The International Day for the Preservation of the Ozone Layer was proclaimed as 16 September in 1994 by the UN General Assembly. The day was selected to commemorate the signing of the Montreal Protocol on substances that deplete the ozone layer.
1. Ozone was first discovered and isolated by the German-Swiss chemist Christian Friedrich Schönbein in 1839.
2. Ozone is a pale blue gas with a distinctive pungent smell.
3. Schönbein named it ozone from the Greek verb ozein, meaning to smell.
4. One molecule of ozone consists of three oxygen atoms. A molecule of oxygen has only two atoms.
5. The bracing smell of seaside air which people often think is ozone is in fact dimethyl sulphide produced from rotting seaweed.
6. Ozone near ground level may be harmful. A component of smog, it can lead to breathing disorders and chest pain.
7. Harmful ground-level ozone is produced by car and truck exhausts and natural gas production.
8. Good ozone is ozone in the ozone layer of the atmosphere, 10-20 miles high, which protects us from harmful UVB rays from the Sun.
9. The Montreal Protocol to ban ozone-depleting chemicals such as CFCs was signed in 1989.
10. Latest results show that the ozone hole over Antarctica is showing signs of shrinking.
