Which condition would disqualify a cylinder from passing inspection?

The correct answer emphasizes the critical importance of maintaining the structural integrity of a fire extinguisher cylinder. Corrosion that has removed more than 10 percent of the cylinder's wall thickness is a serious concern because such degradation can compromise the cylinder's ability to withstand the high pressures involved in storage and discharge of the extinguishing agent. This level of corrosion indicates that the cylinder may be at risk of failure, which poses a significant safety hazard during operation.

Fire extinguishers must reliably function in emergencies, and any condition that could lead to a breach of the cylinder could result in dangerous situations for users. Thus, cylinders showing such significant corrosion are deemed disqualified from passing inspection to ensure the safety and reliability of fire safety equipment.

On the other hand, minor cosmetic damage, visible label damage, and normal wear and tear generally do not impact the functional integrity of the cylinder itself. While these conditions should still be addressed, they do not necessarily indicate an immediate risk for cylinder failure like severe corrosion does. This focus on structural integrity underscores the critical safety standards required for fire extinguishing equipment.