chapter 79 Zinc and articles thereof
Subheading Note.
1.- In this Chapter the following expressions have the meanings hereby assigned to them:
(a) Zinc, not alloyed
Metal containing by weight at least 97.5 % of zinc.
(b) Zinc alloys
Metallic substances in which zinc predominates by weight over each of the other elements, provided that the total content by weight of such other elements exceeds 2.5 %.
(c) Zinc dust
Dust obtained by condensation of zinc vapour, consisting of spherical particles which are finer than zinc powders. At least 80 % by weight of the particles pass through a sieve with 63 micrometres (microns) mesh. It must contain at least 85 % by weight of metallic zinc.