the safest utility knife has what type of blade? self - retracting folding replaceable plastic

Brief Explanations:

A self - retracting blade on a utility knife is designed to automatically retract when not in use. This feature significantly reduces the risk of accidental cuts as the blade is not exposed unnecessarily. Folding blades may still pose a risk if not folded properly. Replaceable blades do not inherently add to safety in terms of preventing accidental exposure. Plastic blades are often less sharp and may not be as effective for many utility knife tasks, and their safety in terms of preventing accidental cuts due to exposure is not as reliable as the self - retracting mechanism.

Answer:

self - retracting