CS –  O-chlorobenzalmalononitrile
Formula : C6H5C-OCH2Cl
Description :  Irritate eyes and nose, penetrate porous areas.
                        State: Gas or powder
                       Odor : Apple blossom pungent
                       Color :  Whitish-yellow powder
                       Type : Lachrymatory agent.
                        Persistency: Short 
                        Density: 1.318 (solid)
                        Decomposition point: 248° C
Symptoms :  Instantaneous effects, CN irritate the upper respiratory passage, 
                     powerful lachrymatory. Can irritate the skin (itching and burning 
                     sensation). High concentration causes blister and nausea.
                     Some effects are similar to sun burn and disappear in a few hours.
First aid : Wash eyes with boric acid solution and skin with warm sodium 
                     carbonate solution.