These plates are used for Thin Layer Chromatography (TLC) and can be made from glass, aluminum foil, or plastic. The plates themselves are cut and shaped by the manufacturer and are as durable as the material they're made from. To allow for the TLC process to take place, the plates are coated with an adsorbent material, such as silica gel or aluminum oxide. These coatings are usually thin, hard-powder substances. As the name suggests, TLC plates are essential for use in chromatography, which is the process of separating chemical mixtures into their purest forms. Applications of TLC include identifying the purity of a solution, measuring a reaction, and identifying compounds. The different coatings will aid in various ways to ensure proper results every time. While the plates themselves are highly stable and do not pose any physical threat, the adsorbent coatings can be toxic if ingested and will be irritating to the skin if touched directly. Depending on the treatment used and the concentration of it on the plate, some adsorbents can pose a greater risk than others. TLC plates should be stored in cool, dry areas and individually wrapped to ensure that the coating does not come off. As for the plates, they do not pose any significant environmental impact. The coating, however, may be toxic to wildlife and should be disposed of according to state and federal regulations.