chlorofluorocarbon

In the early 20th century, Thomas Midgley Jr. personally demonstrated the safety of leaded gasoline and CFC refrigerants, making them commercially successful.

Observations by scientists over the past few months show that ozone depletion in the Arctic has reached a record, according to the World Meteorological Organization (WMO).

According to scientists, ozone holes have recently appeared in the Arctic region. At an altitude of about 20km from the ground, ozone concentrations decreased by 80%.

Research published recently said that the gas used in curing teeth - another name for nitrous oxide - is currently the biggest threat to the Earth's ozone layer.

Starting from January 1, 2010, all CFCs (clorofluorocarbon) degrade ozone layer will be banned from importing into Vietnam.