Which NDE method(s) may cause problems in a confined space by displacing breathing air?

The correct choice highlights the potential hazards associated with certain non-destructive examination (NDE) methods in confined spaces, focusing specifically on Magnetic Particle Testing (MT) and Liquid Penetrant Testing (PT). These two methods involve the use of chemicals and can produce fumes or vapors that might displace breathable air, leading to a decrease in the oxygen levels available for workers in confined areas.

In the case of MT, the magnetic particles and the magnetic field needed during testing may not be harmful on their own, but the liquid media used in the process can evaporate and displace air. Similarly, PT uses penetrating fluids that can release vapors, which may create additional risks in an environment with limited ventilation.

Other methods like Ultrasonic Testing (UT) and Radiographic Testing (RT), while they also have their safety considerations, do not typically displace breathing air in the same manner as MT or PT. Visual inspection is a low-risk method that does not involve chemicals or processes that could affect air quality. Radiographic Testing and Eddy Current Testing (ET) likewise involve other types of environmental controls and precautions without causing the same direct issue with air displacement.

This distinction emphasizes the unique safety concerns that MT and PT introduce in confined space inspections