Which type of refrigerant is categorized as a refrigerant with low toxicity and flammability?

R-410A is categorized as a refrigerant with low toxicity and flammability, making it a safe choice for residential and commercial air conditioning applications. It is a hydrofluorocarbon (HFC) blend that does not contribute to ozone depletion, which is a significant advantage over older refrigerants. The low toxicity of R-410A means that it poses minimal health risks to humans in case of leaks, and its minimal flammability means that it has a lower risk of igniting compared to some other refrigerants.

Ammonia, while effective as a refrigerant, has a high toxicity level and is flammable, making it less suitable for applications where safety is a primary concern. Freon, while a common term used historically, typically refers to older refrigerants like R-12, which are now phased out due to their environmental impacts. R-134A, though it has low toxicity, is less efficient than R-410A in many modern applications and does not match the performance characteristics of R-410A in terms of energy efficiency. Thus, R-410A stands out as the best option regarding low toxicity and flammability among the choices provided.