What is Nitrox?
Nitrox is a gas that is generally used for recreational diving. The gas is simply a mixture of oxygen and nitrogen, which in recreational diving terms, is sometimes referred to as ‘enriched air nitrox (EAN)’. The oxygen concentration in the air is normally around 21%, however the oxygen concentration in nitrox is higher. Nitrox refers to any combination with levels of oxygen between 21 and 40 percent- 32% is a common oxygen content used.
The well-used term ‘decompression sickness’ (DCS), also known as ‘the bends’ starts when nitrogen enters the divers bloodstream and as they dive deeper, the pressure will also increase.
When the nitrogen builds up and the diver comes to the surface too quickly (without performing decompression stops), the diver’s body will need time to remove the absorbed oxygen and may experience decompression sickness as a result. DCS is extremely unpleasant and in some cases it can be deadly, which is why so much research has been driven into how we can prevent it from happening.
Instead of using a standard mix, divers started using nitrox as it helps increase your allowed diving time due to offering less nitrogen and more oxygen. This means that less nitrogen can be absorbed into the bloodstream which therefore extends the ‘no decompression limit’, or in other words, you get longer bottom times.
While this does not completely prevent DCS, it reduces the risk of it occurring.
However, divers must also remember not to exceed maximum depth or bottom time!
Another benefit of using nitrox is shorter decompression times, this is because there is less nitrogen to be absorbed in the body, meaning that there is less nitrogen to expel from the body when resurfacing.
While oxygen is a key element to human life, oxygen at higher levels can be harmful to us too, this is called oxygen toxicity. If the oxygen concentration in the nitrox mix is too high, the diver may experience seizures, unconsciousness, breathing difficulty, damage to the lungs and eyes and in worst cases death.
Oxygen toxicity gives no or little warning before you experience these severe symptoms, which is what makes it so dangerous. It is safer to check your gas mix before you dive in order to eliminate risk of oxygen toxicity.