research on finding safer substitutes for ods like cfcs, halons, and carbontetrachloride are underway. In fact certain replacements have already been made and are successfully being used.

cfcs are regarded as being harmful because they damage the ozone layer which helps screen out damaging ultraviolet rays emitted by the sun from reaching the Earth. The degradation of this layer can cause an increase in the occurrence of skin cancer and a reduction in crop yields. Some scientists believe that a severe enough denudation of the layer could lead to the elimination of many species. The phasing out of cfcs was initiated in the