Scientists have reported that a majority of the emissions originated from Eastern Mainland China, which accounted for 60% ± 40% of the global CFC-11 increase. EIA investigations uncovered widespread use of CFC-11 in China’s polyurethane (PU) foam sector, with over 85% of the companies surveyed confirming use of CFC-11 in their operations. China has reported the detection of three confirmed CFC-11 production sites, which were demolished by authorities; a total of 43 tonnes of CFC-11 were seized and 42 enterprises were found to be using CFC-11.

China is a Party to the Montreal Protocol on Substances that Deplete the Ozone Layer and its Amendments, including the Kigali Amendment on HFCs. The country has established licensing and quota systems for the import and export of ozone‑depleting substances (ODS) and has reported seizures of illegal trade, including undeclared HCFC‑22 shipments intercepted by Chinese customs. The profile documents China’s phase‑out schedules, control measures, and compliance status under the Protocol.

The 2018–2020 observations revealed "unexpected" CFC‑11 emissions and showed that **a large fraction of the unexpected emissions originated from eastern China** based on regional observations from multiple sites. It states that **global CFC‑11 emissions declined after 2018, dropping to 45 ± 10 Gg in both 2019 and 2020**, suggesting the elimination of most of the unexpected emissions occurring after 2012. The assessment notes that emissions from northeastern China explain **60 ± 40% of the 2012–2018 increase and 60 ± 30% of the subsequent decrease**, and concludes that enforcement actions led to a sharp decline in these emissions, avoiding substantial delay in ozone-layer recovery.

China reports that it "attaches great importance to the implementation of the Montreal Protocol" and has "taken continuous actions to improve its laws and regulations, reinforce law enforcement capacity, intensify law enforcement actions, establish monitoring network and increase information disclosure" in relation to ozone‑depleting substances. The Ministry of Ecology and Environment (MEE) notes that **two underground factories producing CFC‑11 illegally in Liaoning Province and Henan Province were demolished in July 2018**, and that six enterprises using CFC‑11 illegally were punished and fined 1.4 million yuan. It further reports that from June to August 2019, joint enforcement groups inspected **656 system houses and foam companies in 11 key provinces**, testing products and ordering destruction of non‑compliant goods, while also requiring enterprises generating carbon tetrachloride (CTC), the main raw material for CFC‑11, to install online monitoring systems.

An unexpected rise in emissions of the ozone‑destroying gas CFC‑11 was traced to northeastern China. Using atmospheric measurements and inverse modelling, researchers found that factories in the country’s northeast are the likely source of the spike in CFC‑11 released to the atmosphere, indicating production and use in violation of the Montreal Protocol. The study concluded that these new emissions from eastern China were large enough to slow the recovery of the ozone layer.

China's ozone-depleting substances (ODS) phase-out has experienced an accelerated period in recent years. Two Chinese companies that illegally produced CFC-11 were resolved, and four companies that illegally used CFC-11 were penalized in 2018. These enforcement actions were part of China’s implementation of the Montreal Protocol and domestic regulations aimed at eliminating remaining illegal production and use of CFC-11.

In contrast to the expected decline, global CFC-11 emissions increased after 2012. Atmospheric measurements from stations in South Korea and Japan indicate that emissions from eastern mainland China, particularly the provinces of Shandong and Hebei, increased by about 7.0 ± 3.0 Gg yr−1 from 2008–2012 to 2014–2017. This regional increase accounts for approximately 40–60% of the observed global rise in CFC-11 emissions since 2013, implying new production and use of CFC-11 in violation of the Montreal Protocol.

Following the previously reported increase in CFC-11 emissions after 2012, we show that emissions of CFC-11 from eastern China declined by 5.0 ± 1.6 Gg yr−1 between 2014–2017 and 2019. The decline in emissions from eastern China accounts for about 60% of the global reduction in CFC-11 emissions over the same period, bringing global emissions back towards levels expected in the absence of new production. These results suggest that measures taken in China to address illegal CFC-11 production and use have been effective.

Carbon tetrachloride (CCl4) is a long‑lived ozone‑depleting substance whose dispersive uses have been phased out globally under the Montreal Protocol since 2010, yet substantial emissions persist. Based on long‑term atmospheric observations from a Chinese monitoring network and inverse modelling, the study identified substantial CCl4 emissions in China during 2011–2021, accounting for approximately half of global CCl4 emissions. The authors report that a large portion of these emissions in China likely originates from unknown industrial sources beyond allowed feedstock uses, CFC‑11 production-related activities, and by‑product emissions in chlorine‑related processes, although they note indications that these unaccounted‑for emissions may have slightly decreased over 2011–2021.

