CHLORINE

PRODUCT IDENTIFICATION

H.S. CODE

CLASSIFICATION

PHYSICAL AND CHEMICAL PROPERTIES

Greenish yellow gas with a pungent, irritating odor

-101 C

AUTOIGNITION

NFPA RATINGS

REFRACTIVE INDEX

GENERAL DESCRIPTION & APPLICATIONS

Chlorine is a toxic, corrosive, greenish yellow gas with a pungent, irritating odor. Chlorine belongs to the halogen family of elements, found in group VIIa of the periodic table. Chlorine is produced mostly by electrolysis of brine; some is obtained as a by-product in the manufacture of sodium metal by the electrolysis of sodium chloride either molten or in solution. Chlorine is soluble in water. Its aqueous solution ( called chlorine water) consists of a mixture of chlorine, hydrochloric acid, and hypochlorous acid; only a part of the chlorine introduced actually goes into solution, the major part reacting chemically with the water. Chlorine water has strong oxidizing properties resulting from the oxygen set free when the unstable hypochlorous acid decomposes. Chlorine combines directly with almost all the elements except the rare gases, excluding xenon, and nitrogen. Besides the -1 oxidation state of the chlorides, chlorine also exhibits oxidation state respectively : +1 (hypochlorite, ClO^- ), +3 (chlorite, ClO^-₂), +5 (chlorate, ClO^-₃ ) and +7 (perchlorate, ClO^-₄). Very reactive and unstable four oxide compounds have been indirectly synthesized; chlorine monoxide (Cl₂O), chlorine dioxide (ClO₂), dichlorine hexoxide (Cl₂O₆), and dichlorine heptoxide (Cl₂O₇). Uncombined chlorine does not occur in nature due to its activity, but its compounds are numerous. Chlorine can displace the heavier halogens, bromine and iodine, from their ionic compounds and undergoes addition or substitution reactions with organic compounds. Chlorine is used in water purification; as a disinfectant and as an antiseptic (mercuric chloride). Chlorine is a general biocide substance killing germs, micro-organisms, algae, etc. The most widely used chloride chemical disinfectants are chlorine, ozone, chlorine dioxide and chloramine.

Chloramine is an ammonium containing chlorine disinfectant. Monochloramine, dichloramine and trichloramine are in equilibrium when produced by the chemical chloramination of ammonia. Monochloramine is the only effective ammonia-chloramine disinfectant. Dichloramine (NHCl2) and nitrogen trichloride (NCl3) are too unstable to be useful and highly malodorous. Production conditions are practically employed for the production of monochloramine by lowering the pH and adjusting the molar ratios of the reactants. Chloramine is a toxic yellow liquid at room temperature. Due to high CT values, chloramine is a poor primary disinfectant but is an attractive secondary disinfectant for the maintenance of a stable distribution system residual and eliminating the formation of chlorination by-products. Chloramine is one of the most widely used chemical disinfectants in drinking water system. Chloramine-B and Chloramine-T are antiseptic agents derived from combining chloramine and benzenesulfonamide (or p-toluenesulfonamide) repectively. Sulfonamide molecular structure is similar to p-Aminobenzoic acid (PABA) which is needed in bacteria organisms as a substrate of the enzyme dihydropteroate synthetase for the synthesis of tetrahydrofolic acid (THF). Sulfonamides are capable of interfering with the metabolic processes in bacteria that require PABA. They act as antimicrobial agents by inhibiting bacterial growth and activity. Chloramine B and Chloramine B are used as an oxidizing agent, an antiseptic, a germicide as well as a chlorinating agent in organic synthesis. Its ions resulting from dissolving in water involve in interfering with micro-organisms' cell process by oxidations of proteins or enzyms.

Hypochlorite is an alternative choline source when chlorine gas is impractical. The commercially available liquid hypochlorite form is sodium hypochlorite (NaOCl) which is used as the disinfectant in hospitals. But this is highly caustic, ethanol class disinfection has replaced. Sodium hypochlorite have also been used extensively in the disinfection of drinking-water. Hypochlorite anion,ClO^-, changes the oxidation-reduction potential of the cell, and resulting in the inactivations of the micro-organism's function. Chlorine is used to bleach fabrics, woodpulp and paper, to clean dairy equipment, to control biofouling in cooling systems, to shrink-proof wool, and to detin and dezinc iron. Chlorine are used directly or as an intermediate for the synthesis of many organic chemicals; pesticides, antifreeze, refrigerants, antiknock compounds, synthetic rubber and plastics, chlorinated hydrocarbons, polyvinyl chloride, ethylene dichloride hypochlorous acid, chlorobenzene, chlorinated lime, carbon tetrachloride, ethylene and propylene oxides, glycols, trichloroethylene, perchloroethylene, chloroform, vinylidene chloride, polychloroproprene, hydrogen chloride, metal chlorides, chloracetic acid, chloral, synthetic glycerine, methyl chlorides, chlorinated benzenes, tetraethyl lead, fluorine compounds, titanium tetrachloride, monochloroacetic acid, phosgene, chloroisocyanuric acid, phosphorus chloride dichlorobutene, and chlorinated paraffins.

APPEARANCE

Greenish yellow gas with a pungent, irritating odor

WATER

50ppm max

NONVOLATILE RESIDUE

30ppm max

TRIHALOMETHANES

100ppm max

100ppm max

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