1. Methods of test for orthoboric acid (boric acid), diboron trioxide (boric oxide), disodium tetraborates, sodium perborates and crude sodium borates for industrial use. Determination of bulk density of sodium perborates Part 21, (28th February 1979) Authors: British Standards Institution, Record Type: Book Extent: 1 online resource (8 pages) View Content: Available online (eLD content is only available in our Reading Rooms) ↗