Refrigerant classification

Refrigerant classification

The ISO 817 and ANSI / ASHRAE 34 standards are safety classifications for refrigerants.

The toxicity rating is divided into two groups, Low Toxicity A and Low Toxicity B.

The flammability of a refrigerant is divided into four categories according to these standards, with Class 1 being virtually incombustible under most conditions of use. R 410A and R 22 both in Class 1 are considered virtually non-combustible.

Class 2L (L = low) is considered to be low flammability, classified as having low combustion rate and having lower heat of combustion. Class 2 and Class 3 designate flammable and highly flammable refrigerants. R 152a is a class 2 refrigerant, while the hydrocarbons (propane, butane) are classified as highly flammable class 3 refrigerants. 

ISO 817 Refrigerant Classification Scheme