... :28151100 3. Purity: 96%, 99%, etc 4. Appearance: Flakes, Pearl (white or light blue) Caustic sodaCas no.: 1310-73-2 properties ... 0.0040.0060.0080.010.02Standard of identity of flaky caustic soda flakes: name of specification\ grademembrance processdiaphragrn processNaOH %≥9996.0Na2CO3 ... -2 2. HS Code:28151100 3. Purity: 96%, 99%, etc 4. Appearance: Flakes, Pearl (white or light blue) Caustic Soda 99%