OxidantsAlso known as oxidizing agent, oxidizer or oxidiser, is the element or compound in an oxidation-reduction (redox) reaction that accepts an electron from another species. Because the oxidizing agent is gaining electrons (and is thus often called an electron acceptor), it is said to have been reduced.
OzoneA colourless gas, a highly reactive compound in which each molecule consists of three oxygen atoms. Ozone is "good up high, bad nearby": In the stratosphere, it forms a protective layer against UV light. But at ground level it is increasingly harmful to breathe as concentrations rise and contributes to or aggravates various heart and lung conditions, such as asthma and it also interferes with the ability of plants (including crops) to produce and store food. Ozone is a criteria pollutant and is the prime ingredient of summertime smog in most cities. Ozone is not emitted directly into the air, but is formed in reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of heat and sunlight.
Ozone depleting substancesOzone depleting substances (ODSs) are those substances which deplete the ozone layer and are widely used in refrigerators, air conditioners, fire extinguishers, in dry cleaning, as solvents for cleaning, electronic equipment and as agricultural fumigants. Ex: Chlorofluorocarbons (CFCs), Halon, Carbon tetrachloride (CCl4), Methyl chloroform (CH3CCl3), Methyl bromide (CH3Br) etc.
Ozone holeThinning break in the stratospheric ozone layer. Designation of “ozone hole” is made when detected amount of depletion exceeds fifty percent. Seasonal ozone holes have been observed over both the Antarctica and the Arctic region and part of Canada and the extreme North-eastern United States.
Ozone Layer (Ozonosphere)A layer of ozone in the lower portion of the stratosphere, 12 to 15 miles above the Earth's surface, which helps to filter out harmful ultraviolet rays from the sun.