Chlorine (Cl):

Chlorine is a chemical element with symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidizing agent: among the elements, it has the highest electron affinity and the third-highest electronegativity, behind only oxygen and fluorine.

The most common compound of chlorine, sodium chloride (common salt), has been known since ancient times. Around 1630, chlorine gas was first synthesized in a chemical reaction, but not recognized as a fundamentally important substance. Carl Wilhelm Scheele wrote a description of chlorine gas in 1774, supposing it to be an oxide of a new element. In 1809, chemists suggested that the gas might be a pure element, and this was confirmed by Sir Humphry Davy in 1810, who named it from Ancient Greek: χλωρός, translit. khlôros, lit. ‘pale green’ based on its color.

Because of its great reactivity, all chlorine in the Earth’s crust is in the form of ionic chloride compounds, which includes table salt. It is the second-most abundant halogen (after fluorine) and the twenty-first-most abundant chemical element in Earth’s crust. These crustal deposits are nevertheless dwarfed by the huge reserves of chloride in seawater.

Elemental chlorine is commercially produced from brine by electrolysis. The high oxidizing potential of elemental chlorine led to the development of commercial bleaches and disinfectants, and a reagent for many processes in the chemical industry. Chlorine is used in the manufacture of a wide range of consumer products, about two-thirds of them organic chemicals such as polyvinyl chloride, and many intermediates for the production of plastics and other end products that do not contain the element. As a common disinfectant, elemental chlorine and chlorine-generating compounds are used more directly in swimming pools to keep them clean and sanitary. Elemental chlorine at high concentrations is extremely dangerous and poisonous for all living organisms and was used in World War I as the first gaseous chemical warfare agent.

In the form of chloride ions, chlorine is necessary to all known species of life. Other types of chlorine compounds are rare in living organisms and artificially produced chlorinated organics range from inert to toxic. In the upper atmosphere, chlorine-containing organic molecules such as chlorofluorocarbons have been implicated in ozone depletion. Small quantities of elemental chlorine are generated by the oxidation of chloride to hypochlorite in neutrophils as part of the immune response against bacteria.

Interested Parties including Regulatory Authorities:

1. Persons affected by Cl
2. Industries, Laboratories using/ Generating Cl
3. Personal and commercial uses of Cl
4. Private / Govt. Projects to control Cl
5. Handling and transportation of goods containing Cl
6. Local Environmental Department/ Authorities
7. Local Government Authorities like Municipalities, City Corporations etc.
8. Local Law Enforcing Agencies like Police, Magistrate Regulatory Authorities etc.

The benefit of Monitoring:

By monitoring long-term contamination trends, every country establishes baseline contamination levels, making it possible for early identification of contamination events. Daily events and long-term trends are captured and taken step to reduce environmental emissions/ pollution and enhance the environmental performance of the society.