A deposit or emulsion at the interface between two partially settled phases.
- The phenomenon of crud formation arises from many causes and this definition does not imply any single one.
- Other terms -- some unprintable -- have been used but crud is the generally accepted term.
PAC, 1993, 65, 2373. 'Nomenclature for liquid-liquid distribution (solvent extraction) (IUPAC Recommendations 1993)' on page 2387 (https://doi.org/10.1351/pac199365112373)