OK--when I was doing small sheets and rolls in a tank, I'd occassionally get a little ozone type whiff.....not much and not long. now I"m doing 11x14 reversals and tray-bleaching---lemme tell you...there's a HUGE reaction area with this.....so now...the reaction fumes are more "noticable" .... and it smells different now....maybe it's the different bleach I"m using..I was using kodak dichromate motion picture bleach liquid concentrate--just ran out...now I'm using dichromate mixed with sodium bisulfate instead of sulphuric---SO---the smell is actually a mix of the ozon-y smell along with this other smell that smell like this old agfa paper I have--NOW---what are the possible reaction products of dicrromate bleaching of film--I know it should be just like ozone at the worst- but now I'm afraid I'm getting like welding gasses--chromic oxide stuff---is that possible? or am I maybe also smelling some of the acid too--this is the first time I'm using the "homebrew" bleach..... I've heard that the dichromate will react with the gelatain to harden it, so is there something coming out there? I'm only concerned if it's BAD stuff that can be getting evolved---it doesn't look like chromium getting evolved can be a concern--looking at the reaction, but...maybe it IS???? anybody know for sure what the OTHER byproducts are? I'm now just going to abaondon the tray bleaching for sure and do it all in tubes to keep the stuff more confined and away from me...besides the tubes agitate better.....hopefully the tubes will considerably reduce the fume problem BUT STILL!!!!! any idea if chromium fumes are a concern, or is that just not very likely from a chemistry perspective?