Which one among the following is responsible for formation of‘Ozone Holes’ in the stratosphere ?

Chlorofluorocarbons (CFCs) are the primary substances responsible for the formation of the 'ozone hole' in the stratosphere [2]. These synthetic chemicals, used as refrigerants and aerosol propellants, drift into the upper atmosphere where they are exposed to high-energy ultraviolet (UV) radiation [4]. This exposure causes CFC molecules to break apart, releasing free chlorine atoms [5]. These chlorine atoms act as catalysts in a destructive cycle; a single chlorine atom can break down over 100,000 ozone molecules by converting them into oxygen molecules [5]. While UV radiation is necessary to trigger this chemical release from CFCs, it is also responsible for the natural production of ozone from oxygen [2]. Other options like Benzopyrene and hydrocarbons are pollutants typically associated with incomplete combustion or tropospheric smog rather than stratospheric ozone depletion [7].

Sources

1. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 11: World Climate and Climate Change > Greenhouse Gases(GHGs) > p. 96
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 13: Our Environment > 13.2.1 Ozone Layer and How it is Getting Depleted > p. 213
3. [4] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 7: Climate Change > 2. greenhouse gases > p. 11
4. [5] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 19: Ozone Depletion > The chemical reaction > p. 268
5. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 20: Earths Atmosphere > Ozonosphere > p. 276
6. [7] https://www.atsdr.cdc.gov/toxprofiles/tp69.pdf