NOAA's chart for oxygen pressure time limits shows 180 min as the daily limit for a 1.4 exposure. Even at six dives a day, which is more than most liveaboards offer, a diver on 32% would have to spend 30 minutes per dive at 1.4. That's 30 min at 111', just do-able with NDC limits on this chart http://www.ndc.noaa.gov/pdfs/nitrox32.pdf. On 36%, 30 min at 95' is and that's easily do-able according to this table: Nitrox 36% Water Proof Dive Table (NT21) which gives the 36% NDC limit as 40 min.
At only 5 dives a day, say off a liveaboard, one would have to spend 36 min per dive at depth, only do-able on 36% without requiring decompression stop(s) according to the above tables, and most liveaboards I've been on that offer nitrox usually only pump 32%. That's why people don't get into trouble on liveaboards.
If I went to Bonaire and dove the six dives per day with an AL80 with an SAC of .5, I should be able to do 30 min at 111' and have 500 psi to spare, assuming a good fill and not counting ascent/descent time. Because ascent/descent time is part of the dive, one would need an SAC better than .5 and/or a larger tank. However, my NDC calculations were for single dives. Obviously residual nitrogen would restrict the NDC time of subsequent dives, so that 30 min at 111' isn't possible for 6 dives in a day without incurring deco obligations. Exactly how much deco, and how much air it would take to accomplish it, I leave to someone else to calculate.
Short answer: Nothing to worry about unless exceeding 6 dives a day and doing some deco, or using custom mixes of > 36% and still doing a lot of diving, so not at all a likely concern for the casual nitrox diver.
At only 5 dives a day, say off a liveaboard, one would have to spend 36 min per dive at depth, only do-able on 36% without requiring decompression stop(s) according to the above tables, and most liveaboards I've been on that offer nitrox usually only pump 32%. That's why people don't get into trouble on liveaboards.
If I went to Bonaire and dove the six dives per day with an AL80 with an SAC of .5, I should be able to do 30 min at 111' and have 500 psi to spare, assuming a good fill and not counting ascent/descent time. Because ascent/descent time is part of the dive, one would need an SAC better than .5 and/or a larger tank. However, my NDC calculations were for single dives. Obviously residual nitrogen would restrict the NDC time of subsequent dives, so that 30 min at 111' isn't possible for 6 dives in a day without incurring deco obligations. Exactly how much deco, and how much air it would take to accomplish it, I leave to someone else to calculate.
Short answer: Nothing to worry about unless exceeding 6 dives a day and doing some deco, or using custom mixes of > 36% and still doing a lot of diving, so not at all a likely concern for the casual nitrox diver.