1. OZONE and the ENVIRONMENT

2. Just what is Ozone?
Ozone is a form of oxygen with a different chemical property
Ozone differs from oxygen:
Has a distinctive odor
Contains 3 oxygen atoms
Absorbs damaging ultraviolet (UV) radiation
In large concentrations ozone is hazardous

3. Earth’s Atmosphere
Troposphere start on the surface and extends 5 – 9 miles
Air most dense
All weather occurs is this region
Stratosphere extends for 31 miles
Contains the Ozone layer

4. Composition of the Atmosphere
Nitrogen 78%
Oxygen 21%
Argon 1%
Water Vapor 0 – 7%
Ozone 0.01%
Carbon Dioxide 0.01 – 0.1%

5. Ozone’s Primary Function
Block or absorb most of the suns ultraviolet rays
Approx. 3,000 million tons of ozone in atmosphere
If concentrated at sea level, would measure only 3 mm thick
Depletion of this protective shield allows too much UV radiation to strike earth

6. Measuring the Ozone Layer
In 1920 Gordon Dobson began researching the ozone layer and its effects
Dobson Unit – Measures intensity of light passing through ozone layer thus measuring it’s density – 300DU is highest level of protection

7. Destruction of the Ozone Layer
Ozone is both created and destroyed by the action of UV rays on oxygen molecules
Chlorine has been found to be major cause of ozone depletion.
UV rays react with chlorine and cause a chain reaction. One chlorine molecule can destroy 100,000 ozone molecules

8. Satellite image of ozone hole (pink area) over Antarctica, 9-25-95

9. Chlorofluorocarbons (CFC)
CFCs invented by Dupont, trade name Freon in 1928
Nonflammable, nontoxic, stable, non corrosive, odorless, low boiling point
Used as refrigerants, in manufacturing processes, as cleaning solvents, as propellants in aerosol cans

10. Chlorofluorocarbons (CFC)
Throughout the 60’s & 70’s scientists learned that CFCs can stay airborne for decades. Taking as much as 8 – 10 years to reach the stratosphere
In the stratosphere CFCs are broken down by UV rays. Chlorine & fluorine molecules are released.
Millions of tons of CFCs are currently aloft in our atmosphere, it will take several hundred years for it all to be depleted.

11. The Ban Begins
In the late 70’s the U.S. Canada, Norway & Sweden banned CFCs in aerosol sprays
1987 Montreal Protocol signed by 150 nations, phased reduction of annual CFC releases
CFC production totally banned as of Jan. 1996
If ban not in place, ozone depletion estimated to grow by .5% annually
Currently hole of the size of the U.S. Size and depletion percentage varies with seasonal changes

12. What does this mean for me?
Refrigerants used in Automobiles have changed, and may change again
Strict service procedures must be followed
Strict penalties for law breakers
Certification programs for technicians handling refrigerants