You can tell if old flooring has asbestos if thick black flooring adhesive is underneath the tiles. However, homeowners should not cut into linoleum floors to look for this adhesive. Instead, hiring a specialist to test the floors is the only safe way to determine if old flooring has asbestos.

If you own a stereo microscope, you should be able to see the fibers. The stereo microscope often can perform magnification up to 50x. But unless you have experience viewing asbestos fibers, you may not know exactly what you are seeing. Some fibers are curly, while others are long and straight. Blue, brown, white, and gray colored fibers are all possible.

Vermiculite insulation that comes from a particular mine before 1990 is likely to contain asbestos. This is particularly true in the U.S. However, not all types of vermiculite insulation contain asbestos. Since you can't detect the presence of asbestos without special equipment, it's best to assume that the insulation contains the dangerous mineral and to either leave it alone or hire a professional to handle it.

When asbestos fibers become airborne, they enter a person's respiratory system. These fibers scar and damage the lungs and often lead to serious cancers like mesothelioma. Like many dangers in the house, asbestos isn’t easy to see when it could be causing serious damage. The amount of time exposed, combined with the person’s tolerance for asbestos inhalation and the amount inhaled, will all contribute to health problems.