Environmental Protection Agency (EPA) MVAC Certification

What is the average ozone concentration in Earth's atmosphere?

1. 0.1 parts per million

2. 0.2 parts per million

3. 0.3 parts per million

4. 0.4 parts per million

The correct answer is: 0.3 parts per million

The average ozone concentration in Earth's atmosphere is approximately 0.3 parts per million (ppm). This value represents the typical concentration of ozone present in the stratosphere, which plays a critical role in absorbing the majority of the sun's harmful ultraviolet (UV) radiation. Ozone is naturally occurring and is formed through photochemical reactions involving sunlight and oxygen. The stratospheric ozone layer is essential for protecting living organisms from UV rays, thus maintaining ecological balance and safeguarding human health. Understanding this concentration is crucial for individuals preparing for the MVAC Certification, as it relates to environmental standards and regulations governing the use of refrigerants and other chemicals that can impact ozone levels. Recognizing the importance of maintaining this balance reinforces why certain practices around refrigerants, especially those that can deplete ozone, are strictly regulated by the Environmental Protection Agency.