Under which condition is a refrigerant most likely to break down into toxic products?

Safety · EPA 608 Type I. The correct answer, and the reasoning behind it.

Decomposition products of refrigerants at high temperatures, and safe handling.

The question

Under which condition is a refrigerant most likely to break down into toxic products?

• AWhen it sits in a sealed cylinder at normal room temperature
• BWhen its vapor contacts an open flame or a red-hot surfaceCorrect answer
• CWhen it flows through the capillary tube
• DWhen it mixes with compressor oil

Why “When its vapor contacts an open flame or a red-hot surface” is correct

EPA's test topics list decomposition products of refrigerants at high temperatures. Refrigerants are stable in normal use, but a flame, a glowing heater element or other very hot surface can break them apart.

Source: EPA: Test Topics

Why the other answers are wrong

• When it sits in a sealed cylinder at normal room temperature — Refrigerants are stable at normal storage temperatures.
• When it flows through the capillary tube — Normal flow through a metering device does not decompose refrigerant.
• When it mixes with compressor oil — Refrigerant normally mixes with oil in every system without breaking down.

Practice more of this

More EPA 608 Type I practice questions, or see every EPA 608 practice test.