Quarries and crushing and screening plants combine many hazards: heavy mobile plant, rotating and moving equipment, work at height, explosives, dust and noise. Most serious accidents in this sector come from known, preventable risks: intervening on a running conveyor, maintenance on a crusher that has not been locked out, a truck reversing, or entering a bin. Occupational safety is not just a legal obligation but also the foundation of sustainable production.
In this guide we give an overview of the main risks in quarries and plants, the technical and organisational measures that can be taken against them, and how a safety culture can be developed. Note: This article is for general information. Every operation must carry out a risk assessment in accordance with the occupational health and safety legislation in force and work with competent professionals.
Main Risks
| Risk | Where? | Possible consequence |
|---|---|---|
| Entrapment and entanglement | Conveyor pulleys and idlers, belts and pulleys, couplings, crusher opening | Serious injury, loss of limbs, death |
| Falls | Screen platforms, bin edges, stairs, quarry benches | Serious injury |
| Vehicle traffic | Quarry roads, loading areas, stockyard | Crushing, collision, overturning |
| Blasting | Quarry | Fly rock, premature detonation |
| Slope and bench failure | Quarry face | Being buried by a collapse |
| Silica dust | Crushers, screens, transfer points | Silicosis and other occupational diseases |
| Noise and vibration | Around crushers and screens, mobile plant | Hearing loss |
| Confined spaces | Bins, silos, reclaim tunnels, chutes | Being buried by material, suffocation, oxygen deficiency |
| Electricity | Panels, cables, motors | Electric shock, fire |
| Hydraulic and pressurised systems | Crusher setting systems, mobile equipment | Injection injuries, sudden movement |
Lockout–Tagout (LOTO)
The most important cause of accidents during maintenance and breakdown work is equipment starting unexpectedly. Lockout–tagout (LOTO) is the basic procedure for preventing this risk.
- Preparation: All energy sources of the equipment are identified: electrical, hydraulic, pneumatic, gravity (suspended loads), spring energy, rotating masses (flywheels).
- Notification: Affected workers are informed.
- Stopping: The equipment is stopped by the normal method.
- Isolation: Energy sources are cut off at the isolators (switches, valves).
- Locking and tagging: Each worker fits their own personal lock to the isolator and hangs a tag. Only the lock’s owner holds the key.
- Releasing stored energy: Hydraulic pressure is relieved, accumulators drained, suspended parts supported and flywheels allowed to stop.
- Verification: Confirm the equipment will not run by trying the start button and taking measurements.
- Completing the work and returning to service: Guards are refitted, workers move away and locks are removed by their owners.
To clear crusher blockages, never intervene in the crushing chamber while the equipment is running; use only suitable hydraulic breaker equipment and safe procedures to break rock in the crusher opening.
Conveyor Safety
- Machine guards: Nip points at drive, tail, take-up and snub pulleys, belts and pulleys and couplings must be enclosed with fixed guards.
- Pull cord switches: There must be emergency stop systems running along the conveyor that stop the belt when pulled, and they must be tested regularly.
- Emergency stop buttons: Must be at accessible points.
- Start-up warning: An audible and visual warning must be given before a conveyor starts.
- Crossings: Safe bridges and walkways must be provided for crossing under or over conveyors.
- No cleaning on a running belt: Material built up around idlers and pulleys must not be cleaned with a shovel while the belt is running.
For conveyor safety equipment, see our conveyor safety equipment guide, and for conveyor maintenance, our belt conveyor guide.
Vehicle Traffic and Quarry Safety
- Traffic plan: Heavy vehicles should be kept separate from light vehicles and pedestrians as far as possible.
- Safety berms: There should be berms high enough to stop vehicles going over road and bench edges.
- Blind spots: Large trucks and loaders have blind spots; cameras, radar and reversing warning systems should be used.
- Speed limits and road maintenance: Roads should be even, watered and signposted.
- Slope control: Loose blocks should be checked when working below the quarry face, and slopes observed regularly.
- Blasting safety: The blast area must be evacuated, warning procedures followed and only authorised shotfirers allowed to work (drilling and blasting guide).
Dust and Silica Risk
Respirable crystalline silica dust produced when crushing and screening quartz-bearing rock can cause serious lung diseases such as silicosis with long-term exposure. Measures:
- Control at source: enclosing transfer points, water sprays, dust collection systems.
- Enclosed, pressurised operator cabins.
- Ambient and personal exposure measurements.
- Suitable respiratory protective equipment and training in its correct use.
- Regular health surveillance.
For technical dust control solutions, see our dust and noise control guide.
Confined Spaces: Bins, Silos and Chutes
Entering bins and silos to clear bridged or stuck material is one of the deadliest practices in the sector. Hung-up material can collapse suddenly and bury the person inside.
- Entering a bin should be avoided; designs that prevent bridging, air cannons and vibrators should be preferred (bin guide).
- If entry is unavoidable, a confined space permit, lockout, a safety harness and rescue equipment, an attendant and air monitoring must be mandatory.
