... . CAS NO.:1310-73-2 2. HS Code:28151100 3. Purity: 96%, 99%, etc 4. Appearance: Flakes ... , Pearl (white or light blue) Caustic sodaCas no.: 1310-73-2 ... 010.02Standard of identity of flaky caustic soda flakes: name of specification\ grademembrance ... 2 2. HS Code:28151100 3. Purity: 96%, 99%, etc 4. Appearance: Flakes, Pearl (white or light blue) Caustic Soda 99 ...