Papain , its cas register number is 9001-73-4. It also can be called Velardon ; and Vermizym . Its classification code are Drug / Therapeutic Agent; Enzyme [proteolytic]; Human Data; Natural Product; Reproductive Effect and TSCA Flag XU [Exempt from reporting under the Inventory Update Rule]. Papain (CAS NO.9001-73-4) could be stable at room temperature in closed containers under normal storage and handling conditions. It should avoid the condition like incompatible materials, dust generation, excess heat, strong oxidants. It is not compatible with strong oxidizing oxidizers. And also prevent it to broken down into hazardous decomposition products: carbon monoxide in cases of incomplete combustion, carbon dioxide. However, its hazardous polymerization will not occur. I'd like to know something about its usage, can anyone tell me ? thank you very much.