This study uses new atmospheric observations and inverse modelling to estimate emissions of hydrochlorofluorocarbons (HCFCs) from China. It finds that China contributed nearly half of global HCFC emissions in 2022, with HCFC‑22, HCFC‑141b, and HCFC‑142b having the largest emissions among all HCFCs. The paper notes that HCFCs are transitional ozone‑depleting substitutes controlled under the Montreal Protocol, and that continuous observations since 2022 will assist in assessing China’s compliance and its impact on the recovery of the ozone layer.

CSIRO reports on research published in Nature that used a global network of monitoring stations to trace a mysterious rebound in emissions of the ozone‑depleting chemical CFC‑11 to eastern China. According to the data, 40–60% of the increase in global CFC‑11 emissions seen since 2013 is due to possibly illegal industrial activity in the Chinese provinces of Shandong and Hebei. The study indicates that new emissions of about 7,000 tonnes per year of CFC‑11 from eastern China were detected, and notes that Chinese authorities have identified and closed down some illegal production facilities in response.

Researchers say that they have pinpointed the major sources of a mysterious recent rise in a dangerous, ozone-destroying chemical. This new study says this is mostly being caused by new gas production in eastern provinces of China. The authors conclude that some 40-60% of the increase in global emissions of CFC-11 is coming from provinces in eastern China, with a 110% rise in emissions from these parts of China for the years 2014-2017 compared to 2008-2012.

Recent research reveals a sharp drop in emissions of a banned ozone-depleting chemical after China cracked down on its illegal production. Two Nature studies found that emissions of CFC-11, an ozone-damaging gas, had spiked in recent years, with most of the increase traced to China’s industrial provinces of Shandong and Hebei and linked to factories making polyurethane foam. After these links were made public, Chinese authorities launched enforcement actions and the studies now show that CFC-11 emissions from China have fallen significantly, putting the recovery of the ozone layer ‘back on track’. Scientists say the temporary spike was caught and reversed before it posed a major threat to overall ozone recovery.

Scientists and researchers with the Environmental Investigation Agency (EIA) were able to trace around 60% of the illegal emissions of CFC-11 to eastern China, where the banned chemical was widely used as a blowing agent in polyurethane foams. But two studies published in Nature reported that atmospheric concentrations of CFC-11 had once again dropped significantly by late 2019, falling by about 1% a year — the fastest on record — showing that the world was back on track to repairing the damage to the Earth's ozone layer by mid-century. Using data from air-monitoring stations, scientists determined that the largest source of the global increase in rogue emissions attributed to factories in eastern China were no longer active.

Atmospheric monitoring has tracked rogue emissions of ozone-destroying chlorofluorocarbons to northeast China. Members of the team gathered data from monitoring stations in South Korea and Japan that show emissions of CFC-11 from eastern mainland China—particularly the provinces of Shandong and Hebei—more than doubled from 2008–12 to 2014–17, an increase of about 7,000 metric tons per year. That increase accounts for roughly half of the global rise in CFC-11 emissions since 2013, suggesting prohibited CFC production in the region.

A new study published in Nature pins down the source of 7,000 metric tons a year of new CFC-11 emissions to the provinces of Shandong and Hebei on the northeastern coast of China. The bulk of these emissions are believed to come from small factories that are using CFC-11, in violation of the Montreal Protocol, to manufacture foam insulation used in refrigerators and buildings. As of November 2018, Chinese enforcement officers had identified only 10 instances of continuing CFC-11 production, despite visiting 1,172 production plants.

On 9 April 2025, China’s Ministry of Ecology and Environment and other agencies issued the "National Plan on the Implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer (2025–2030)." The Plan strengthens China’s management of ozone‑depleting substances (ODSs) and hydrofluorocarbons (HFCs). Among its measures, it prohibits manufacturing refrigerators and freezers using HFCs as refrigerants from 1 January 2026, and sets bans from 2029 on manufacturing certain air‑conditioning and refrigeration equipment using high‑GWP refrigerants. The Plan also calls for further strengthening the monitoring, measurement and reporting of HFC‑23 by‑production from HCFC‑22 production facilities and promoting deployment of HFC‑23 resource reutilization technologies.

An international group of researchers reported in 2018 that the expected decline in atmospheric CFC-11 had slowed by about 50% since 2012, indicating renewed emissions. Their analysis pointed to East Asia as the source. A report by the Environmental Investigation Agency found that 18 factories in 10 Chinese provinces admitted using banned CFCs in plastic foam production because they are cheaper and produce better-quality foam. Scientists warned that a rise in CFC emissions could put at risk the healing of the ozone layer by delaying its recovery, although the Montreal Protocol has already led to major reductions in ozone-depleting substances worldwide.

