CFC-11 molecule diagram
CFC-11 or Trichlorofluoromethane - the ozone-eliminating gas that we thought had gone for good...

In May, scientists from the University of Bristol discovered industry in Eastern China is behind the recent shock rise in ozone layer-destroying CFC emissions. Birmingham chemist, Dr Simon Cotton, has written about the molecule behind the rise, Trichlorofluoromethane (CFC-11), and why we should all be concerned about its continued usage.

Writing for the long-running Molecule of the Month website, Dr Cotton expanded:

"The Environmental Investigations Agency (EIA) discovered that CFC-11 was still widely available and freely used in China, even though CFCl3 has been completely banned in all developing nations – which includes China – since 2010. CFC-11 isn’t just a refrigerant substance, it makes a very efficient ‘blowing agent’ for the expanded polystyrene foam that is used to make thermal insulation by Chinese builders, who prefer it to alternatives. In May 2019 a report in Nature by a team from Bristol University showed that emissions were definitely originating in East Asia, almost certainly the provinces of Shandong and Hebei in the north-east. Monitoring stations in Japan and South Korea detected the gas, and then knowledge of the wind directions were used to trace its origins back into Asia."

Cotton added:   

"Chinese authorities say that the illegal CFC emissions came from 'rogue factories'. These factories should be using other substances like hydrofluorocarbons - HFCs - which do not damage the ozone layer (though they are big greenhouse gases). If the Chinese government successfully track down those people illegally using CFCl3 and drive it out of use, then that is good news, but China is a huge country and they have a big task on their hands. We do not know why the Chinese authorities did not pick up this problem earlier. Another issue is that, in addition to the building firms using it, there are some companies actually making CFC-11."

You can read the full article by following the link below:

Trichlorofluoromethane - Molecule of the Month