What a wall-wash test checks
Wall-wash (or wall wash) testing measures residual contamination on tank surfaces after cleaning. Charterers and surveyors use it to confirm the tank is fit for the next chemical or sensitive product.
Why tanks fail
- Incomplete demucking — pockets of sludge keep contaminating rinse water
- Wrong chemistry for residue or coating
- Insufficient rinse / dead zones behind structures
- Rushed timeline that skips verification washes
Fine cleaning after demucking is the practical path to wall-wash readiness. See fine tank cleaning and our article on fine cleaning standards.