This academic analysis discusses China’s response to the discovery of unexpected CFC‑11 emissions after 2012, noting that international measurements linked a large share of the increase to eastern China. It states that **China’s subsequent enforcement actions against illegal CFC‑11 production led to a sharp decline of these unexpected emissions and avoided any substantial delay in ozone layer recovery**. The paper situates CFC‑11 within China’s broader obligations under the Montreal Protocol and emphasizes the role of domestic regulation and enforcement in curbing ozone‑depleting substances.

CFC-11 is a potent ozone depleting gas and has a global warming potential 4,750 times that of carbon dioxide. Despite a global ban on CFC-11 since 2010, a 2018 study published in Nature found levels of CFC-11 had risen since 2012, with scientists concluding that between 40% and 60% of the increase came from eastern China. The latest Nature study estimated that between 90,000 and 725,000 tonnes of CFC-11 were produced and embedded in products like foams and gases between 2013 and 2019. It also found that levels of CFC-11 over east Asia fell in 2019, indicating that a Chinese government crackdown on producers and buyers of illegal CFC gases is working.

A State Department fact sheet on China’s environmental practices notes that, despite global controls under the Montreal Protocol, scientists identified an increase in emissions of the phased‑out, ozone‑depleting substance CFC‑11 from eastern China between 2014 and 2017. It states that the United States has led an international response, pressing China to meet its obligations under the Protocol and to improve monitoring and enforcement against illegal production and use of ozone‑depleting chemicals.

The publication explains that **China has been the world's leading consumer and producer of ozone‑depleting substances (ODS) since 1996**, with CFC‑11, CFC‑12, and halon‑1211 being the most prevalent historically. It notes that the Montreal Protocol required developing countries to completely phase out production and consumption of CFCs and halons by 2010, and that China "ratified the London Amendments to the Montreal Protocol in 1991 and the Copenhagen Amendments in 2003" and has taken steps to comply. The report frames China as a major historical source of ODS but within the context of international phase‑out schedules and compliance mechanisms, rather than ongoing unrestricted emissions.

This study analyses how China’s implementation of the Montreal Protocol has affected emissions of major ozone‑depleting substances. Using industrial data and atmospheric measurements, the authors show that controls under the Protocol have led to significant reductions in emissions of chlorofluorocarbons (CFCs) and other long‑lived ODSs compared to a no‑policy scenario. However, they also identify remaining emissions from transitional substances such as HCFCs and highlight that China has been a major source of global HCFC emissions, which are scheduled for phase‑out under the Protocol’s later amendments.

Emissions of CFC-11, a dangerous chemical that harms our planet's life-protecting ozone layer, are back on the decline after an unexpected spike lasting more than half a decade, two new studies find. Later research, triangulating on the sources of the emissions, showed that approximately 40–60% of the global uptick in emissions originated from an industrialized region in eastern mainland China. The two papers agree that both globally and in China, CFC-11 emissions have returned to pre-2013 levels, before the anomalous behavior occurred, and the emissions reduction observed in eastern China accounts for 60% of the global decline.

The main causes of ozone depletion and the ozone hole are manufactured chemicals, especially halocarbon refrigerants, solvents, propellants, and foam-blowing agents such as chlorofluorocarbons (CFCs) and halons. A study published in Nature found that since 2013, emissions predominantly from northeastern China have released large quantities of the banned chemical CFC-11 into the atmosphere, and scientists estimated that without action, these emissions would delay ozone-hole recovery by about a decade. Overall, atmospheric concentrations of most ozone-depleting substances have been declining due to the Montreal Protocol, and marked decreases in column ozone have been followed by early signs of recovery.

In a summary of its work, the Environmental Investigation Agency (EIA) states that following its 2018 exposé of illegal CFC‑11 production in China, the Chinese government reported that it had **phased out 280,000 tonnes of ozone‑depleting substances in 2018**. The post highlights that EIA’s investigation prompted nationwide inspections and enforcement actions by Chinese authorities against illegal CFC‑11 use in polyurethane foam production, demonstrating both the scale of prior non‑compliance and the subsequent measures taken to reduce emissions.

Under the 1987 Montreal Protocol, production of most ozone-depleting chlorofluorocarbons such as CFC-11 was phased out globally, with developed countries ending production by the mid-1990s and developing countries, including China, required to halt production by 2010. As a result, legitimate global CFC-11 production and consumption dropped to near zero, and the remaining emissions mainly originate from "banks" of CFC-11 contained in existing foams and equipment rather than ongoing legal factory production.