Delegated exemption notification cannot redefine tariff classifications for plastic goods; trade meaning prevails and exemption stands.

A delegated exemption notification could not supply an exhaustive definition of "rigid" and "flexible" plastic articles where the tariff item itself used those terms without definition. The court treated classification for duty purposes as a legislative function and held that the notification could not create a fresh classification scheme or displace the trade, commercial and ordinary meaning earlier applied to the tariff entry. Because the notification went beyond the scope of the delegated power and altered the scope of exemption, it was invalid and the petitioners were entitled to exemption.

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Issues: Whether the Central Government, by an exemption notification issued under the excise rules, could define the expressions "rigid" and "flexible" so as to determine the class of plastic articles eligible for exemption under the tariff item.

Analysis: The notification did not merely regulate the conditions of exemption but supplied an exhaustive norm for classifying plastic articles as "rigid" or "flexible". The earlier judicial understanding had treated those expressions according to their trade, commercial, and ordinary meaning because the tariff item itself contained no such definition. A delegated exemption notification could not be used to create a fresh classification scheme or to alter the scope of the tariff entry, since classification of goods for duty purposes is a legislative function.

Conclusion: The notification was beyond the scope of the delegated power and could not validly displace the trade meaning previously applied. The challenge succeeded and the petitioners were entitled to exemption.

Ratio Decidendi: An exemption notification under delegated power cannot introduce a substantive classification of excisable goods where the tariff entry does not itself define the relevant terms, particularly when the effect is to alter the scope of exemption.

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