The only way to be positive that your tiles contain asbestos is to have a sample tested by an accredited laboratory. The Occupational Safety and Health Administration recommends treating all resilient flooring installed before 1980 as if it contains asbestos.
While there is a good chance that 9-inch and 12-inch tiles manufactured before 1980 contain asbestos, the hazardous fiber is also found in larger- and smaller-dimension tiles. Even the adhesive used to install the flooring, especially if it’s black “cutback” adhesive, could contain asbestos. The same concerns apply to vinyl and other sheet-type flooring and attached fiber backing. According to the EPA, taking a sample for testing is not a do-it-yourself project. A professional familiar with asbestos should remove the sample and seal the removal area.