🔍 Key Concepts

• Density of common CFC/HCFC refrigerants vs. air • Behavior of gases in confined spaces • How oxygen can be displaced without being toxic itself

💭 Think About

• Think about where a heavy gas will collect if it leaks in a small, low-ventilated space. • Does a gas have to be poisonous to cause suffocation, or can it cause harm another way? • Which option describes a physical property of the gas that affects how much oxygen you can actually breathe?

✅ Before You Answer

• Check whether most CFC/HCFC refrigerants are heavier or lighter than air. • Consider which choices describe displacement of oxygen versus irritation or odor effects. • Verify which explanation matches typical confined space hazards described in safety training.