Under ASHRAE Standard 34, which safety group is R-123 assigned to?

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

ASHRAE Standard 15 equipment-room requirements and refrigerant sensors.

The question

Under ASHRAE Standard 34, which safety group is R-123 assigned to?

• AA1
• BA2L
• CB1Correct answer
• DB2L

Why “B1” is correct

R-123 is classed B1: "B" for higher toxicity and "1" for no flame propagation. Its higher toxicity is why EPA's test topics single out a refrigerant sensor for R-123 equipment rooms; current editions of ASHRAE Standard 15 require one for every refrigerant.

Source: ASHRAE Standard 34; Hudson Technologies R-123 P-T chart (ASHRAE 34 rating); EPA: Test Topics

Why the other answers are wrong

• A1 — A1 is the lower-toxicity, non-flammable group of refrigerants such as R-11 and R-134a.
• A2L — A2L is for lower-toxicity, mildly flammable refrigerants.
• B2L — B2L is for higher-toxicity, mildly flammable refrigerants such as ammonia.

Practice more of this

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