You can dive as deep as 112 feet (ca. 34 m) with 32% Nitrox and 95 feet (ca. 29 m) with 36% Nitrox. There are special tables to find out max depth limits according to the EAN oxygen percentage.<\/strong><\/p>\n\n\n\n Oxygen toxicity is a very complex medical topic. Fortunately, there are only a few easily understood key points that EAN divers must know and apply to their dive planning. There are two forms of oxygen toxicity: <\/p>\n\n\n\n Enriched Air Nitrox MOD will keep the PO2 levels in the safe range.<\/p>\n\n\n\n In the 1970s, the National Oceanic and Atmospheric Administration (NOAA) introduced the concept of oxygen-enriched air diving. They created a breathing gas mix with 32% oxygen calling it NOAA Nitrox 1. <\/p>\n\n\n\n This mix allowed a maximum operating depth of 130 feet (ca. 40 m) and a maximum oxygen partial pressure of 1.6 atmospheres absolute (ATA), also noted as PO2 of 1.6. <\/p>\n\n\n\n The maximum oxygen partial pressure of 1.6 atmospheres absolute (ATA) was considered the highest partial pressure that would be safe before the possible onset of CNS toxicity symptoms. <\/p>\n\n\n\n Diving on 21% air, this level would not be reached until about 220 feet (ca. 67 m), however, on Nitrox I it was reached at 130 feet (ca. 40 m). As we increase the oxygen content of the breathing gas, the depth becomes shallower. <\/p>\n\n\n\n When EAN became more wide spread in recreational diving, the PO2 of 1.4 became the safe level for planning the dives. Avoiding Central Nervous System (CNS) Oxygen Toxicity is simply a matter of keeping our PO2 below 1.4.<\/p>\n\n\n\n CNS toxicity symptoms can be remembered using the acronym CON-VENTID<\/em><\/strong>.<\/p>\n\n\n\n The breathing gases EAN-32 and EAN-36 are the most commonly used and Nitrox dive tables will show the Maximum Operating Depth for these:<\/p>\n\n\n\n However, you will often find other percentages when you test your dive tanks. In those cases, you may have to calculate the MOD yourself.<\/p>\n\n\n\n The MOD formula for feet in salt water looks more intimidating than it really is.<\/p>\n\n\n\n The MOD (feet) is 33 feet x [(PO2\/FO2)-1]. PO2 is the desired partial pressure in oxygen and the FO2 is the decimal value of the fraction of oxygen in the mixture. For example, if a tank contains 32% oxygen and the maximum PO2 is 1.4 ATA, the MOD (feet) is 33 feet x [(1.4 \/ 0.32) – 1] = 111 feet.<\/p>\n\n\n\n To obtain a MOD in meters, we just use 10 meters instead of 33 feet. For example, if a gas contains 32% oxygen and the maximum PO2 is 1.4 bar, the MOD (meters) is 10 meters x [(1.4 \/ 0.32) – 1] = 33.7 meters.<\/p>\n\n\n\n It is standard procedure for a diver to independently verify the oxygen content of their cylinders, calculate the MOD, record their findings in a log and to mark the cylinder with the MOD. <\/p>\n\n\n\n When using a dive computer, the diver will enter the oxygen percentage into the computer before stating the dive.<\/p>\n\n\n\n The talk of oxygen toxicity may put you off EAN at first. However, look past that. When you first started to learn to dive, DCS was a major concern. It did not take you long to understand it and learn how to control the risk. <\/p>\n\n\n\n When diving with an EAN mix, we need to consider the risk of oxygen toxicity. However, with training, you will see that it is a risk that is clearly understood and easy to manage.<\/p>\n\n\n\n A few extra minutes of preparation can lead to a much longer dive.<\/p>\n\n\n\n If you have any questions or comments, feel free to add them.<\/em><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":" How deep can you go with Enriched Air Nitrox (EAN) is often misunderstood by those who have yet to be<\/p>\n","protected":false},"author":1,"featured_media":2175,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","footnotes":""},"categories":[15],"tags":[18],"acf":[],"yoast_head":"\nEnriched Air Nitrox Depth Limits and Oxygen Toxicity.<\/h2>\n\n\n\n
![\"scuba](\"https:\/\/divingcorner.com\/wp-content\/uploads\/divers-deep-1024x683.webp)
<\/picture><\/figure>\n\n\n\nAvoiding Central Nervous System (CNS) Oxygen Toxicity<\/h2>\n\n\n\n
![\"deep](\"https:\/\/divingcorner.com\/wp-content\/uploads\/diver-rope-1024x683.webp)
<\/picture><\/figure>\n\n\n\nCalculating Enriched Air Nitrox Depth Limits<\/h2>\n\n\n\n
![\"diver](\"https:\/\/divingcorner.com\/wp-content\/uploads\/diver-blowing-bubbles-1-1024x683.webp)
<\/picture><\/figure>\n\n\n\nOxygen Percentage<\/th> Maximum Operating Depth (ft.)<\/th> Contingency Depth (ft.)<\/th><\/tr><\/thead> 21%<\/td> 186<\/td> 218<\/td><\/tr> 22%<\/td> 177<\/td> 207<\/td><\/tr> 23%<\/td> 167<\/td> 196<\/td><\/tr> 24%<\/td> 159<\/td> 187<\/td><\/tr> 25%<\/td> 151<\/td> 178<\/td><\/tr> 26%<\/td> 144<\/td> 170<\/td><\/tr> 27%<\/td> 138<\/td> 162<\/td><\/tr> 28%<\/td> 131<\/td> 155<\/td><\/tr> 29%<\/td> 126<\/td> 149<\/td><\/tr> 30%<\/td> 121<\/td> 143<\/td><\/tr> 31%<\/td> 116<\/td> 137<\/td><\/tr> 32%<\/td> 111<\/td> 132<\/td><\/tr> 33%<\/td> 107<\/td> 127<\/td><\/tr> 34%<\/td> 102<\/td> 122<\/td><\/tr> 35%<\/td> 99<\/td> 117<\/td><\/tr> 36%<\/td> 95<\/td> 113<\/td><\/tr> 37%<\/td> 91<\/td> 109<\/td><\/tr> 38%<\/td> 88<\/td> 105<\/td><\/tr> 39%<\/td> 85<\/td> 102<\/td><\/tr> 40%<\/td> 82<\/td> 99<\/td><\/tr> 41%<\/td> 79<\/td> 95<\/td><\/tr> 42%<\/td> 76<\/td> 92<\/td><\/tr> 43%<\/td> 74<\/td> 89<\/td><\/tr> 44%<\/td> 72<\/td> 87<\/td><\/tr> 45%<\/td> 69<\/td> 84<\/td><\/tr> 46%<\/td> 67<\/td> 81<\/td><\/tr> 47%<\/td> 65<\/td> 79<\/td><\/tr> 48%<\/td> 63<\/td> 77<\/td><\/tr> 49%<\/td> 61<\/td> 74<\/td><\/tr> 50%<\/td> 59<\/td> 72<\/td><\/tr><\/tbody><\/table> It Nitrox Worth The Extra Step<\/h2>\n\n\n\n