Ozone hole. Abstract artwork showing the Arctic ozone hole as smashed glass over the Earth. The ozone layer in the Earth's upper atmosphere contains ozone (O3), a gas which absorbs ultraviolet (UV) light. Atmospheric pollutants especially chlorofluorocarbons (CFCs), react with the ozone and destroy it. This can result in holes through which UV light can pass. The largest ozone hole is in Antarctica, although there is also one over the Arctic. Large doses of UV light increase the risk of cancer on exposed skin. The discovery of ozone holes has led to a worldwide reduction in the amounts of CFCs used. They were formerly used as propellants and coolant gases.