# HTS 9902.01.32: Entirely spherical silicon dioxide micro-spheres, certified by the importer as having mean particle size of 3 to 18 micrometers (µm), linseed oil absorption 150 to 400 ml/g, microbial count less than 100 cfu/g, mold count less than 100 cfu/g, heavy metals less than 20 ppm, surface area 300 to 800 m²/g and pore volume of 0.8 to 2.5 ml/g (CAS No. 7631-86-9) (provided for in subheading 2811.22.10)

> Plain-language tariff reference from the USITC Harmonized Tariff Schedule on [PlainTariff](https://plaintariff.com/).

## Duty rates

- **General (MFN) rate:** Free
- **Special / FTA rate:** No change
- **Column 2 rate:** No change
- **Corpus rank:** #4476 of 5979 among duty-free tariff lines

## Classification path

- **Section XXII:** [Special Classification Provisions](https://plaintariff.com/section/xxii-special-classification-provisions)
- **HTS code:** 9902.01.32

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*Source: U.S. International Trade Commission Harmonized Tariff Schedule. HTML canonical: https://plaintariff.com/heading/99020132-entirely-spherical-silicon-dioxide-micro-spheres-certified*