What characteristic must a solvent used to clean the surface of a test specimen NOT possess?

The characteristic that a solvent used to clean the surface of a test specimen must not possess is that it must be flammable. Using a flammable solvent can pose significant safety hazards, including the risk of fire or explosion, especially in laboratory environments where heat sources may be present. Therefore, selecting a solvent that is not flammable is critical for ensuring safety during handling and application.

In contrast, a non-toxic solvent is preferred to ensure that it does not pose health risks to individuals working with it. Quickly evaporating solvents can be beneficial for cleaning applications, as they reduce the time the solvent is in contact with the specimen and minimize the risk of contaminating the sample. Finally, solvents that leave no residue are ideal, as they ensure that any traces of the cleaning agent do not interfere with subsequent tests or analyses of the specimen. Each of these characteristics plays a vital role in the selection of a cleaning solvent, but flammability is a key concern that should be avoided to ensure safety.