World Ozone Day 2023

1 min read
World Ozone Day 2023 Blog Image


Ministry of Environment, Forest and Climate Change (MoEF&CC) recently celebrated the 29th World Ozone Day.

About World Ozone Day:

  • World Ozone Day, or International Day for the Preservation of the Ozone layer, is observed annually on September 16.
  • It is celebrated every year to spread awareness among people about the depletion of the Ozone Layer and the measures taken/ to be taken to preserve it.
  • The theme for World Ozone Day 2023 isMontreal Protocol: fixing the ozone layer and reducing climate change”.
  • History:
    • In 1994, the UN General Assembly proclaimed 16 September the International Day for the Preservation of the Ozone Layer, commemorating the date of the\signing, in 1987, of the Montreal Protocol, on substances that deplete the Ozone layer. 
  • The protocol was signed on September 16, 1987, in Montreal, Canada, to address the depletion of the ozone layer.

What is the Montreal Protocol?

·         It is an international treaty that aimed to phase out the production and consumption of ozone-depleting substances, primarily chlorofluorocarbons (CFCs), halons, carbon tetrachloride, and other chemicals.

·         These substances were commonly used in refrigeration, air conditioning, and aerosol propellants.

·         Kigali Agreement:

o   It is an amendment to the Montreal Protocol.

o   It was adopted on October 15, 2016, in Kigali, Rwanda, as an extension of the Montreal Protocol.

o   While the original Montreal Protocol focused on phasing out ozone-depleting substances, the Kigali Amendment addresses the phase-down of Hydrofluorocarbons (HFCs), which are used as replacements for those ozone-depleting substances.

o   The primary goal of the Kigali Amendment is to reduce the production and consumption of HFCs, with the aim of mitigating their contribution to global warming.

What is Ozone?

·         Ozone is a gas made up of three oxygen atoms (O3).

·         It is both a natural and a man-made product that occurs in the Earth's upper atmosphere (the stratosphere) and lower atmosphere (the troposphere).  

·         Ozone in the stratosphere, known as the “ozone layer,” occurs naturally and forms a protective barrier that prevents ultraviolet sunlight (UV-B) radiation from the sun from reaching the Earth’s surface and harming plant and animal life. This is commonly referred to as “good ozone.”

·         Tropospheric or ground-level ozone – what we breathe – is formed primarily from photochemical reactions between two major classes of air pollutants, volatile organic compounds (VOC) and nitrogen oxides (NOx).  

·         At ground level, high concentrations of ozone are toxic to people and plants.


Q1) What are chlorofluorocarbons (CFCs)?

Chlorofluorocarbons (CFCs) are nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine. They were first developed in the early 20th century and gained widespread use in various industrial and consumer applications due to their stability, non-toxicity, and non-flammability. They are used in the manufacture of aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants. CFCs are classified as halocarbons, a class of compounds that contain atoms of carbon and halogen atoms. Their use has significantly declined due to their harmful effects on the environment, particularly on the ozone layer. 

Source: Ministry of Environment, Forest and Climate Change celebrates 29th World Ozone Day