12.1 Vapours displaced from the tank during loading,
tank cleaning, tank breathing and gas-freeing should be emitted through
a controlled tank venting system complying with either SOLAS regulation II-2/16.3.2, or paragraph 8.3.2 of the IBC Code, or paragraph 2.14.2
of the BCH Code, as applicable.
12.2 Whenever a vapour emission control system
is available ashore, vapours displaced from the tank during loading
should be returned to that system (vapour return).