Our Ozone Layer

For starters, here is the definition of the ozone layer:

The Ozone layer is a layer of the Earth's atmosphere containing large amounts of ozone.


Ozone is an allotrope of oxygen and is a pale blue, almost colourless gas. It is non-toxic and small concentrations, but in concentrations of an estimated 100 parts per million, it will bring about many consequences and can prove to be especially dangerous for people with asthma.

The ozone layer is very important since it protects life on Earth from harmful ultraviolet light emitted from the sun. Without the ozone layer, we will suffer from various skin cancers, eye damage and may even bring about genetic disorder.



The Cause of the Depletion of the Ozone Layer

It has been discovered that by scientists that the ozone layer is being depleted by chlorofluorocarbons, compounds made up of carbon, chlorine and fluorine. These compounds, are widely use for propellents for aerosols and coolants in refrigerators etc.


How does CFC deplete the ozone layer?


When aerosol can is used or polystyrene packaging is burnt, CFC molecules escape into the air. These CFC molecules will then undergo homolytic fission in the presence of sunlight to produce chlorine atoms at the stratosphere.Chlorine atoms react with ozone molecules and convert them into oxygen molecules, thus destroying the ozone molecules.

Here is the equation involving the depletion of the ozone layer by chlorine atoms:
Cl + O3 --> ClO + O2
O + ClO --> Cl + O2