Radiopaque plastics: which additive is commonly incorporated to make a plastic impervious/opaque to X-rays?

Introduction / Context:
Medical devices, cable jackets, and non-destructive testing markers often require radiopacity. Adding high-atomic-number fillers to polymer matrices increases X-ray attenuation, enabling visibility under imaging.

Given Data / Assumptions:

• Barium salts (e.g., barium sulfate) are widely used radiopaque fillers.
• Asbestos is not used for safety reasons; phthalic acid is a plasticiser intermediate; SiC is abrasive, not radiopaque.

Concept / Approach:
X-ray attenuation increases with atomic number and density. Barium (Z=56) salts dispersed in plastics create radiopaque composites suitable for medical tubing and markers without severely compromising processability.

Step-by-Step Solution:
Identify heavy element additive: barium salt.Eliminate asbestos (hazard), SiC (not radiopaque), phthalic acid (not a filler).

Verification / Alternative check:
Material datasheets list BaSO4-filled PVC/PU as standard for radiopaque products.

Why Other Options Are Wrong:
They do not confer X-ray opacity or are unsuitable.

Common Pitfalls:
Confusing UV opacity with X-ray opacity; mechanisms differ.

Final Answer:
Barium salt