Soda lime is generally used in anaesthesia and undersea breathing due its property of absorbing carbon dioxide. Soda lime is also used by navy in submarines, mining and petrochemical industries. The main ingredients of soda lime are Calcium hydroxide (about 75%), Water (about 20%), Sodium hydroxide (about 3%) & Potassium hydroxide (about 1%).
If soda lime is containing more than 4% sodium hydroxide then it is classified as Class 8, corrosive substances. UN number assigned to corrosive soda lime is UN 1907.
IMDG Code Compliance Centre 