Many older floor materials contained asbestos as a strengthener. It was used in a similar way that glass fibers are used in Fiberglass but unfortunately we have later found that asbestos can cause serious health problems.
For remodelers there seems to be no field test that we can use to findout if the tile we are removing has Asbestos in it so regulations usualy assume that all flooring that could contain it should be handled in a way as asbestos made products.
Friable or NonFriable
This is the term given to whether or not the asbestos in the materials can endup airborn Friable means it can. For the most part if the Tile is in place and in decent condition it is not a problem. But when you start to disturb it like trying to remove it that can cause a problem.
Mechanical means for removal is best done with hand tools and not heavy chippers or blasting tools which will break up the tile.
When removing the tile if it comes off in full pieces and does not crumble then you are in a pretty safe condition but you still need to take precautions.
If you have any concerns as to the removal process or the condition of your floor you should hire a licensed professional to perform the work for you.
There is no good reason to take chances when your health maybe at risk.