ventilation

Chriscrawfordphoto said:
I disagree, I got sick from fumes as have others I have known. Developers are based on extremely nasty organic chemicals based on benzene. They can evaporate into the air, you can breathe them, and they will make you sick with long term exposure.
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Dear Chris,

Highly disputable. The benzene ring, once incorporated in heavier molecules such as most developers, is likely to have a negligible vapour pressure. Dust from poor 'housekeeping' (dried spillages) is a FAR greater risk than evaporation of developer; one might almost say, infinitely greater.

As far as I recall, quite a lot of perfectly natural food flavours incorporate at least one benzene ring. I'm reasonably confident that all this is reliable chemistry, but perhaps Marty (Freakscene) could confirm whether I am right or wrong.

Cheers,

R.
 
I'm not Marty, but a lot of biochemicals have a "benzene ring" in them. The three main pain relievers, aspirin, ibuprofen and tylenol all have it. Tylenol by the way, is almost the same chemical as rodinal, but rodinal is poisonous. It doesn't take much structural difference to change the properties of a chemical.

Some people can develop hyper-sensitivity to particular chemicals, and this could account for folks who are made ill by even microscopic quantities of a particular chemical.
 
Chris101 said:
I'm not Marty, but a lot of biochemicals have a "benzene ring" in them. The three main pain relievers, aspirin, ibuprofen and tylenol all have it. Tylenol by the way, is almost the same chemical as rodinal, but rodinal is poisonous. It doesn't take much structural difference to change the properties of a chemical.

Some people can develop hyper-sensitivity to particular chemicals, and this could account for folks who are made ill by even microscopic quantities of a particular chemical.
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Dear Chris,

You are of course absolutely right. I should have cast my net wider. Thanks.

Cheers,

R.
 
I think that the proper thing to do is to make sure that you have fresh air coming in the darkroom ( via light-tight louvers or something else ) and a fan to suck out the fumes. If you don't have any fresh air coming in, then the fan won't be as effective at sucking out the fumes.
 
so i've set up my enlarger and stuff. i mixed up my chemistry tonight (in my well ventilated basement), and i can honestly say - if that's the worst of it, i don't think super ventilation is necessary. its a bit foul smelling, but definitely not "bad" compared to sanding drywall, insulating, etc.

i realize i am not basing this on anything scientific, but reason would suggest that my own discomfort is nearly as valuable as the warning labels.

i am a lawyer by trade, so i understand the need to have alarming labels on the packaging. however, most of these chemicals simply say "do not drink", etc. i suspect there are far more noxious chemicals in my house.
 
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Chris101 said:
I'm not Marty, but a lot of biochemicals have a "benzene ring" in them. The three main pain relievers, aspirin, ibuprofen and tylenol all have it. Tylenol by the way, is almost the same chemical as rodinal, but rodinal is poisonous. It doesn't take much structural difference to change the properties of a chemical.

Some people can develop hyper-sensitivity to particular chemicals, and this could account for folks who are made ill by even microscopic quantities of a particular chemical.
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Tylenol/acetaminophen/paracetemol overdose is (typically in combination with alcohol) the leading cause of acute liver failure in the United States. Not exactly the poster child for a benign toxicity profile, that one.
 
semilog said:
Tylenol/acetaminophen/paracetemol overdose is (typically in combination with alcohol) the leading cause of acute liver failure in the United States. Not exactly the poster child for a benign toxicity profile, that one.
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No, it isn't a psoter child for safety, but risk is relative.

More people die in car accidents or from long-term effects of exposure to fuel, both burnt and unburnt, than die of paracetamol induced liver failure. But you never see extraction and PPE used at petrol/gas stations either, or warnings beside busy roads. Petrol contains hydrcarbons vastly more toxic than anything in normal B&W photo chemicals.

Read the Material Safety Data Sheet (MSDS) for the products you use and understand the manufacturers directions. Remember that you can get acutely ill with no long-term effects and suffer severe long term effects or die from things you do not even know you are being exposed to. Make personal choices about the risk and manage it with that in mind.

Marty
 
semilog said:
Tylenol/acetaminophen/paracetemol overdose is (typically in combination with alcohol) the leading cause of acute liver failure in the United States. Not exactly the poster child for a benign toxicity profile, that one.
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If used in moderation both Tylenol and alcohol can be used safely by most people. I wouldn't combine the two under any circumstances though.

A problem with Tylenol is that it is combined with so many other medications though. Most cold remedies have it, as do many high strength, narcotic based pain relievers such as Vicodin and Percocet.
 
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Having been spending the weekend being "schooled" in the chemicals necessary to maintain an average swimming pool in a typical US suburb residential, I can speak now from experience that darkroom chemicals looks benign by comparison. 😀
 
shadowfox said:
Having been spending the weekend being "schooled" in the chemicals necessary to maintain an average swimming pool in a typical US suburb residential, I can speak now from experience that darkroom chemicals looks benign by comparison. 😀
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Elegant, Will!

