs are common, and injuries that result from falls are usually serious, often fatal. Any work on a roof is a risk.

Don’t start work, whether it’s maintenance or any other type of work, if you think it will be necessary to:

• Go onto a roof that is or looks fragile;
• Go onto a structure with an unprotected edge more than 6 feet high;
• Climb onto or over a plant structure, such as a crusher or electric motor, which will put you above the edge protection; or
• If you think that you make be at risk in any way.

A subcontractor was recently injured when he fell through a fragile roof. He had stepped out onto the plywood roof to pull welding cables up the plant. The plywood gave way, and he fell through to his chest. If he had not been caught at the chest, he would have fallen 15 feet to the ground.

Good advice for workers is simply not to go out onto a roof unless you know that the risk has been assessed, the work properly planned, and safe work practices established. Work can be done safely on a fragile roof if ladders, crawl boards, toe board or other edge protection, guardrails, and even fall protection equipment, such as safety harnesses, if necessary, are being used.

Fragile materials will not safely support the weight of a person and any heavy loads they may be carrying. Fragility does not depend solely on the composition of the material of the roof, but also thickness, span between supports, sheet profile, type of fixings, design, and age. Sometimes an entire roof is fragile, and sometimes only parts, such as roof lights, are fragile. Sometimes fragility is disguised, such as in the case of an old roof that has been newly painted.

Fragile roofing materials can fracture without warning. Factures can occur so rapidly that someone could easily fall through the fragile roofing material, suffering serious or even fatal injuries. You should assume that a roof is fragile until it has been determined that it is not fragile.

Before going to work on a roof or using a roof as a means of access to get to another area, you should verify that your employer has identified hazards and assessed risks. Before assigning roof work, employers must consider all factors of that work that may affect the health and safety of workers. These factors include the following:

• Inspect perimeter walls for warning notices;
• Inspect roof to determine the presence, condition, and extent of fragile components and the general structural integrity of the roof, including cladding and supports, and distribution of load;
• Skylights must be secured with safety wire mesh above and below each fixture, and they should be inspected regularly;
• Post appropriate warning signs at access points if roof is fragile;
• Check the existence and condition of safety mesh;
• Verify a safe means of getting up and down; and
• During harsh weather, including rain, snow, ice, or wind, roofing material conditions may change. A thorough inspection must be done.

The nature of the precautions needed to work safely on a roof will vary from job to job. As for all jobs, however, employers must ensure that workers assigned to roof jobs are trained in the particularities of the work – that they have the knowledge, skills, and experience to work safely – on a roof – and that they are aware of fragile areas and how to work around them. General safety rules for working on a fragile roof include the following:

• Look for and heed signs such as “Danger Fragile Roof” and “Use Crawl Boards” that may be posted at access points to the roof;
• Use appropriate access equipment, whether crawl boards, roof ladders, walkways, and/or planks;
• Use appropriate fall arrest gear – safety harnesses attached to suitable anchorages – when you must work near fragile roof material;
• Do not walk upright on a fragile roof unless appropriate equipment is in place;
• Keep roof work areas clear of debris and clutter that could cause a trip and fall; and
• Wear suitable shoes that control slipping.

Information contained in this article was provided through the MSHA-NSSGA Alliance and was written cooperatively by members of both the aggregates industry and the regulatory agency.

Strokes can happen anywhere, anytime. They are the number one cause of serious, long-term disability in the United States, affecting 750,000 Americans annually, and the third leading cause of death after heart disease and cancer, according to statistics compiled and published by the Stroke Awareness Organization of Southern California (SOCAL). Certain individuals may be more prone to stroke than others, but strokes can happen to anyone – to someone who seems healthy and doesn’t appear to have health problems.

What is a stroke?

