Why can CFC or HCFC refrigerants leaking into a confined space or in limited surroundings cause suffocation?

Correct Answer: Option A — Refrigerants are heavier than air and displace oxygen.

Halocarbon refrigerants (CFCs and HCFCs) are significantly heavier than air. When leaked into confined engineering spaces or shipboard compartments, they pool near the deck plates, displacing breathable oxygen and creating an extreme asphyxiation and suffocation hazard.