2006 Antarctic ozone hole. Coloured satellite image of low atmospheric ozone levels over Antarctica on 25th September 2006. Ozone levels are colour-coded, from purple (lowest) through blue, cyan and green to yellow (highest). Ozone absorbs harmful ultraviolet (UV) radiation from the Sun, but its levels are reduced by chlorofluorocarbons (CFCs) and other compounds. CFC production was restricted in 1987 in an effort to protect the ozone layer. 2006's hole set records for extent (over 29.5 million square kilometres) and ozone depletion (to 85 Dobson units), but it is still hoped that the hole will recover fully by the middle of the century. Data from the Ozone Monitoring Instrument on the Aura satellite.