The arrivals corridor is deemed as non-sterile as it mixes arrivals from both EU and non-EU points. Hence, once you set foot in the arrivals corridor you are considered contaminated and must be re-screened prior to re-entry into the RZ.

Sealed cans unfortunately will not be permitted through security checkpoints as one cannot verify the contents of the can without opening it. It may be labelled as Haggis but it may contain deadly water for all they know. This is really annoying for Gatwick staff that work airside as it somewhat restricts the meals you can bring to work.