Scaling highwalls presents several hazards that need careful assessment and control. Here's a breakdown of potential risks and mitigation strategies:

Hazards:

1. Dust Exposure: Cutting, grinding, or disturbing materials like structural panels 1, 2, 6, 10, 14, 17, ceiling tiles 3, 12, 15, 18, 19, or wall textures 4, 5, 9 can generate dust containing hazardous substances such as crystalline silica 1, 2, 4, 5, 6, 10, 17, gypsum 15, 18, 20, limestone 3, 4, 5, 8, 9, mica 4, 5, 9, cellulose 11, 15, 16, 20, starch 3, 5, 9, 11, 16, 20, continuous filament glass fiber 1, 2, 6, 7, 10, 17, and portland cement 1, 2, 6, 7, 10, 17. Inhalation of these dusts can lead to respiratory irritation, coughing 7, 10, 12, 17, 18, and long-term health issues like silicosis or other lung diseases 7, 10, 17, 18.
2. Eye and Skin Irritation: Direct contact with dust can cause irritation to the eyes and skin 7, 10, 12, 17, 18.
3. Falls from Height: Working on highwalls inherently involves the risk of falls, which can result in serious injuries or fatalities.
4. Falling Objects: Loose debris or equipment can fall from the highwall, posing a risk to workers below.
5. Unstable Highwall: The highwall itself may be unstable, leading to collapses or slides.
6. Equipment Hazards: Machinery used for scaling, such as excavators or specialized scaling tools, can cause injuries if not operated correctly or maintained properly.

Risk Assessment:

• Likelihood: The likelihood of dust exposure, eye/skin irritation, and falling objects is high if controls are not in place. The likelihood of falls from height and highwall collapse depends on the stability of the highwall and the safety measures implemented.
• Severity: The severity of these hazards ranges from minor irritation to serious injuries, long-term health effects, or death.

Control Measures:

1. Elimination/Substitution: Where possible, eliminate the need for scaling by using alternative methods such as remote-controlled equipment or designing slopes that do not require scaling.
2. Engineering Controls:
   • Ventilation: Use local exhaust ventilation to capture dust at the source 4, 13.
   • Dust Suppression: Apply water sprays or other dust suppression techniques to minimize airborne dust 4, 13.
   • Highwall Stabilization: Implement measures to stabilize the highwall, such as slope reinforcement or terracing.
3. Administrative Controls:
   • Training: Provide comprehensive training on scaling techniques, hazard identification, and the use of safety equipment.
   • Safe Work Procedures: Develop and enforce safe work procedures, including pre-shift inspections of the highwall and equipment.
   • Spotters: Use spotters to monitor the highwall for signs of instability and to warn workers of potential hazards.
   • Work Scheduling: Schedule work to minimize exposure to extreme weather conditions.
4. Personal Protective Equipment (PPE):
   • Respiratory Protection: Provide and ensure the use of NIOSH-approved respirators for dust exposure 1, 5, 6, 9, 16, 19, 20. Consult with a respirator manufacturer to determine proper selection, use and limitations 1, 5, 6, 9, 16, 19.
   • Eye Protection: Wear approved safety goggles to protect against dust and debris 1, 2, 4, 5, 6, 9, 16, 19, 20.
   • Skin Protection: Wear long-sleeved shirts, pants, and gloves to minimize skin contact with dust and materials 1, 5, 6, 16, 19, 20.
   • Fall Protection: Use appropriate fall protection equipment, such as harnesses and lanyards, when working at heights.
   • Head Protection: Wear hard hats to protect against falling objects.

Monitoring and Review:

• Regularly monitor air quality to ensure dust levels are within acceptable limits 4, 5, 6, 9, 16, 19, 20.
• Conduct routine inspections of the highwall and equipment.
• Review safety procedures and update them as necessary.
• Investigate all incidents and near misses to identify and correct any deficiencies in the safety program.

By implementing these control measures and maintaining a strong safety culture, the risks associated with scaling highwalls can be significantly reduced.