Nitrox refers to gas mixture composed of nitrogen and oxygen; which is approximately 78%nitrogen, 21% oxygen, and 1% other gases, primarily argon. The most common use of nitrox mixtures containing higher than normal levels of oxygen is in scuba, where the reduced percentage of nitrogen is advantageous in reducing nitrogen uptake in the body's tissues and so extending the possible dive time, and/or reducing the risk of decompression sickness.
About Nitrox can be listed as follow:
a) Nitrox is technically any mixture of nitrogen and oxygen, but more commonly considered to be
an oxygen-enriched mixture.
b) Oxygen-enriched air has been actively used for more than 30 years, and has existed as a concept
for more than 200 years.
c) Manipulating oxygen levels was essential to certain military operations, and became common in
commercial, scientific, and medical fields as early as World War II.
d) The National Oceanic and Atmospheric Association (NOAA) released the first publicly available
Nitrox tables in 1979, fueling the use of Nitrox in the recreational communities.
e) Nitrox gained significant recreational popularity in the early 1990’s.
f) Bottom time and/or decompression obligation is related to the accumulation of metabolically inert gasses (such as nitrogen). Since Nitrox reduces the percentages of metabolically inert gasses
in the diver’s breathing mixture, it can significantly impact bottom time and/or decompression.
g) Less nitrogen in the diver’s breathing mix allows for longer bottom times and safer dives. For
example, a 60ft (18m) Nitrox dive can last for 100 minutes as compared to 60 minutes on air.
Custom Nitrox mixtures allow divers to maximize their bottom time while reducing the risk of
decompression sickness.
Table : NO DECOMPRESSION LIMITS WITH AIR AND NITROX