A stroke is what happens to a person’s body when part of the brain is cut off from its blood supply and stops working, usually because one of the arteries that supplies oxygen-carrying blood to the brain has been damaged. Most strokes are one of two types, reports the National Stroke Association. The most common (85 percent) is an ischemic stroke, caused by blockage of a blood vessel in the brain, usually by a blood clot or by fatty deposits on the vessel wall. In 15 percent of cases, a stroke is caused by a burst vessel or hemorrhage. A ruptured blood vessel prevents normal flow and allows blood to leak into brain tissue, destroying it.

Part of the brain, deprived of oxygen, could be destroyed within minutes, but other tissue parts may be damaged and destroyed over longer period of time, up to several hours, depending on the extent of blockage or hemorrhage. That is why it is important to determine if a person’s symptoms align with those of a stroke and, if they do, to seek medical help immediately. Recognizing the symptoms and acting fast can save a life and limit disabilities.

Warning signs of stroke

Various medical resources and stroke awareness groups list the following early symptoms of a stroke:

• Sudden numbness or weakness in face, arm, hand, or leg, especially on one side of the body;
• Sudden confusion, trouble speaking or understanding;
• Sudden trouble seeing in one or both eyes;
• Sudden trouble walking, dizziness, loss of balance or coordination; and
• Sudden, severe headache with no known cause.

What to do first

How do you recognize a stroke? Sometimes symptoms of a stroke are difficult to identify, but anyone can identify key early symptoms by asking three simple questions:

1. Ask the person to smile. Does one side of the face droop?
2. Ask the person to raise both arms. Does one arm drift downward?
3. Ask the person to repeat a simple sentence such as “It is sunny out today.” Are the words slurred? Can the patient repeat the sentence correctly?

If the person has trouble with any of these tasks, call 9-1-1 immediately and describe the symptoms to the dispatcher.

Researchers found that people who are not medically trained can use these three questions to correctly identify facial weakness, arm weakness, and speech problems. The American Stoke Association is promoting the dissemination of this knowledge to as many people as possible. If more people know what to do if someone may have had or is having a stroke, more lives can be saved.

Case study

A mass e-mail message that has been widely circulated recently describes a case in which a woman stumbled and fell at a backyard barbecue. According to the author of the e-mail who was close friends with the hosts of the party, the woman who had fallen assured everyone that she was fine and said she had tripped over a brick because of her new shoes. Her friends cleaned her up and prepared a new plate of food for her. According to accounts from the party, she appeared a bit shaken up, but proceeded to enjoy herself the rest of the evening. In the wee hours of the morning, her husband called a close relative of the e-mail author to say that his wife had been taken to the hospital. Later in the day, she died.

The woman had suffered a stroke at the party. The intent of the e-mail was to tell readers that if someone at the party had known to ask her the three questions listed above, the stroke victim may still be with us.

Resources

Many organizations, some national and others local, focus on stroke awareness and helping stroke victims and their friends and family. Visit these sites to learn more about strokes, mini-strokes, risk factors, statistics, and treatments.

American Stroke Association (www.strokeassociation.org)

National Stroke Association (www.stroke.org)

Stroke Awareness (www.strokeawareness.org)

Stroke Awareness Foundation (www.strokeinfo.org)

Stroke Awareness of Everyone, SAFE (www.strokesafe.org)

Information contained in this article was provided through the Safety & Health Committee of the National Stone, Sand & Gravel Association.

Like most workers in the mining industry, drivers of ready-mix trucks are often in harm’s way as they fulfill their responsibilities during a normal workday. They drive large trucks on company property and possibly public routes – facing all the hazards of the road. They are exposed to wet concrete, which can burn and dry the skin; and they put together, take apart, and work around discharge chutes, the long troughs that transport ready-mix from the mixer to the job site. Chutes can be tricky.

Accidents related to the handling of delivery chutes on concrete mixers are responsible for many of the lost workdays of ready-mix operators. The risk factors include the design of the supports of the various components of the chute apparatus, the position of the supports and controls, the layout of the rear of the mixer, the state of the systems, and work practices. The most hazardous work for the operator related to chutes involves deploying and stowing them.

