Tin was a chemical element and a metal.
A popular form of confectioner's Easter egg was made of chocolate and wrapped in coloured tin foil. The Tenth Doctor ate part of one of these before giving the remainder to Christina de Souza, concerned sugar might damage his teeth. (TV: Planet of the Dead)
The Tenth Doctor described the launch of Apollo 11 as "packing three men into a tin can filled with a skyscraper's worth of fuel, hurling them out of the atmosphere into the harshest conditions imaginable, with nothing more powerful than a pocket calculator to guide them. For what? Just because you can." (PROSE: Blue Moon)