Provided that this section shall not apply to-
(a) any securely stoppered glass, stoneware or metal receptacle of less than [ten litres] capacity containing [petroleum Class A] [Substituted by Act 24 of 1970, for " dangerous petroleum " (w.e.f. 1.8.1976). ] which is not for sale, or
(b) a tank incorporated in a motor conveyance, or attached to an internal combustion engine, and containing petroleum intended to be used to generate motive power for the motor conveyance or engine, or
(c) a pipe-line for the transport of petroleum, or
(d) any tank which is wholly underground, or
(e) any class of receptacles which the Central Government may, by notification in the Official Gazette, exempt from the operation of this section.