The following gases shall be accepted as propellants, as constituents of propellants, or as filler gases, for aerosol dispensers (1950 aerosols): gases of items 1 A, 1 O and 1 F, other than 2203 silane; gases of items 2 A and 2 F, other than methylsilane assigned to identification No 3161; and 1070 nitrous oxide of item 2 O.