The safest way to remove chips from a lathe or milling machine is to use a:

The safest way to remove chips from a lathe or milling machine involves using a brush. A brush is designed to gently sweep away chips and debris without risking injury to the operator or damaging the equipment. It allows for a controlled manner of cleaning where the operator can keep their hands away from moving parts, thereby reducing the chances of accidents.

Using a vacuum can also be effective, but it might not provide the same level of control when dealing with larger chips. The vacuum may inadvertently suck up tools or parts that are still in place, potentially causing issues. A metal scraper could be dangerous if it slips or if the operator loses control, as it involves direct contact with the machinery. Similarly, using a hand tool for chip removal may pose risks since it can lead to accidental engagement with moving components.

Overall, a brush provides an appropriate balance of safety and effectiveness, making it the preferred choice for chip removal in this context.