Division 1 Within any one heading of this chapter, polymers (including copolymers) and chemically modified polymers are to be classified according to the following provisions:

1. (a)

   where there is a subheading named ‘Other’in the same series:

   1. (1)

      the designation in a subheading of a polymer by the prefix ‘poly’(for example, polyethylene and polyamide-6,6) means that the constituent monomer unit or monomer units of the named polymer taken together must contribute 95 % or more by weight of the total polymer content;

   2. (2)

      the copolymers named in subheadings 3901 30, 3901 40, 3903 20, 3903 30 and 3904 30 are to be classified in those subheadings, provided that the comonomer units of the named copolymers contribute 95 % or more by weight of the total polymer content;

   3. (3)

      chemically modified polymers are to be classified in the subheading named ‘Other’, provided that the chemically modified polymers are not more specifically covered by another subheading;

   4. (4)

      polymers not meeting (1), (2) or (3) above, are to be classified in the subheading, among the remaining subheadings in the series, covering polymers of that monomer unit which predominates by weight over every other single comonomer unit. For this purpose, constituent monomer units of polymers falling in the same subheading shall be taken together. Only the constituent comonomer units of the polymers in the series of subheadings under consideration are to be compared;

2. (b)

   where there is no subheading named ‘Other’in the same series:

   1. (1)

      polymers are to be classified in the subheading covering polymers of that monomer unit which predominates by weight over every other single comonomer unit. For this purpose, constituent monomer units of polymers falling in the same subheading shall be taken together. Only the constituent comonomer units of the polymers in the series under consideration are to be compared;

   2. (2)

      chemically modified polymers are to be classified in the subheading appropriate to the unmodified polymer.

Polymer blends are to be classified in the same subheading as polymers of the same monomer units in the same proportions.