OZONE NOUN (ENVIRONMENT)

A colourless unstable gas with a pungent smell and powerful oxidizing properties, which makes up the ozone layer, a layer of naturally occurring ozone in the earth's upper atmosphere that absorbs most of the sun's harmful ultraviolet radiation. Used especially in compounds to do with environmental concerns about the ozone layer: ozone depletion, a reduction of ozone concentration in the ozone layer caused by atmospheric pollution and the build-up in the atmosphere of ozone-depleting chemicals such as CFCs; ozone-friendly, of a product, material, etc.: not containing chemicals which harm the ozone layer (see also -friendly); ozone hole, an area of the ozone layer in which serious ozone depletion has occurred; also used as a synonym for ozone depletion. History and Usage: Concern about the damaging effects of modern industrial chemicals on the ozone layer was expressed by environmentalists as long ago as the seventies, but most of the other terms defined here came to public attention only in the mid eighties, as environmental concerns were in general brought to prominence by the green movement. Public awareness of the potentially damaging effects of creating an ozone hole was possibly heightened by the results of research which linked overexposure to ultraviolet radiation with skin cancers, although the environmental effects of a large ozone hole would be so devastating to weather systems, agriculture, and animal life on the planet that some argued that the cancer risk was a minor concern. Other terms using ozone in this context include ozone-benign, ozone destroyer (and ozone destruction), ozone safe, and ozone-unfriendly (see unfriendlyÜ). Scientists expected from some mathematical models that the next very large ozone hole over Antarctica would occur in 1990. New York Times 23 Sept. 1989, p. 2 Many ozone-friendly aerosols use hydrocarbons as the propellant; these have a higher risk of ignition or explosion if misused. Which? Sept. 1989, p. 431 HCFC-123...has the potential to break down some ozone, although its ozone depletion potential (ODP) has been calculated at only 0.02. New Scientist 15 Sept. 1990, p. 34 First of all, polystyrene loose fill is not made with ozone-depleting CFCs or HCFCs, but with hydrocarbons. Garbage Nov.-Dec. 1990, p. 73