The ozone layer in the stratosphere can absorb the majority of harmful ultraviolet rays and protect the earth's organisms from harm. However, some man-made chemicals used extensively by human beings have seriously damaged the ozone layer, resulting in a large number of harmful ultraviolet rays directed at the earth, causing serious damage to the earth's biological and ecological environment. These ozone-depleting chemicals are collectively referred to as ozone-depleting substances (ODS) by the scientific community. In order to protect the ozone layer and phase out ODS, international community signed the “Vienna Convention for the Protection of the Ozone Layer” (hereinafter referred to as the Convention) and the “Montreal Protocol on Substances that Deplete the Ozone Layer” (hereinafter referred to as the Protocol) in 1985 and 1987 respectively. China acceded to the Convention and the Protocol in 1989 and 1991 respectively.

Controlled substances in Chloro-fluoro-carbon (CFC) are listed in Annexes A and B. China's chemical sector produces six CFC products eliminated under the Protocol, namely, Annex A, Group I CFC-11 (trichloro-fluoromethane), CFC-12 (dichloro-difluoromethane), CFC-113 (trichloro-trifluoroethane), CFC-114 (dichloro-tetrafluoroethane), CFC-115 (monochloro-pentafluoroethane) and Annex B, Group I CFC-13 (trichloro-trifluoromethane).

Since China’s accession to the Protocol in 1991, the protection of the ozone layer in the chemical sector has been under the leadership of the Ministry of Environmental Protection, with the assistance of the Ministry of Chemical Industry, the State Petroleum and Chemical Industry and the China Petroleum and Chemical Industry Association/Federation, and with the support of the China Fluorosilicone Organic Materials Industry Association, universities, scientific research institutes and international organizations. According to the "China Chemical Sector CFC Production Overall Elimination Plan" (hereinafter referred to as the "Sector Plan"), CFC production has been gradually reduced and eventually eliminated (except for essential uses). 36 manufacturing enterprises’ CFC production lines have been completely closed down, and about 50,351 ODP tonnes of CFC production have been eliminated, which has made outstanding contributions to the realization of China's goal of eliminating CFC in advance. During the implementation period of the Sector Plan, China has completed the required elimination quantities on time annually. The elimination of CFC production in China is progressing.

In order to ensure the progress of CFC elimination in chemical industry, China has carried out a lot of work in the early stage. Under the unified planning of the Ministry of Environmental Protection, the Ministry of Chemical Industry organized and compiled the “Strategy for Reducing Ozone-depleting Substances in China's Chemical Industry”, carried out a study on the calculation method of "CFC Device Closure Compensation Cost". It has put forward the idea that the production sector should have the same right to receive funding from the Multilateral Fund as the consumer sectors, and obtained the approval of the Executive Committee of the international community at the national level. Under the leadership of the Planning Committee, the Ministry of Chemical Industry organized the "Eighth Five-Year Plan" national key scientific and technological research work on the development of CFC alternative process, and achieved a number of pilot-scale results, which made a good technical reserve for the construction of alternative devices in advance.