What is the most severe injury related to abrasive grinding wheels?

• A. Wheel explosion
• B. Hearing loss
• C. Electrical shock
• D. Skin burns

Answer: (A)

The danger being tested is how dangerous a grinding wheel can be if it fails. A wheel in a grinder stores a lot of energy while it’s spinning. If the wheel cracks, is mounted incorrectly, or is run at a speed or under a condition it wasn’t designed for, it can break apart and explode. When that happens, fast-moving fragments are hurled in multiple directions and can cause catastrophic injuries—penetrating wounds to the eyes, face, or body, severe lacerations, or even fatalities. That’s why guards are required and why wheel inspection, proper mounting, correct speed, and using the right wheel for the job are emphasized so that the energy stored in the wheel doesn’t become a projectile.

Hearing loss, electrical shock, and skin burns are real hazards from grinding operations, but they don’t typically have the sudden, high-energy, multi-directional injury potential of a wheel explosion. Preventing wheel explosions relies on careful maintenance and safe operation: inspecting wheels for cracks, mounting with the correct flanges, using wheels within their rated speed, keeping guards in place, and wearing appropriate eye/face protection and other PPE.