[cs_content][cs_section parallax=”false” separator_top_type=”none” separator_top_height=”50px” separator_top_angle_point=”50″ separator_bottom_type=”none” separator_bottom_height=”50px” separator_bottom_angle_point=”50″ style=”margin: 0px;padding: 45px 0px;”][cs_row inner_container=”true” marginless_columns=”false” style=”margin: 0px auto;padding: 0px;”][cs_column fade=”false” fade_animation=”in” fade_animation_offset=”45px” fade_duration=”750″ type=”1/1″ style=”padding: 0px;”][cs_text]Monitoring and Management > 4. The Atmosphere >
Identify the origins of chlorofluorocarbons (CFCs) and halons in the atmosphere[/cs_text][/cs_column][/cs_row][/cs_section][cs_section parallax=”false” separator_top_type=”none” separator_top_height=”50px” separator_top_angle_point=”50″ separator_bottom_type=”none” separator_bottom_height=”50px” separator_bottom_angle_point=”50″ style=”margin: 0px;padding: 45px 0px;”][cs_row inner_container=”true” marginless_columns=”false” style=”margin: 0px auto;padding: 0px;”][cs_column fade=”false” fade_animation=”in” fade_animation_offset=”45px” fade_duration=”750″ type=”1/1″ style=”padding: 0px;”][cs_text]
- Chlorofluorocarbon (CFC): A haloalkane that contains both fluorine and chlorine atoms, and no hydrogen atoms.
- Halon: Also referred to as a brominated CFC, a haloalkane that contains bromine, chlorine and/or fluorine atoms, and no hydrogen atoms.
- CFCs were developed in the 1930s to replace ammonia as refrigerants.
- CFCs became extensively used as:
- Refrigerants.
- Solvents in dry cleaning.
- Propellants in spray cans.
- Blowing agents for expanded plastic products.
- Halons were developed for the extinguishing of electrical fires.
- Halons became widely used for this purpose, but were never used as extensively as CFCs.
- Through their various uses, CFCs and halons were released into the atmosphere.
- CFCs diffuse into the stratosphere because:
- They are not destroyed by sunlight and oxygen in the troposphere.
- They are insoluble in water, and are thus not ‘washed out’ of the atmosphere.
Dichlorodifluoroethylene, and example of a CFC
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