Identify one major safety consideration when operating a CNC milling machine.

One major safety consideration when operating a CNC milling machine is to always wear appropriate personal protective equipment (PPE), including safety glasses. This is crucial because CNC milling involves the use of sharp tools and high-speed rotation, which can produce flying chips, debris, and other hazards that pose a risk to the operator's eyes. Safety glasses provide a barrier against such dangers, helping to prevent serious eye injuries.

Proper PPE encompasses more than just safety glasses—it also includes items like hearing protection, protective clothing, and steel-toed boots, all of which contribute to a safer working environment. While wearing gloves might seem beneficial, they can actually pose risks when working with rotating machinery, as they could get caught in moving parts. Using noise-canceling headphones is not a direct safety consideration related to the operation itself, even though it helps reduce exposure to hazardous noise levels. Lastly, ensuring the machine is well oiled is essential for maintenance and operation efficiency but does not directly address personal protection during use.