Rubber processing chemical classification turns on predominant common use, so BHT fell under the residuary tariff item.

Tariff Item 65 applied only to accelerators and antioxidants used as rubber processing chemicals; the decisive test was whether the substance's predominant or common use was as an antioxidant in rubber processing, not merely whether it was chemically an antioxidant. On the facts recorded, BHT was not shown to have that predominant or common use, so it did not fall within Item 65. In the absence of a more specific entry, the residuary Item 68 governed classification.

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Issues: Whether BHT (Di-butyl Para Crosol / Butylated Hydroxy Toluene) was classifiable under Tariff Item 65 as a rubber processing chemical, or under the residuary Item 68.

Analysis: Tariff Item 65 covered accelerators and antioxidants only when they were rubber processing chemicals. The decisive test was not merely whether the substance was an antioxidant, but whether its predominant or common use was as an antioxidant in the processing of rubber. On the facts found, the predominant or common use of BHT was not such use. Since no specific entry otherwise applied, the residuary item governed.

Conclusion: BHT was held to fall outside Tariff Item 65 and within residuary Item 68.

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