Date of incident: October 2024
Notice of incident number: 2024167090038
Employer: Environmental services company

Incident summary
At an organics processing facility and turf farm, a worker was operating a loader while a horizontal grinder (a large machine used to grind wood and other organics) was being operated nearby. The grinder ejected a projectile, which flew toward the loader. It broke through the loader’s windscreen and struck the loader operator, who sustained serious injuries.

Investigation conclusions

Cause

• Grinder struck foreign material and hammer tip dislodged. The grinder mill contains multiple hammers and hammer tips to grind various materials. While the loader operator was operating the loader in front of the grinder, the grinder mill struck foreign material, and a 3 kg (7 lb.) hammer tip dislodged. The forged steel tip flew approximately 27.4 m (90 ft.) toward the loader and broke through the loader’s windscreen.

Contributing factors

• Manufacturer’s instructions not adhered to. The horizontal grinder involved in the incident was not being maintained in accordance with the manufacturer’s instructions. Over time, slight movement in the bolts on the hammer tips due to under-torquing and fretting wear could have gradually worn the bolts and created a vulnerable point in the assembly, potentially contributing to bolts coming loose. In addition, the manual recommended that a minimum 152.4 m (500 ft.) safe zone be established in front of the machine. This was not done, and at the time of the incident, the loader operator was working in what should have been the designated safe zone.
• Inadequate training and safe work procedures. Workers were given on-the-job training but did not have access to written safe work procedures for their work tasks. The employer did not provide any documentation of training or orientation for the workers at the organics processing facility and turf farm.
• Inadequate supervision. The employer did not ensure that a safe zone, away from workers and equipment, was in place and maintained before the incident. In addition, it did not ensure that workers had safe work procedures, which could have guided them to perform more frequent inspections and use correct techniques for torquing the bolts on the hammer tips.

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