Ammonia is classified as which refrigerant category?

• A. A1
• B. B2
• C. C1
• D. B1

Answer: (B)

Refrigerants are classified by two characteristics: how toxic they are and how flammable they are. Ammonia is known for being toxic to humans; exposure can be harmful and requires careful handling. It is not considered flammable under normal conditions, so it does not fit the flammable category.

Putting those together, ammonia belongs in the toxic, non-flammable group. The other labels would imply either non-toxicity, or flammability that ammonia does not exhibit in typical operating conditions, so they aren’t appropriate for ammonia.