The chemicals in Thames and Kosmos kits are packed in a child-proof chemical vials. The multilingual labels display the hazard symbols and warnings for the substance contained inside each vial. The illustration shows how to use the enclosed lid opener to open the safety closure. When you open the vial, some of the chemical substance might fall onto your hand or the work surface. You can avoid that by tapping the vial several times on the work surface before opening it. After removing what you need, immediately close the vial again. Some chemicals come in larger vials, with a safety closure that can be opened by pushing and turning at the same time. It takes some effort to open and close the safety closures. If necessary, have an adult help you.