We often hear about "good" and "bad" ozone. What is ozone, and what makes it good or bad? People are often confused. Ozone is a gas. Good ozone is made of three oxygen atoms joined together. Likewise, bad ozone is made of three oxygen atoms joined together. Ozone can be good or bad according to where it is found. Good ozone is found high above the Earth in the stratosphere. Bad ozone is found close to the ground in the troposphere.
Good ozone is made by nature. It protects all life on Earth by absorbing harmful rays from the sun. This layer is being destroyed, however, by some man-made chemicals. You may have heard about thinning and even holes in the ozone layer. This is very dangerous.