National Ozone Unit (NOU) was established on September 1st 2007 in the frame of the project Institutional strenghhtening for the implementation of Montreal protocol. From March 1st 2009 it works within the EPA as focal point for the implementation of Montreal protocol. The main duties of NOU are participation in preparation and implementation of the national legislation, carrying out the follow-up and coordination of national and international activities related to the Vienna Convention for the protection of the ozone layer and Montreal Protocol on substances that deplete the ozone layer and controlling of consumption and use of ozone depleting substances (ODSs) and phasing them out within the country phase-out schedule.

The ozone layer is a region of high ozone concentration in the stratosphere, 20 to 30 kilometres above Earth's surface. The ozone layer acts as an invisible shield and protects us from harmful ultraviolet (UV) radiation from the sun. In particular, the ozone layer protects us from the UV radiation, known as UV-B, which causes sunburn. Long-term exposure to high levels of UV-B can severely damage most animals, plants and microbes, so the ozone layer protects all life on Earth.

Man-made chemicals containing halogens were determined to be the main cause of ozone loss. These chemicals are collectively known as ozone-depleting substances (ODSs). The most important are chlorofluorocarbons (CFCs), which at one time were widely used in air conditioners, refrigerators and aerosol cans. Other chemicals, such as hydrochlorofluorocarbons (HCFCs), halons and methyl bromide also deplete the ozone layer.