What is one of the first signs that cleaning efforts have failed?

The indication that cleaning efforts have failed is often reflected in an initial visual inspection showing residue. When residues remain visible, it suggests that contaminants have not been fully removed during the cleaning process. This is particularly relevant in trauma and crime scene scenarios, where it is essential to ensure that all biological and chemical contaminants are eliminated for safety and health reasons.

In contrast, a negative test result doesn't necessarily mean cleaning was successful; it might reflect limitations of the testing method or timing. Adequate ventilation is important for minimizing exposure to airborne contaminants but does not directly indicate the effectiveness of the cleaning process. Reports of fewer incidents may suggest a change in conditions or environment but do not provide evidence about the thoroughness of the cleaning efforts in a specific area. Thus, residue visible after the initial inspection serves as a clear and immediate sign of ineffective cleaning practices.