DAS (4,4'-Diamino-2,2'-stilbenedisulfonic acid) Technical Grade
Technical grade DAS is a high-purity form of 4,4'-diamino-2,2'-stilbenedisulfonic acid used in optical brightener production. It falls under HTS 2921.59.2000 due to its precise chemical identity as a chemically defined aromatic polyamine per Chapter 29 note (a). Impurities are minimal and do not alter its classification.
Import Duty Rates by Country of Origin
| Origin Country | MFN Rate | Ch.99 Surcharges | Total Effective Rate |
|---|---|---|---|
| 🇨🇳China | 6.5% | +35.0% | 41.5% |
| 🇲🇽Mexico | 6.5% | +10.0% | 16.5% |
| 🇨🇦Canada | 6.5% | +10.0% | 16.5% |
| 🇩🇪Germany | 6.5% | +10.0% | 16.5% |
| 🇯🇵Japan | 6.5% | +10.0% | 16.5% |
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If mixed with solvents or additives for specific industrial formulations
Chemical preparations not chemically defined fall under Chapter 38 mixtures.
If processed into synthetic organic fluorescent brightening agent
Brightening agents derived from this compound are classified in 3204 per Chapter exclusions.
If sulfonic acid groups dominate over amine functions
Sulfonated derivatives may shift to earlier headings under numerical order rule.
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Import Tips & Compliance
• Request supplier specs showing >95% purity to distinguish from 'other' polyamines in 2921.59.8000
• Declare exact CAS number (128-71-2) on entry documents for customs verification
• Check for stabilizer additions; per Chapter notes, these don't change classification if for safety/transport
Related Products under HTS 2921.59.20.00
4,4'-Diamino-2,2'-stilbenedisulfonic acid
This is a specific aromatic polyamine derivative with two amino groups and sulfonic acid groups, classified under HTS 2921.59.2000 as it exactly matches the chemical structure of 4,4'-diamino-2,2'-stilbenedisulfonic acid. It serves as a key intermediate in dye synthesis, particularly for direct dyes used in textile coloring.
4,4'-Diaminostilbene-2,2'-disulfonic acid Powder
Powdered form of 4,4'-diamino-2,2'-stilbenedisulfonic acid, a white to light yellow crystalline compound used as a dye precursor. Classified specifically under HTS 2921.59.2000 as a separate chemically defined organic compound per Chapter 29 scope. The powder form with anti-caking agent is allowed under note (f).