This specification establishes requirements for chemically blown cellular rubber. Cellular rubber may be classified into two types: Type I which is open cell or sponge rubber and Type II which is closed cell or expanded rubber. Both types are divided into three grades: Grade A which is oil-and flame-resistant, Grade B which has no requirements for oil ,flame resistance, or low temperature, and Grade C which is low-temperature resistant. Each type and class has been divided into three different conditions. Each condition is based on a specific range of firmness as expressed by compression deflection as follows: super soft, soft, soft-medium, medium, medium-firm, and firm conditions. Several tests shall be performed in order to determine the following physical properties of cellular rubber: compression deflection, low-temperature resistance, accelerated aging, recovery, flame resistance, shrinkage, water absorption, oil aging, and color.