A chronology of events relateing to HCFCs and HFCs

The more we cool the planet, the warmer the planet gets. Wide-scale application of chemicals in refrigeration and air conditioning has resulted in the depletion of a significant volume of the ozone layer. In 1985, ground-based measurements by the British Antarctic Survey recorded substantial ozone loss, which since has become better known as the ‘ozone hole’. Reported by the European Space Agency, the size of the ozone hole reached about 27 million square kilometres in 2008, as compared to 25 million square kilometres in 2007.

When discovered in the 1920s, chlorofluorocarbons (CFCs) were considered “wonder” chemicals, because they were neither flammable nor toxic and were stable for long periods, making them ideal for numerous applications, including serving as refrigerants in the HVACR industry. However, in 1973, scientists discovered that these very chemicals could destroy ozone molecules and damage the shield protecting our atmosphere. In fact, the ozone layer is what absorbs the ultraviolet (UV) rays from the sun, without which the temperature of the earth’s atmosphere would rise to levels that would make it impossible for life to exist on the planet.

However, it is not the CFCs themselves that destroy the ozone layer but rather certain of their decomposed products that do so. Scientists, Sherwood Rowland and Mario Molina, who shared the 1995 Nobel Prize in Chemistry for their contribution to stratospheric ozone chemistry, postulated that “when CFCs reach the stratosphere, UV radiation from the sun causes these chemically-stable substances to decompose, leading to the release of chlorine atoms. Once freed from their bonds, the chlorine atoms initiate a chain reaction that destroys substantial amounts of ozone in the stratosphere.”

In effect, the chlorine atom serves as a “catalyst” and is not actually consumed by the reaction. This means, however, that each chlorine atom introduced into the stratosphere can destroy thousands of ozone molecules. Therefore, the rate of ozone destruction at any given place, and time, strongly depends on the amount of chlorine present. It has been estimated that a single chlorine atom could destroy as many as 100,000 ozone molecules.

HCFCs (hydro-chlorofluorocarbons) became the substitute for CFCs, owing to their low- or zero-ozone depleting potential. However, despite being a much lower contributor to ozone depletion, the molecular composition of HCFCs is still similar to CFCs. Therefore, HCFCs still pose a threat to the ozone layer. The world recognised that the two refrigerant families, CFCs and HCFCs, most often used in air conditioning systems, were destroying the ozone layer.

Discovery of the ozone hole alarmed the general public and governments, as a result of which a group of concerned countries came together to facilitate action to solve this international environmental crisis, thus paving the way for the treaty, now known as the Montreal Protocol on Substances that Deplete the Ozone Layer. On 16 September, 1987, the Montreal Protocol was signed into existence by 180 nations, to target CFCs and HCFCs as ozone-depleting substances.

The Montreal Protocol stipulates that CFCs and HCFCs be phased out over a 40-year period that began in 1995. Moreover, in response to the Protocol, a new family of refrigerants, hydrofluorocarbons, was developed. HFCs (such as HFC-134a, HFC-407C and HFC-410A) are ozone-friendly and will not be phased out.

Scientists predict that ozone depletion will reach its worst point during the next few years, and then thanks to the Montreal Protocol, gradually reverse until the ozone layer returns to normal, assuming that the Montreal Protocol is fully implemented. The ozone layer is expected to return to its pre-1980s state by 2060-2075, more than 70 years after the international community contracted to take action.


As a signatory of the Montreal Protocol in 1989, the UAE is following the phase-out dates for developing countries, classified in Article 5 under the Montreal Protocol. In accordance with the Montreal Protocol, the UAE will ban the import of CFCs in January 2010. Also, there is no production of ozone-depleting substances taking place in the UAE. Furthermore, according to the Environment Agency in Abu Dhabi, the import and consumption of ozone-depleting substances has remained fairly stable, with 448 tonnes of CFCs consumed in 1990 and 423 tonnes in 2001. “Consumption of all ozone-depleting substances, measured in ODP, fell from 723,400 tonnes in 1986 to 644,406 tonnes in 2004,” the Agency says.

In the case of HCFCs, the Montreal Protocol allows for the unrestricted, continued use of recycled, recovered and stockpiled supplies of refrigerant after the published phase-out dates, plus the import of these recycled and recovered supplies. The agreement stipulates a baseline reduction by 2013, with a further goal to reduce consumption by 10% by 2015, 35% by 2020, and 67.5% in 2020. From 2030, only existing equipment will be serviced, and as of 2040, there will be a full ban on new equipment that use HCFCs.

Additionally, the UAE is also a signatory of the Kyoto Protocol. In 2005, His Highness Sheikh Khalifa bin Zayed Al Nahyan, the President of the UAE and Ruler of Abu Dhabi, issued a Federal Decree ratifying the Kyoto Protocol. In the process, the UAE became one of the first major oil-producing countries to do so. As per the Kyoto Protocol, as a Non-Annex 1 Country, the UAE is not obligated to reduce its emissions. Nonetheless, the UAE has already taken several initiatives to do so. For instance, by moving towards zero-flaring technologies in oil and gas production, the flaring from oil and gas production was reduced from approximately 7.5 million cubic metres per day to 2.5 million cubic metres per day between 1995 and 2004.