Chlorine scrubber is a device for removing contaminants from a gas stream by passing the stream up through a liquid spray or liquid flow. The contaminant, in this case chlorine, is removed from the gas as it is dissolved into the liquid. The chlorine scrubbing system, or scrubber, represents existing technology for controlling accidental or routine releases of chlorine gas. A scrubber is basically a process equipment unit that collects chlorine vapor and mixes it with alkaline solution (caustic) to remove the chlorine. The main reaction product is hypochlorite. The most common chemical used for scrubbing is sodium hydroxide (caustic soda), although others such as sodium carbonate and calcium hydroxide may be used. Scrubbers are often associated with neutralizing accidental releases, but they are also used for neutralizing routine process releases. Proper sizing and design of the scrubbers are important. Significant heat is generated by the caustic-chlorine reaction, so materials must be chosen for heat and chemical resistance as well as for strength. Scrubber's designs include venturi systems, horizontal sprayers & packed media and usually recirculation caustic solutions.