Earlier this year, a ready-mix driver at an aggregates operation was seriously injured when setting up his chutes. His was the first truck on the job, and he was simultaneously talking to the contractor as he prepared his truck to pour. He put his gloves on and started to connect the chutes. As he was getting ready to attach the third chute, he reached for the bottom with his left hand to pull it into the hooks. At the same time, he let go of the chute with his right hand, pinching his fingers squarely between the second and third chutes.

After six hours in the emergency room, where he was in extreme pain, he was allowed to go home. He was scheduled to return for surgery the next week. The doctor said he thought the driver had saved his finger from being severed by wearing heavy leather gloves.

Safety precautions highlighted by this incident include the following:

• Always grab, hold, and carry the chutes from the sides, never the ends. Make it a habit!
• Pull the chute into the hooks when holding onto the sides of the chute. Keep one hand high to keep it from flopping over onto the chute above.
• Wear good leather gloves when working with chutes.

After this accident, the safety manager at this facility added more emphasis on this task to operator training. He also committed to altering the training trucks by painting the ends of chutes red to highlight this danger in hopes that new drivers will develop correct and safe habits from the start.

Another mixer driver’s finger recently was harmed when, as he was lowering a discharge drop chute, his finger was caught between the safety catch handle and the safety bar. The drop chute safety catch had been incorrectly fitted. The manufacturer had not supplied fitting instructions with the catch. The cut was serious and required stitches.

This incident highlights the necessity of ensuring that each truck’s chutes and safety mechanisms are properly fitted. A safety catch should be positioned to give clearance of 150 millimeters between the pivoting chute and the fixed chute.

Lessons to be learned in this case include the following:

• If instructions for properly fitting the drop chute’s safety catch are not provided by the manufacturer, ask for them.
• Ensure that the safety catch is inspected regularly. With use, wear and tear, distortion, and incorrect fitting may reduce the clearance between the fixed and pivoting chutes. If the clearance measures at less than 75 millimeters, repair or replace the safety catch.
• Wear good leather gloves when working with chutes.

Information contained in this article was provided through the Safety & Health Committee of the National Stone, Sand & Gravel Association.

Hard hats are bulky, hot, tight, and uncomfortable, and often are just one more thing to remember when you are rushing to work. Some miners may try to rationalize not wearing appropriate headgear by pointing to its limitations – if a blow is strong enough, a hard hat may not help. Statistics indicate, however, that hard hats do protect workers from many injuries and save lives.

A Bureau of Labor Statistics survey of accidents and injuries unveils that most workers who sustain head injuries do not wear head protection. Most are injured while performing their normal jobs at their regular work sites, where they are not required by their employers to wear hard hats.

The mining industry encompasses work of all types that involves risks of head injuries. The Mine Safety and Health Administration (MSHA) requires hard hats for these work categories. Headgear is intended to provide limited protection from impact and penetration from falling objects. It should be constructed in a way to be effective in preventing injury from small falling objects – whether tools or rocks. It also should be designed to provide impact protection for the sides of the head and from electrical shock hazards. Even minor head injuries can cause loss of brain function and lead to comas, disabilities, and even death.

The modern hard hat

Workers in the construction industry began wearing hard hats almost 80 years ago, around World War I. The first “Hard-Boiled Hat,” patented in the United States in 1919 by E. D. Bullard Co., was made of steamed layers of glued canvas that were then hardboiled and painted black. Not long after developing the hard shell, Bullard also developed an internal suspension system for added protection and hard hat history unfolds.

