The classification of cellulose acetate flakes (also known as diacetate flakes) in the Harmonized Commodity Description and Coding System (HS code) primarily depends on their specific form, intended use, and level of processing.

According to China Import and Export Tariff and Harmonized Commodity Description and Coding System:

The most accurate code is: 3912.1100

39.12: Cellulose and its chemical derivatives in primary forms.

3912.11: - Cellulose acetate in primary forms.

3912.1100: -- Cellulose diacetate.

Classification basis and explanation:

1. Chemical nature: Tobacco cellulose diacetate flake is a chemical product in primary shape formed after acetylation reaction, precipitation, washing, and drying. It has not been spun into tow, nor has it been made into filter rods. Therefore, it belongs to primary shape; chemical raw materials.

2. Excluding other chapters:

It does not belong to the products in the latter half of Chapter 39 (such as films classified under 3920-3921), as it requires subsequent deep processing steps such as dissolution and spinning.

It also does not belong to tobacco products (Chapter 24) because it does not contain tobacco itself and is purely a chemical raw material.

3. Industry practice: In import and export trade, the raw material chips imported by factories producing acetate tow are usually declared under item 3912.1100.