CFR › Title 27 › Part 21 › §21.12227 CFR §21.122Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy link(a)Color. White or yellow.(b)Specific gravity at 20 °C. 1.95 to 2.10.(c)Melting point. 360 °C.(d)Boiling point. 1320 °C.(e)pH (0.1M solution). 13.5.