1.   This ejected fine dust and ash particles into the atmosphere, which are believed to be accelerating the chemical reactions by which ozone is destroyed by chlorine compounds.

2.   At high altitudes, Freons are broken down by ultraviolet radiation from the sun, producing chlorine compounds that react with ozone.

3.   Some people object to adding chlorine compounds to their pool water because they feel it causes eye irritation and it gives off an unpleasant odor.

4.   The manufacture and production of the harmful chlorine compounds is being phased out under an international agreement called the Montreal Protocol.

5.   This initiates a chain reaction, in which the destructive chlorine compounds are regenerated, becoming available to destroy still more ozone.

6.   Chlorine compounds used in refrigerants, aerosol sprays and solvents are blamed for most ozone depletion.

7.   Human-made chlorine compounds used in refrigerants, aerosol sprays, solvents, foam-blowing agents and bromine compounds used in firefighting halogens cause most ozone depletion.

8.   This could have come from a chlorine compound, according to a gas company official inspecting the site.

9.   Wood said scientists expected ozone holes will develop each spring in Antarctica for several decades because of the chlorine compounds from CFCs already released into the atmosphere.