I would warn against a dog in the shop when doing hot work such as welding or cutting. An old friend of mine told of a dog that had gone blind watching a welding arc.
While working under a vehicle we have been nose to mustache (she was checking for food scraps) but she has never licked my face even though my legs and hands are fair game. I believe dogs understand and know a lot more than we think they do. Have a good day
Ray