If you have an old home, then you may find that some of your pipes have asbestos insulation installed. There is so much old lagging that can be wrapped around pipes, particularly in the crawlspace, or in the attic, that you may be unsure whether any of it is actually dangerous, or if it is just some rotten old tape around fabric. The only way to find out is to check.
You may have some types of insulation that you already suspect, but if not, and your home fits into the years when asbestos was installed, then check for loose insulation, particularly a grayish fabric which is slightly fluffy. It may look like the lining of a duffel coat, for example. It is usually flecked with slightly different colors of fabric.
Checking the Pipes
Pipes are the most common victims of asbestos insulation, so check for blanket-style fittings around the curves and joints of your pipes. Insulation can look rather like cardboard coverings, so if you are unsure, it is best to remove everything and start again. You may be unwilling to purchase the microscopy that is the only method of proving what is asbestos, so treat it all as though it were, and take it out.