A produce chamber (1) is provided to subject produce in a crate (7) to a controlled atmosphere. The chamber (1) has at least one inflatable/deflatable balloon seal structure (15) for sealingly engaging with a side wall of a produce crate (7) which has at least one opening (13) in a side wall (11) thereof. The balloon seal structure (15) has at least one discharge opening (19) that aligns with the at least one crate opening (13). Crates (7) with produce therein can be loaded in the chamber (1) with the balloon seal structure (15) deflated. The balloon seal structure (15) can then be inflated and controlled atmosphere allowed to circulate through the balloon seal structure (15) and discharged from the opening (19) and through the crate opening (13) to expose the produce to a controlled atmosphere.