On 19 December 1994, the United Nations (UN) General Assembly proclaimed 16 September every year to be observed as the International Day for the Preservation of the Ozone Layer to commemorate the same date in 1987, on which the Montreal Protocol on Ozone Depleting Substances - ODS was signed. ODS are widely used in refrigerators, air-conditioners, fire extinguishers, in dry cleaning, as solvents for cleaning, electronic equipment and as agricultural fumigants.
Some of the ODS are ChloroFluoroCarbons (CFCs), Halon, Carbon Tetrachloride, Methyl Chloroform, Methyl Bromide, HydroBromoFluoroCarbons (HBFCs), HydroChloroFluoroCarbons (HCFCs), BromoChloroMethane (BCM). The Ozone Depleting Potential - ODP of a compound "x" is defined as the ratio of the total amount of ozone destroyed by a fixed amount of compound x to the amount of ozone destroyed by the same mass of CFC-11. The number and nature of the halogen has effect on ODP in the sense that bromine containing halocarbons usually have much higher ODPs than chlorine containing ones.
HCFCs are both ozone-depleting substances and powerful greenhouse gases: the most commonly used HCFC is nearly 2,000 times more potent than carbon dioxide in adding to global warming. For the 17th International Ozone Day that is being observed on September 16, 2011 the theme is “HCFC Phase-out: a unique opportunity”
Addressing the students at Way to Transform Shridhar University Pilani Rajasthan, Prof BR Natarajan Pro Vice Chancellor of the University highlighted the significance of the day in the context of the global ecosystem. He urged them to take up the challenges of developing cutting-edge technologies that not only eliminate ozone-depleting compounds but do so in a way that lowers energy costs and maximizes climate benefits.
Considering that Hydrofluorocarbons HFCs which do not deplete the ozone layer are fast replacing HCFCs, Prof Natarajan cautioned that one should not forget that HFCs are indeed highly potent greenhouse gases. Students enthusiastically participated in the proceedings sharing their opinions and resolved to do their best in this context.
For more details see http://www.shridharuniversity.ac.in
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About Shridhar University: An initiative of the Sarvhit Trust, Shridhar University Pilani has been established under Section 2(f) of UGC Act 1956 incorporated by Government of Rajasthan vide Ordinance No. 3 of 2009 and the same ratified by the Rajasthan Legislative Assembly vide Act No. 4 of 2010 as The SHRIDHAR UNIVERSITY ACT BIGODNA, JHUNJHUNU. Further, Vide letter F.No 8-3/2010(CPP-