Catherine in Toronto has asbestos insulation on the hot water pipes that run from her boiler to her radiators. She is changing the boiler and wonders if she has to remove all the old insulation.
If the insulation is in good shape and will not be disturbed by the new work, then it can be left alone. If you want you could box it in with drywall for extra protection, but efforts to encapsulate it, like wrapping it in something should be left to a special asbestos abatement contractor. If you want to remove it, you should have a licensed asbestos contractor as well. Why so much concern about who does the work?
Loose asbestos fibers are not only a danger for the workman, but if the area around the work area gets contaminated, everyone in the house is in danger of exposure. Proper asbestos abatement contractors will be dressed like spacemen with disposable clothing and will use expensive HEPA vacuums and dispose of the clean-up as a hazardous waste. Few contractors are equipped to do that properly. Unfortunately this is not a cheap procedure and it is even difficult to find someone to do this for a small residential job.
If it is in good shape -- protect it from accidentally bumping into it and leave it be.