- No entry should be made until feeders and conveyors have been locked out.
Noise
Noise levels are high around crushers and screens. A noise map should be produced, high-noise areas marked, hearing protection made mandatory and, where possible, noise reduced at source (rubber liners, polyurethane screen panels, enclosures).
Personal Protective Equipment (PPE)
| PPE | Use |
|---|---|
| Hard hat | The whole site |
| Steel toe-cap safety boots | The whole site |
| High-visibility vest | All areas with vehicle traffic |
| Safety glasses | Crushers, screens, cutting and welding |
| Hearing protection | Noisy areas |
| Dust mask | Dusty areas |
| Safety harness | Work at height, confined space entry |
| Work gloves | Maintenance, handling parts |
PPE is the last step in the hierarchy of risk control; the priority is always to eliminate the hazard or control it with engineering measures.
Safety in Maintenance Work
- For heavy part changes (mantle, concave, jaw plate, blow bar), suitable lifting devices and cranes should be used and a lift plan made.
- For welding and cutting, a hot work permit, fire precautions and ventilation should be provided. Fumes produced when cutting manganese steel parts require suitable respiratory protection.
- When working with chemicals such as backing compound, follow the safety data sheets.
- Never work on hydraulic systems before pressure has been relieved (hydraulic system maintenance guide).
Safety Culture
- Risk assessment: Should be updated regularly and carried out with workers’ participation.
- Training: Induction, toolbox and periodic training; especially LOTO, confined space and mobile plant training.
- Near-miss reporting: Reporting dangerous situations before an accident happens should be encouraged, and those reporting should not be penalised.
- Stop-work authority: Every worker should have the right to stop work in an unsafe situation.
- Leadership example: Managers following the rules is the strongest determinant of safety culture.
Frequently Asked Questions
What is the most common type of serious accident in crushing and screening plants?
Entrapment on conveyors and moving equipment and accidents caused by vehicle traffic are among the most serious and common.
Why is LOTO so important?
It prevents equipment starting unexpectedly during maintenance. With a personal lock, every worker controls their own safety.
Is a mask enough against silica dust?
Masks are important but not enough on their own. The priority is dust control at source, enclosed cabins and measurement.
How can bin bridging be cleared safely?
Preferably with systems that act from outside (air cannons, vibrators, design improvements). Entry should only be made under a permit, with lockout and with a rescue plan ready.
Spare Parts That Directly Affect Safety
When the maintenance of some parts is neglected, not only production but also safety is put at risk. These parts should be given priority in the maintenance plan.
| Part | Safety function | Guide |
|---|---|---|
| Conveyor pull cord switches and emergency stop buttons | Stop the belt in an emergency | Conveyor safety equipment |
| Misalignment and slip sensors | Reduce the risk of belt damage and fire | Conveyor safety equipment |
| Machine guards | Enclose nip points | Belt conveyor guide |
| Backstop | Prevents an inclined belt running back | Gearbox maintenance |
| Tension springs and rods (jaw crusher) | Breakage can cause uncontrolled part movement | Tension rods and springs |
| Hydraulic hoses and accumulators | Risk from pressurised oil and gas | Hydraulic system maintenance |
| Platforms, stairs and handrails | Prevent falls | — |
For conveyor safety equipment, guards and crusher parts, see our belt conveyor spare parts and jaw crusher spare parts pages.
Daily Safety Round Checklist
- Are all machine guards in place and sound?
- Have pull cord switches and emergency stop buttons been tested?
- Is there spilled material on platforms and walkways?
- Are start-up warning systems working?
- Are roads watered and berms in place?
- Are there loose blocks or cracks on the slopes?
- Are dust suppression systems working?
- Is PPE being used?
- Are lockout–tagout materials in place?
Glossary
- LOTO: The lockout–tagout procedure.
- Near miss: A dangerous event that was avoided before it became an accident.
- PPE: Personal protective equipment.
- Confined space: A space with restricted entry and exit and possibly inadequate ventilation (bin, silo, tunnel).
- Risk assessment: The process of identifying hazards, analysing risks and planning measures.
- Respirable crystalline silica: Quartz dust of a size that can reach the lungs.
More Questions
Is special training needed for maintenance staff?
Yes. Special training should be given in LOTO, work at height, confined spaces, heavy lifting, hot work and hydraulic systems.
What should happen to conveyor guards during maintenance?
Guards should only be removed after the equipment has been locked out, and refitted at the end of the job before the equipment is started.
Do the same rules apply to contractors?
Yes. All contractors working on site should be included in the operation’s safety rules and permit system.
Support from CSP Mühendislik
CSP Mühendislik integrates safety equipment such as safe access platforms, machine guards, pull cord switches and misalignment sensors into plant design, and provides suitable equipment and service, maintenance and repair support for safe maintenance. For conveyor safety equipment and other parts, see our belt conveyor spare parts page. For plant design, see our crushing and screening plant set-up guide.
