If your tiles are older than 1980,or smaller than 12 by 12 they may be Asbestos containing. If the tiles do not contain Asbestos thenselves, the mastic may! It should be checked also. Depending on your state requirements, Asbestos abatement(fancy word for removal and cleanup) may be against the law unless you are a licensed and trained contractor. I strongly suggest to do the due dilligence on this issue. If after all that due dilligence you find out it it not Asbestos, get really well aquainted to: gloves, safety glasses kneepads sharpened prybar hammer and aspirin. This removal is usually a thankless job! Good Luck!