Canvas hats were replaced by aluminum ones in 1939 for all but electrical work, and, in the 1940s, fiberglass hats became the rage. They were easier to manufacture as well as lighter in weight and more protective. In the 1950s, thermoplastics were discovered as a suitable material for hard hats. They were even easier to mold and shape. Today, most hard hats are made from high-density polyethylene (HDPE), but some workers, especially those who buy their own equipment, prefer brown fiberglass hard hats, which balance well on the head and are resistant to scrapes and stains. Other characteristics of the modern hard hat include the following:

• It has a rigid shell to deflect blows to the head;
• It has a suspension system inside that spreads the helmet’s weight over the top of the head acting like a shock absorber, cushioning the blow;
• It may serve as an insulator against electric shocks;
• It shields scalp, face, neck, and shoulders against splashes, spills, and drips; and
• It may be fitted with a visor, ear protector, mirror, light, and chin strap for additional protection.

Safety requirements

Under government regulations (30 CFR56/57.15002), employers – who are responsible for managing workplace health and safety – must require that workers wear hard hats when their work involves certain hazards, including the following:

• Being struck on the head by a falling object;
• Striking against fixed or protruding objects; and
• Being exposed to electrical conductors.

Hard hats must meet the American National Standards Institute (ANSI) standard Z89.1-1986 for vertical impact and penetration. An appropriate hart hat should protect a head from injury from small falling objects. The shell, or outside of a hard hat, should be rounded to protect the crown of the head. If worn properly, the shell – in conjunction with the suspension inside the hat – will reduce the impact of the blow to the head.

In 1997, ANSI published a revision to its Z89.1 protective standard that has not yet been adopted officially as part of Occupational Safety and Health Administration regulations, but most manufacturers already comply with it:

• Type I hats are designed to reduce the force of impact from a vertical blow to the top of the head.
• Type II hats are intended to provide protection against both vertical and lateral impact and penetration requirements. It has an additional foam inner lining made of expanded polystyrene (EPS). Safety managers will determine which jobs and areas of the work site require Type II protection.
• Hard hats are also made to protect workers from electrical currents and checked for combustibility and flammability.

Hard hats are available in different colors, which can be used to signify workers’ roles: for example, white for supervisors, blue for technical advisors, red for safety inspectors, and yellow for workmen.

Care for your hard hat

Employers are also responsible for training workers on when and where to wear hats and on how to care for them to preserve their protective qualities.

Last summer, MSHA issued a Program Information Bulletin (P07-16) about hard hats because officials had become alarmed by the practice of cutting apart and re-gluing the shells of hard hats among workers in the industry who wanted to make their hats more stylish and comfortable. The PIB insists that hard hats should not be modified in this drastic way. It states that mine operators must ensure that hard hats are not modified and that they are properly maintained.

The PIB warns miners that these modified hats are unlikely to provide the level of protection promised by the manufacturers. This extensive structural modification reduces the hat’s performance capability and puts workers in greater danger of injury. “Miners must wear suitable hard hats and maintain them in accordance with the manufacturer’s instructions,” it reiterates.

Training should include a review of the following general guidelines for maintaining safe hard hats:

• Inspect your hard hat before and after each use.
• If your hat is involved in an impact accident, replace it immediately.
• If your hat is dropped from an elevation of 20 feet or more, replace it.
• If you wear your hard hat every day in a harsh environment and sunlight, such as a quarry or yard, replace it after two years. Factory, warehouse, and office workers hats may be effective for three years. When your hat is new, write the two-year replacement date clearly inside the hat with a marker. Inspect your entire team’s dates at routine training meetings to keep everyone aware of the importance of staying on schedule with replacements.
• Replace interior suspension webbing every year. Sweat, hair lotion, and sunscreen can contaminate it and accelerate wear.
• Clean your hat with mild soap and warm water. Let it air dry.
• Never use solvents or a cleaner on your hat.
• Never store your hat where it will be exposed to direct sunlight or to extreme hot or cold temperatures – for example, avoid leaving your hat in the window of your car or pickup where it is exposed to direct sunlight and heat.
• Don’t place stickers within 1/2 inch of brim and don’t cover up cracks or other damage. Although stickers are okay as an expression of corporate identity or a worker’s individual personality, beware that they could have a metal component that could act as a conductor and cause electric shock.
• Don’t drill holes in hard hats to apply nametags. This will weaken the ability of the helmet to absorb a blow.
• Check for a good fit, especially with the suspension on the nape of neck. The brow cap should fit snuggly on the forehead.
• Follow the manufacturer’s instructions for sizing the hat correctly for your head.

