U.N. officials said they would speed up discussions on banning ozone-eating chemicals.

Others are as broad as the atmosphere, including treaties that ban ozone-destroying chemicals.

LEAD: Banning widely used chemicals is hard enough, especially in advance of proven harm.

Ronald Reagan's administration led the international drive to ban chemicals destroying the ozone layer, probably the greatest environmental success story.

Government efforts to ban or restrict other chemicals taken by athletes, like ephedra, have dragged on for years.

Sometimes regulatory agencies ban chemicals that later prove safe.

She signed a treaty banning dangerous "persistent organic" chemicals found in pesticides.

Those who favor banning chemicals that cause cancer in laboratory animals say the risk is particularly great with apples because children eat so many.

I am particularly pleased about the opportunity it gives countries to ban dangerous chemicals throughout their territories in order to protect their drinking water.

One of those steps is to ban chemicals suspected of depleting the ozone layer.