This reading introduces some of the main details of the ozone-CFC issue. The nature of CFCs, their uses, and the risks of ozone are discussed, and a brief history of CFCs is given.

There are questions you may raise to the class concerning the history behind CFCs. Can anyone be blamed for using CFC in the past, given the needs and knowledge of the time in which CFCs were invented? How much should the creators and promotors of CFCs have been responsible for knowing at the time CFCs were introduced? Even if the dangers of CFC use known at the time of their invention, what were the costs of not using CFCs? Early refrigerants like ammonia and sulfur dioxide were much more dangerous environmentally. Simply not using refrigeration would cause high rates of illness and death from eating spoiled food. In warmer climates air conditioning is vital where summer temperatures can cause heat stroke among the sick and elderly. Have the benefits of CFCs justified their use for a limited period of time until today when safer refrigerants have become available? Use these and other questions that occur to you to stimulate critical thinking among the students in connection with this reading.

Relevant National Science Education Standards

Physical Science — The reading reinforces the molecular nature of matter.

Science and Technology — The reading introduces the principles behind refrigeration.

Science in Personal and Social Perspectives — The reading involves an environmental quality issue which is also a human-induced health hazard, plus the use of science in overcoming this global challenge.

Next: How Do We Know Ozone is Missing?