ECSA: Montreal Protocol and the EU ODS regulation
The UN has begun revising the Montreal Protocol on the protection of the ozone layer and will include halogenated very short-lived substances (VSLS).
Methylene chloride (DCM) belongs to these substances with an atmospheric lifetime of 0.4 years. NGOs are strongly advocating for strict global usage restrictions or even bans of VSLS substances under the Montreal Protocol. Scrutiny of DCM was triggered by an article in Nature, which reported increasing amounts in the atmosphere and also proposed that this could delay the ozone layer repair.
However, this assumption came from unrealistically high growth rates of DCM production, particularly in China. As various media reported on the article, ECSA replied to Chemistry World and other outlets and consulted Dr. Archie McCulloch, who published a paper showing how DCM actually has a negligible effect on stratospheric ozone depletion. Any DCM that does get into the stratosphere rapidly decomposes in the lower stratosphere. The contribution of anthropogenic and natural DCM emissions to the overall total stratospheric chlorine is <1%. This led to a presentation by ECSA, supported by HSIA, at a side event of the Montreal Protocol meeting in November 2017. As most emissions of the solvent originate from developing countries, where DCM is used mainly in emissive applications (particularly in India and other parts of Asia), further regulatory action should focus on minimising emissions in these countries. This has already begun in China.
In parallel, in mid-2017, the EU Commission began the process of revising the EU Ozone Depleting Substances (ODS) regulation, which implements the Montreal Protocol in the EU. ECSA is a recognised stakeholder of this process, and members have provided extensive feedback on the consultation process to simplify and streamline the regulation without comprising its goal to protect the ozone layer.