Information contained in this article was provided through the Safety & Health Committee of the National Stone, Sand & Gravel Association.

Highwalls jut across the landscape. The soaring
height of rock is breathtaking. The tall quarry walls are beautiful,
showing off faults and folds of shale and rock bands. The series of
layers, benches cut in the rock, resemble tiers on a cake, towering many
stories, sometimes more than 100 feet in height. They are especially
beautiful to those who make their living from mining operations, but
they are also potentially treacherous, particularly to those who work
close to them every day.

Very serious and sometimes fatal injuries occur
when heavy material — rock — falls, rolls, or slides from highwalls.
Workers at the crest — or the top — of a highwall may fall as the top of
the face drops, while workers down the wall and in the pit may be hit
and crushed. The rate of accidents and fatalities demonstrates the
necessity for ongoing safety training.

The Department of Labor and the Mine Safety and
Health Administration (MSHA) define a highwall “as the unexcavated face
of exposed overburden and material on an open face or bank” and are
conscientious about educating mining operators and workers about the
potential dangers of working close to it.

The term the government uses for managing the
physical aspects of surface mining is “ground control.” Ground control
encompasses the management of highwalls and other potential danger areas
that result from sand and gravel and crushed stone operations. The
government outlines basic job steps, describes potential hazards and
accidents, and recommends safe job procedures in Ground Control, module
11 of its Sand, Gravel, and Crushed Stone On-the-Job Training Modules.

MSHA also produced a short video called Highwall
Hazard Recognition, which is available on the Internet’s You Tube Web
site (www.youtube.com/watch?v=HFZZF7Khksc). A scene plays out between a
seasoned miner and a new miner traveling by haul truck to work in a
quarry after a heavy rain. When they encounter a boulder in the middle
of the road, they wonder where it came from. They call their boss who
comes to the spot and sees that the rock fell from the face of the highwall and the area will need to be scaled to make it safer. The rain
may have exacerbated a plane of weakness — a joint, fault, fracture,
bedding plate, mud sink, or blasting damage — loosening the large rock
and enabling it to fall. Other rocks may have been loosened, too. The
workers were praised for noticing the rock and making a call.

In an open pit with highwalls, the first step
toward achieving safety goals is to begin with a sound engineering
design that helps ensure the stability of the highwall. To maintain safe
control of the face as mining proceeds, the overall slope must be
established and followed by operators. The engineering design, whether
simply a gradual slope or a series of benches of particular widths and
angles, should consider carefully the nature of the ground and the type
of material mined. However, unknown structural weaknesses — the planes
of weakness mentioned above — are hidden in rock, and miners should use
continuous care when mining along the wall and scaling (cleaning the
face of loose rock).

Once a safe plan for mining and controlling the
wall has been developed and communicated, the supervisor should follow
basic safety guidelines for any mining site and specific guidelines
related to safe work on a highwall. For example, good housekeeping is
essential at all mine sites; clutter at a highwall site exacerbates
problems if rocks begin to slide.

Everyone at a site should participate in routine
highwall safety instruction, including sharing tips for working at the
top as well as on the bottom of a highwall. Safety belts and lines
should be worn by workers who are working within 6 feet of a crest or
unstable ground; hard hats should be worn by all workers.

A supervisor or other competent person must examine
the working area and the working faces for unsafe conditions at the
beginning of each shift and after blasting. Highwall banks, benches, and
terrain sloping into the work areas should be examined after each rain,
freeze, or thaw before work begins in the area. Overhanging highwalls
should be taken down and other unsafe ground conditions corrected or
warning signs posted.

