Anhydrous ammonia is the favored refrigerant for big commercial and industrial systems. These need professional management anyway, and the plumbing containing

Anhydrous ammonia is the favored refrigerant for big commercial and industrial systems. These need professional management anyway, and the plumbing containing ammonia tends to be outdoors. Gaseous ammonia is buoyant, so goes up. The amount of anhydrous ammonia that would be needed to operate an RV fridge could kill you easily. Operation in an enclosed space is another source of risk.