BEIJING - The Ozone Secretariat of the United Nations Environment Program (UNEP) conferred a honor to the Chinese government for its contribution to ozone layer protection in an event marking this year's International Ozone Layer Protection Day that fell on Sunday.

Zhang Lijun, vice minister of environmental protection, said at the event that China has phased out more than 100,000 tons of ozone depleting substances (ODS) since 1991, an amount that accounted for around half the total disposed of by the developing countries.

Since signing the Montreal Protocol on Substances that Deplete the Ozone Layer in 1991, China continued to improve its management over ODS and phase out ODS production and consumption, contributing greatly to global efforts in ozone layer protection, according to Zhang.

China will face an "extremely arduous" task in meeting the next phase goal of ODS elimination set by the Protocol, he said.

Ozone shields the planet from the harmful ultraviolet-B radiation of the sun. It also completely screens out lethal UV-C radiation.

Signed by 24 nations in 1987, the Montreal Protocol set a global agenda for ODS elimination.