Miners must inspect their working place before
starting work and be aware of any changes in conditions. Any unsafe
condition must be reported and corrected. Cracks, cavities, and other
unstable areas should be identified, marked, and avoided.

Heavy equipment can cause rock falls if driven on
unstable ground at the crest of a highwall or along a bench.

Miners should avoid working between mobile
equipment and the highwall, where escape routes may be blocked if a
rockslide begins.

To avoid accidents, MSHA recommends the following
best practices:

• Examine and monitor highwall often.

• Follow ground control plan.

• Train miners to recognize hazardous highwall conditions.

• Scale down or support the hazardous highwall areas.

• Keep drill and other mobile equipment
  operators away from highwall face or highwall hazards by positioning
  them in safe locations.

• Employ mining methods that will maintain wall,
  bank, and slope stability in places where persons work or travel.

Information contained in this
article was provided through the Safety & Health Committee of the
National Stone, Sand & Gravel Association.

 

Each year, welding and cutting operations yield many of the reported accidents at aggregate mines. Potential health and safety hazards result from sparks, hot metal and radiant energy, and the fumes and gases produced during this work. Equipment may generate high voltages or use compressed gas, and thus, require special awareness and training.

To safeguard workers, pay attention to the following items.

• Slag: Injuries caused by burns during welding and cutting operations result when slag, the hot metal byproduct of the processes, lands on workers. Ears are primary targets, but unprotected skin in other body areas such as between sleeves and gloves and between pants and boots can also be hurt when they come in contact with hot surfaces or hot loose metal. Slag may fly, fall, drip, or ooze as work is executed.

• Intense heat: Unexpected and irregular flash or arc burns can hurt exposed skin. The harm and pain from these burns usually worsens throughout time.

• Intense light: Bright flashes of ultraviolet light cannot only burn skin, but also the lens of the eye. Damage may occur instantly or gradually throughout time if protective eyewear is not worn and if it is not appropriate for the intensity of the light.

• Inadequate preparation: If metal objects being welded or cut have not been properly aligned and secured before work begins, they may slip, cutting or pinching workers as they try to make adjustments as they work.

• Harmful fumes: Burning metal and metal-bearing materials, especially those containing lead or cadmium, may release highly toxic chemicals into the air. Employers must check that ventilation is adequate in work areas before any welding or cutting begins. Mechanical ventilation or individual respirators will work in an area that may be in a confined space cut off from natural ventilation.

• Electric shock: Any electric welder can cause electrocution if the electrode touches exposed skin while the worker is grounded. Shock can cause involuntary muscular contractions and even death.

Best practices

Employers are responsible for providing a safe work environment and educating workers on safe work procedures. This means that workers must receive basic training for the job at hand and be informed of all safety and health hazards involved. Equipment must be inspected regularly to ensure that it is adequately maintained and safe to operate. Workers must be required to wear appropriate personal protective equipment, and the work area must be safe. Fire extinguishers must be handy, and the area must be properly ventilated.

Wearing the right personal protective equipment is the most important precaution for workers who are welding and cutting. Clothing should be made of heavier cloth such as wool or heavy cotton. Welder’s jackets provide excellent protection for the upper body. Sleeves should be unrolled and collars should be buttoned. Shirts should not have front pockets so that sparks cannot lodge in these areas and cause burns. Pants should not have cuffs or be turned up for same reason, and frayed clothes, which are susceptible to catching fire and burning, should not be worn. Workers should wear appropriate flame-resistant gloves, aprons, shields, or leggings, leather capes, and sleeves, as necessary. They should also use helmets with filter lenses to protect them from arc rays as well as sparks and spatter. Spectacles with side shields or goggles will protect against slag chips, grinding fragments, wire wheel bristles, and similar hazards.

Information contained in this article was provided through the MSHA-NSSGA Alliance and was written cooperatively by members of both the aggregates industry and the regulatory agency.