The use of C2H5CL

Ethyl chloride is an inexpensive ethylating agent. Chloroethane is used to convert cellulose to ethylcellulose, a thickening agent and binder in paints, cosmetics, and similar products.

Like other chlorinated hydrocarbons, chloroethane has been used as a refrigerant, an aerosol spray propellant, an anesthetic, and a blowing agent for foam packaging. 

It acts as a mild topical anesthetic by its chilling effect when sprayed on skin, such as when removing splinters or incising abscesses in a clinical setting.

in dentistry, chloroethane is used as one of the means of diagnosing a 'dead tooth', i.e. one in which the pulp has died. A small amount of the substance is placed on the suspect tooth using a cotton wad. Chloroethane's low boiling point creates a localised chilling effect.