What harm does Freons produce, making its usage in refrigerators considered unsafe?

Depletion of the ozone layer 

The correct answer is option 2. Depletion of the ozone layer.

The harm caused by Freons (chlorofluorocarbons or CFCs) that makes their usage in refrigerators considered unsafe is the Depletion of the ozone layer.

1. Depletion of the Ozone Layer:

Freons, specifically chlorofluorocarbons (CFCs), have been identified as major contributors to the depletion of the ozone layer in the Earth's stratosphere. Ozone depletion occurs when CFCs are released into the atmosphere and eventually reach the stratosphere.

2. Mechanism of Ozone Depletion:

In the stratosphere, CFCs can be broken down by ultraviolet (UV) radiation from the sun, releasing chlorine atoms. These chlorine atoms then react with ozone (O₃) molecules, breaking them apart. The depletion of ozone in the stratosphere is concerning because the ozone layer plays a crucial role in protecting life on Earth by absorbing harmful ultraviolet radiation.

3. Consequences of Ozone Depletion:

Ozone layer depletion allows more ultraviolet-B (UV-B) and ultraviolet-C (UV-C) radiation to reach the Earth's surface. Increased exposure to UV radiation has adverse effects on human health, including an increased risk of skin cancer, cataracts, and other health issues. It also has detrimental effects on ecosystems, marine life, and materials.

4. International Response:

The recognition of the harmful effects of CFCs on the ozone layer led to global efforts to address the issue. The Montreal Protocol, an international treaty adopted in 1987, aims to phase out the production and consumption of ozone-depleting substances, including CFCs. Substitutes with lower ozone-depleting potential, such as hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs), have been introduced in many applications.

5. Phasing Out CFCs:

The production and use of CFCs have been largely phased out due to their adverse environmental effects. Many countries have successfully transitioned to alternative refrigerants with lower ozone-depleting potential and reduced environmental impact.

In summary, the usage of Freons, particularly CFCs, in refrigerators is considered unsafe due to their role in depleting the ozone layer, leading to potential harmful consequences for human health and the environment. International efforts have been made to address and mitigate the impact of ozone-depleting substances.