In the 19th and 20th centuries, asbestos was used in many building materials to prevent fire from spreading throughout a building. In the 1980s, restrictions started being placed on the use of asbestos. By the '90s, no new tiles were made with it.
If you are remodeling a home or office with ceiling tiles that were installed before the early 1990s, they might contain asbestos. There will usually not be any kind of indication on the tiles themselves. The only way to know for sure whether your ceiling tiles have asbestos is to have them tested by a certified asbestos-testing lab.