Mobile Concrete Crusher Safe Work Method Statement

Concrete crushing generates massive quantities of respirable crystalline silica dust, with particles small enough to penetrate deep into lung tissue where the body cannot clear them. Dry crushing of concrete produces visible dust clouds containing silica concentrations that can exceed the workplace exposure standard of 0.05 mg/m³ by 50-100 times. Crusher operators, excavator operators feeding material, and ground personnel working downwind all experience exposure. The dust settles slowly and can remain suspended for hours after crushing ceases. Silica exposure causes silicosis, an irreversible progressive lung disease, along with increased lung cancer risk, chronic bronchitis, and immune system impairment. Unlike many hazards that provide immediate feedback, silica exposure is symptomless during exposure, with disease developing years or decades later when permanent lung scarring has already occurred.

Consequence: Silicosis causing progressive breathing difficulty and eventual respiratory failure, lung cancer with poor survival rates, chronic obstructive pulmonary disease requiring lifelong management, immune system disorders including increased susceptibility to tuberculosis, permanent disability preventing further employment in dusty environments, and premature death from respiratory complications.

Mobile concrete crushers generate extreme noise levels typically measuring 110-120 dB(A) at the crusher operator position, 105-110 dB(A) for excavator operators feeding the crusher, and 95-105 dB(A) for ground personnel within 20 metres. This far exceeds the 85 dB(A) exposure threshold requiring hearing protection. The noise comprises both continuous components from diesel engines, conveyor systems, and screening equipment, plus impact noise from concrete chunks striking crusher chambers and hammers. Exposure to these levels causes immediate temporary hearing threshold shifts, and regular exposure without adequate protection causes permanent noise-induced hearing loss. The damage is cumulative and irreversible, affecting ability to understand speech, hear warning signals, and maintain quality of life. Crusher operators wearing inadequate hearing protection can experience measurable permanent hearing loss after weeks or months of daily exposure.

Consequence: Permanent noise-induced hearing loss starting with high-frequency sounds and progressing to affect speech frequencies, tinnitus causing constant ringing or buzzing in ears affecting sleep and concentration, difficulty understanding speech in noisy environments or with background noise, social isolation from communication difficulties, inability to hear warning signals creating safety risks, and reduced employability in roles requiring good hearing.

Excavators continuously maneuver around crushers to load material, creating constant struck-by risk for ground personnel. Excavator operators focus attention on bucket positioning and crusher feed rate rather than watching for ground personnel. The confined site area means workers often position themselves near operating excavators to remove contamination, clear stockpiles, or guide truck movements. Excavator rear visibility is extremely limited, making reversing movements particularly hazardous. The noise from crushers prevents verbal warnings being heard. Excavator slew movements create wide strike zones where the counterweight can contact personnel positioned behind the machine. Site congestion increases when delivery trucks arrive to collect finished product, adding another mobile plant interaction hazard.

Consequence: Fatal crush injuries from being struck by excavator bodies or counterweights, severe traumatic injuries including skull fractures and internal injuries from bucket impacts, limb fractures and amputations from being caught between excavator and fixed objects, spinal injuries causing permanent paralysis, and multiple trauma requiring extended hospitalization and rehabilitation.

Crusher internal mechanisms including rotating hammers, conveyor belts, screening decks, and feed augers present extreme entanglement and crushing hazards. Workers may approach or enter crusher mechanisms to clear blockages when oversize material jams the feed system, adjust conveyor belt alignment, or inspect wear components. The crushing chamber contains rotating hammers or reciprocating jaws with sufficient force to instantly crush concrete blocks, and would cause fatal injuries if contacted by any body part. Inadequate isolation during maintenance allows accidental startup crushing workers inside equipment. Bypassed or removed safety guards allow access to dangerous moving parts during operation. Loose clothing, gloves, or tools can be caught by moving components dragging workers into machinery. Production pressure to clear jams quickly encourages risky practices including reaching into machinery without proper isolation.

Consequence: Fatal injuries from being drawn into crushing chambers or caught in conveyor systems, severe traumatic amputations of hands, arms, or legs caught in moving machinery, crushing injuries to body or head causing permanent disability or death, degloving injuries where skin is torn from underlying tissue, and psychological trauma for workers witnessing machinery entanglement incidents.

Prolonged crushing operations without adequate cleaning allow accumulation of fine concrete dust within crusher housings, screening decks, and conveyor enclosures. When disturbed or suspended in air in sufficient concentrations, this dust can ignite from sparks or hot surfaces creating dust explosions. While less common than in grain handling or coal processing, concrete dust contains combustible components including gypsum and organic additives that can support combustion. Metal-on-metal contact between wear parts and reinforcement steel, overheated bearings, or welding activities during maintenance can provide ignition sources. The confined spaces within crusher housings can intensify explosion pressure waves. Regular inspection and cleaning reduces accumulated dust, but many crushing operations defer housekeeping until equipment malfunctions.

Consequence: Explosion injuries including burns, blast injuries to lungs and internal organs, eye injuries from pressure waves and projectiles, equipment damage requiring extensive repairs and operational downtime, fire spread to adjacent equipment and stockpiled materials, and potential for secondary explosions if initial blast suspends additional settled dust.

Mobile crushers require regular maintenance including replacement of wear liners in crushing chambers (typically weighing 30-80kg each), changing screening decks to modify product sizes (mesh panels weighing 20-40kg), and replacing conveyor belts and pulleys. These components must be manually handled in confined spaces within crusher frames, often at awkward heights requiring reaching, lifting overhead, or working in cramped positions. Liner removal requires impacting with sledgehammers to break free seized components, creating jarring forces through workers' shoulders and backs. Screen deck access typically requires climbing into equipment and positioning bodies in twisted or bent postures to reach fixing bolts. The frequency of maintenance, typically required weekly for high-use crushers, means workers face repeated manual handling exposures causing cumulative damage.

Consequence: Chronic lower back pain and disc injuries from repetitive heavy lifting in awkward postures, shoulder injuries including rotator cuff damage from overhead work and hammer impacts, hand and wrist injuries from maintaining grip on heavy components in confined spaces, knee damage from kneeling on metal surfaces during maintenance work, and gradual development of osteoarthritis in affected joints reducing long-term mobility and function.