No change No change On or before 12/31/2020 . 32. Certain spherical particles of silicon dioxide Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.01.31 Amorphous silicon dioxide micro-spheres of mean particle size 0.003-0.018 mm, linseed oil absorption 30-40 ml/g, surface area less than 80 m²/g, and pore volume less than 0.1 ml/g (CAS No. 7631–86–9) (provided for in subheading 2811.22.10) Free No change No change On or before 12/31/2020 . 33. Certain spherical particles of silicon dioxide Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 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) Free No change No change On or before 12/31/2020 . 34. Thionyl chloride Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.01.33 Thionyl chloride (CAS No. 7719–09–7) (provided for in subheading 2812.17.00) Free No change No change On or before 12/31/2020 . 35. Green chrome oxide Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.01.34 Chromium(III) oxide (CAS No. 1308–38–9) (provided for in subheading 2819.90.00) Free No change No change On or before 12/31/2020 . 36. Oxoiron Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.01.35 Iron(III) oxide (Pigment red 101) (CAS No. 1309–37–1) (provided for in subheading 2821.10.00) 2.5% No change No change On or before 12/31/2020 . 37. Hydroxylamine free base Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.01.36