Mystery of rising ozone depleting gas solved?
Published: 10 Jul 2018

Recently, scientists have been puzzled by a mysterious increase in emissions of CFC-11; an ozone depleting substance which has been fully banned since 2010. However, they may have now solved the mystery of why levels are not decreasing as expected.

Ozone depleting substances are extremely harmful to the earth's ozone layer, which protects the surface of the earth from the sun's ultraviolet radiation. As a result, the Montreal Protocol was finalised in 1987 and was signed by every country in the world. It saw the beginning of a phase out of CFCs which are known to cause widespread damage to the ozone layer.

However, two months ago a study was published which showed that the expected decline in CFC-11 had almost stopped, and speculation was rife as to why.

It seems the main source of the rise could be the home construction industry in China.

CFC-11 can be effectively used as a blowing agent when making polyurethane foam. Using it in this way allows the foam to expand into rigid insulation panels that are used in homes. Using this knowledge, researchers from the Environmental Investigations Agency (EIA) contacted manufacturers in 10 different provinces in China and discovered that CFC-11 is still used in the majority of production of polyurethane insulation.

The reason for this is that CFC-11 is better quality and cheaper than the alternatives, making it more attractive to producers wishing to maximise profits. Even though the gas is banned and its manufacture and use is illegal, it seems that enforcement of the law is poor, resulting in the continued use of the environmentally-damaging substance.

Avipsa Mahapatra from the EIA, told the BBC: "We were absolutely gobsmacked to find that companies very openly confirmed using CFC-11 while acknowledging it was illegal. The fact that they were so blasé about it, the fact that they told us very openly how pervasive it is in the market, these were shocking findings for us."

Back in January, NASA confirmed that the hole in the ozone layer was closing and they expected it to "heal" by 2060. However, continued use of such gases could seriously hinder the efforts made to help the ozone layer recover from the damage humans have done to it. It is, after all, in our best interests to help the ozone layer recover, as an increased amount of UV radiation from the sun reaching the surface because of a thinning or depletion of ozone could result in skin cancer, eye damage, damage to marine life and reduced crops.

It is expected that China will launch a full investigation and target the actual production of CFC-11 rather than the products that contain it. Delegates to the Montreal Protocol are expected to meet soon to come up with a plan to tackle the issue.

For more information, see:

  • Regulation (EC) 1005/2009, on substances that deplete the ozone layer;
  • Ozone-Depleting Substances Regulations SI 2015/168.