CFR › Title 21 › Part 82 › §82.133421 CFR §82.1334Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkCalcium salt of 3-hydroxy-4-[(1-sulfo-2 -naphthalenyl)azol-2-naphthalenecarboxylic acid.