A study led by the Massachusetts Institute of Technology (MIT), published in December 2018 in the journal Nature Geoscience, identifies another new threat to the ozone layer’s recovery: chloroform—a colourless, sweet-smelling compound that is used in the fluorochemicals supply chain.
Between 2010 and 2015, emissions and concentrations of chloroform in the global atmosphere increased significantly. The source of these emissions appears to be East Asia. If chloroform emissions continue to increase, the researchers predict that the recovery of the ozone layer could be delayed by four to eight years.
Chloroform is among a class of compounds called “very short-lived substances” (VSLS), for their relatively brief stay in the atmosphere (about five months for chloroform).
Chemicals which are classed as VSLS had previously not been considered for regulation because they were expected to be destroyed before reaching the ozone layer. However, emissions from certain parts of the world such as East Asia can be sent up to the ozone layer very quickly through monsoon systems, bypassing the normal destruction that occurs in the lower atmosphere of other parts of the world.
This research was supported by NASA, the National Institute of Environmental Studies in Japan, the National Research Foundation of Korea, the Department for Business, Energy & Industrial Strategy and the Natural Environment Research Council in the UK, the Commonwealth Scientific and Industrial Research Organization of Australia, and other organisations.
In 2018, United Nations announced that the ozone layer, which shields the Earth from the sun’s harmful ultraviolet radiation, continues to recover.
This positive change is a direct result of regulations set by the 1987 Montreal Protocol, a global treaty under which nearly every country in the world pledged to control the production of chlorofluorocarbons (CFCs), the main agents of ozone depletion. As a result of this sustained international effort, the United Nations projects that the ozone layer is likely to completely heal by around the middle of the century.
The initial stage in the manufacture of fluorochemicals is the conversion of acid grade fluorspar to hydrofluoric acid (HF). As part of international phase-down regulations, the Chinese government has implemented production quotas for domestic hydrochlorofluorocarbon (HCFC) producers. In general, these have declined each year (they fell 10% between 2014 and 2015) but remained unchanged from 2016 to 2018. The next step-down according to the Montreal Protocol schedule for article 5 countries is due in 2020, when quotas are expected to be reduced by 35% compared to baseline levels.
Roskill’s NEW Fluorspar: Global Industry, Markets & Outlook report, published in December 2018, breaks down all the major markets for fluorspar, including fluorochemicals, into clear demand forecasts to 2022 and lists Chinese HCFC production quotas by company. Click here to download the brochure and sample pages, or to access further information.