Azodicarbonamide (AC or ADCA) is the most popular chemical blowing agent. Generally, AC is orange to pale yellow, crystalline solid with a decomposition temperature of 201~205°C (in air). Unlike a number of other chemical blowing agents, AC is self-extinguishing when flame is removed. The decomposition residues are odorless, non-toxic, non-coloring and non-straining. The particle size and distribution can be controlled with widely different ranges. The particle size and distribution is one of the most significant factors.