Apparently the ventilation is really good but my symptoms after processing so many prints say otherwise. I was processing on the other side of the room (vents are by the sink) I dev and fix at the counter (6 feet from the array of vent hoods). As another posted above - this will cause the fumes to go right past my head. If this is the case, I'm still interested in a mask.
Well the sink area is for the wet processing, so move to the sink where the extractor fans are.
Ok. Will do. If I still want a respirator, which filter?
http://sprintsystems.com/msds2011/MSDS_FIX_2010.pdf indicates a respirator should be used if there is a sensitivity. I just don't know which of 3M's filters is sufficient.
I have allergies, to lots of things and they cause allergic asthma. I don't use a special ventilation or respiratory mask, I only use dust mask when mixing chemicals. I said this so you know I have sensitivity and which chemicals irritate the most for me. But I had no problems in the dark room ever. You should see a doctor, in my opinion. You should check if you are suffering from allergies, or other respiratory problems.
Anyway, be careful with the Ferric amonium citrate and tartaric acid in powder form. Even though I like the smell of tartaric acid, those powders are very fine (I hope that is the right term) and 'citrate' as you can imagine irritates the most. It is like sniffing black pepper, sneezing and mildly uncomfortable in the nose. Citric acid I used was in crystal form, I guess yours might be same. If that is in powder form be careful about that too. Not that any of these chemicals are very harmful but as I said my allergies are triggered if I am not careful with these, so I guess these are mildly irritant. When preparing ID-11 use a mask when mixing the powder, it is also very fine powder and I feel uncomfortable when I prepare that. I had no problems with any of the chemicals in your list. Don't forget to respect the silver nitrate :)
But I believe after you mix the chemicals into solutions they won't be too much trouble. You will use plain hypo (I gather you are going to do VanDyke), and it is not as irritant as the rapid fixers containing extra sulfates and acid. Sodium bisulfate and metabisulfate really irritated me when I used it for other chemical preparations. They smell nasty and they gave a slight burning sensation in the nose.
And warning for the future, considering that you are sensitive to chemicals, be very very careful with bichromates/dichromates they are the most harmful chemicals in powder form, relatively safe in solutions. I have severe allergies to chrome, but I can mix and use it safely. No problems so far (no dermatitis). Not to mention I use gloves and mask.
I hope it all goes well.
Thanks. Yes, I didn't go to the doctor, but I should have. The exposure to the chemicals left me completely debilitated for a week or so, severe nausea for about 4 days, and a really nasty sore throat for about a month. I was printing with very large trays (large prints) which, I assume, would give off more vapor than a smaller tray. I would feel more comfortable to wear a respirator at least when processing film (in trays). I don't think I will be comfortable again without one (Nosemaphobia).
A respirator is not the answer, it's asking for trouble.
I used to be a research chemist and toxicologist until I went commercial. Here are a couple of old incidents from my time as the hot-line guy for Eastman Chemicals:
A darkroom worker complains of headaches, dizziness, and general malaise while working in a well ventilated darkroom. He blames the "fumes" from the "chemicals".
When I check his work space I find that the guy is doing 5 hour darkroom sessions while wearing a double cartridge (dust and vapour) face mask. He's got a deep fear of chemicals but what's getting him is ordinary anoxia and re-breathed carbon dioxide because he's not ventilating adequately.
An urgent call comes through from someone with metol allergy. The stuff is literally eating his hands even though he is wearing surgical gloves. It turns out that the victim has latex allergy from the gloves and the metol is innocent. But the story has spread to every darkroom in town and it takes ages to hose it all down.
Sometimes fear of chemicals can lead people into danger. Sometimes chemical sensitivity is so extreme that only an actively inflated positive pressure biohazard suit is mandatory . Any darkroom design, any chemical process, that requires respirators and gloves for worker survival is absolutely not worth going into at any price. There is an unbreakable principle of workplace safety at stake here.
I second Maris's comments about the filter causing problems as well. Where I used to work, they made us wear respirators when making slide preps of hairs using a toluene based media. Despite having it professionally fitted, I had problems breathing with it. I have asthma and I've heard this is common with masks.
If you insist on using one, one of the ones covering acids is a better bet than the one for organics you linked, imo. If you mixed anything from a powder that day, that is likely the cause as well. Powders are much more easily inhaled in quantities that will cause problems (the main reason I use things that come as liquids). A particulate filter should be fine for that. You also need to be careful to make sure you don't get a cloud of powder flying up when you dump it into the container.
If you do your tray work by time rather than by watching (better for consistency), you only need to be an arm's length from them to agitate the tray. Standing over them won't be good for the lungs or the back.
There are schools that still have darkrooms?