Ozone is a pale blue gas with the chemical formula O₃, consisting of three oxygen atoms bonded in a bent molecular structure. Discovered in 1839 by German chemist Christian Friedrich Schönbein who named it after the Greek word “ozein” (to smell) for its distinctive sharp, chlorine-like odor, ozone exists as both Earth’s protector and pollutant. In the stratosphere 10-50 kilometers above us, the ozone layer absorbs 97-99% of the Sun’s deadly ultraviolet radiation, making surface life possible. Yet at ground level, this same molecule is a toxic air pollutant that damages lungs and destroys crops. This paradox – essential for life high above but harmful at our level – combined with ozone’s powerful oxidizing properties that can sterilize water or damage rubber, makes it one of the most important yet controversial molecules in environmental science.

Find a review of the 50 most important industrial gases here.

20 Fun Facts About Ozone

Beyond the basics above, what else should we know about Ozone? Check out the 20 fun facts below!

1. Ozone is bent at a 116.8° angle, making it polar and more reactive than straight CO₂ despite similar atomic composition.
2. The molecule is 50% stronger as an oxidizer than chlorine, capable of breaking carbon–carbon double bonds in rubber.
3. Lightning produces 10% of tropospheric ozone, creating that distinctive “fresh” smell after thunderstorms at 0.02 ppm.
4. The ozone hole over Antarctica can reach 28 million km² – three times larger than the continental United States.
5. Ozone glows faint blue in concentrated form and becomes dark blue-black as a liquid at -112°C.
6. The gas decomposes explosively at concentrations above 20%, limiting industrial use despite powerful oxidizing properties.
7. UV-C lamps in hospitals create ozone that must be ventilated – the same process that forms stratospheric ozone naturally.
8. One chlorine atom destroys 100,000 ozone molecules before deactivating, explaining why CFCs are so devastating.
9. Plants close their stomata within minutes of 0.1 ppm ozone exposure, reducing crop yields by 5-15% globally.
10. The molecule absorbs UV at exactly 254 nanometers, coincidentally the wavelength that damages DNA most effectively.
11. Los Angeles ozone levels peaked at 0.68 ppm in 1955 – enough to crack rubber tires within hours.
12. Dobson units measure total atmospheric ozone: 300 DU compressed to surface pressure would be just 3mm thick.
13. Ozone therapy controversially injects O₃ for claimed medical benefits, though FDA bans it as a toxic gas.
14. The stratosphere’s -50°C temperature is perfect for ozone – too warm and it decomposes, too cold and it won’t form.
15. Niagara Falls naturally produces detectable ozone from water mist breaking apart oxygen molecules through mechanical energy.
16. Copy machines create ozone from corona discharge, requiring special filters to meet indoor air quality standards.
17. The molecule lasts only 20-30 minutes at ground level but survives months in the stratosphere’s thin air.
18. Ozone concentrations follow a daily cycle, peaking at 2-6 PM when sunlight drives photochemical smog reactions.
19. Mars has trace ozone that varies 300% seasonally, possibly indicating subsurface water chemistry or even life.
20. Swimming pool “chlorine smell” is actually ozone and chloramines – properly balanced pools have no odor.

Thanks for reading!