Toxicity of aerosol propellants in the respiratory and circularoty systems. X. Proposed classification.

The 15 propellants are grouped into four classes on the basis of results of investigation reported in this series of publications. Class 1 low-pressure propellants of high toxicity; Class 2 low-pressure propellants of intermediate toxicity; Class 3 high-pressure propellants of intermediate toxicity; and Class 4 high-pressure propellants of low toxicity.