Or as I wrote recently, "When people stop cleaning their toilets, I'll stop B+W printing."

Cheers,

R.
 
Peope react differently to different chemicals. I can't use bleach -- Clorox, etc. -- because, even in dilution, my eyes sting and redden. No matter how effective the ventilation.

My reaction to the odors associated with a darkroom is the reason I don't have one, in addition to space issues. I mixed up a batch of stuff in the bathoom I was planning to use, and closed the door.(Adding more ventilation is a non-starter.) Fifteen munutes later I knew that wasn't for me. Kitchen sink processing isn't an issue, I assume because of the much smaller volumes involved.
 
Get a "black out" louvre panel for the door and run a 4" flexible hose (similar to a dryer hose) from above the sink and put a fan in it. Cut a hole to handle the hose - either vent it outside or use that fireplace flue. You dont need that much airflow as the room is small - but printing can be exhausting if you dont have clean air coming in.
Also make a rule - not to mix chemicals in the darkroom, the dust from powdered chemistry lingers a long time. Just get some substantial beakers to handle the chemistry.
Most reactions to darkroom chemicals seems to be to Sodium Sulphite and Metol. Can give an irritating rash! Stuff like stop-bath and hypo mainly smells bad!
If you can find a quiet enough fan for the ducting hose - put a rheostat on it - run it at slow speed - before you start a session and crank it up while working in there. You will be surprised at how long time you will spend in there when you are using it.
Dust can be problem if you pull air in from the rest of the basement - you can stop some of it by stick a furnace filter over the black our louvre panel (duct tape works fine).
 
A lot of very sensible and sane perspective here that I'm in agreement with (thumbs up especially to Freakscene, Shadowfox, Roger, Tom). Excercise care, read and understand the MSDS's for your chemistry, don't live in fear.

And be especially careful with toners and the related chemistry (selenium, ferricyanide, etc.). They really can be dangerous, and should not be used without gloves, apron, eye protection and good ventilation.
 
Lots of sensible advice in this thread. Many good suggestions.

I have been doing B&W chemistry on-and-off since 1985, and have yet to notice any ill effects. In the past year I have been doing my own B&W in my basement about 2x per week, in a spare bathroom. No health issues.

Back in the late 1980's, I was experimenting with silk-screening. I was running exposed half-tones onto screens. To leave the negative image on the screen, we had to rinse and prep the framed screen with xylene. This was in the days before MSDS's or any common sense about such things. I remember pouring xylene over the frames without ventilation. After a minute or so, I got light-headed and the entire surface of my body broke out in alien-like red bumps.

Needless to say, I quit silk-screening after that incident. Never did it again. I figured that making fun T-shirts wasn't worth liver failure or bone marrow cancer.

Regarding the OP's topic: I agree with other posts that it depends on your own individual sensitivities and methodology. I live in a newer house with a conventional bathroom fan. That's all the ventilation I use for my developing.

In my (uneducated) opinion, B&W is relatively benign. That isn't to say the chems shouldn't be treated respectfully.

I've experimented in doing my own C-41 at home, and let me tell you -- that seems much worse in terms of harsh chemistry. Harsher by orders of magnitude. The blix smells like raw evil itself and looks like dragon's blood (as a visual example ... I've never actually seen dragon's blood!)

I use HUGE amounts of ventilation when I do C-41 or E-6 at home. Innately, something tells me these chemicals are far worse than plain-old D-76. I wear industrial gloves, run fans, open windows, and limit my exposure as much as possible. I even bought a respirator, but haven't used it yet -- although I should.

I have read about guys doing C-41 in their kitchen sink with their bare hands and I think that is unadulterated foolishness.

Anyhow, best of luck setting up your darkroom! Yes, there are risks, but with a few sensible precautions you'll be 100% fine.
 
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At last something I can help with! I'm a building services engineer by profession and looking at Chapter 22 of the 2011 edtion of the ASHRAE (American Society of Heating, Air-conditioning and Refrigeration Engineers) Handbook 'HVAC Applications' (HVAC = Heating, Ventilation and Air Condtioning) the recommendation from their Standard 62.1 (Table 6-4) (summarized) is that air should be exhaust at a rate of 5 litres/second per square metre of floor area (I work in the UK and we have used metric SI units in the building/engineering industry since the start of 1970 - there are plenty of metric to imperial conversion tools available on line for those working in imperial). if you are supplying air I suggest the supply rate is say 90% of the exhaust rate so that air is always being drawn out. Changing tack a little, UK Building Regulations for enclosed rooms such as toilets and bathrooms (without windows to outside as found in flats and hotels etc.) require ventilation at the rate of three air changes per hour - I tend to design 'busy' toilets at say eight to ten air changes and for a solo-occupation flat perhaps at six to eight air changes per hour. I would do some calculations and design for the greater of these suggested volumes. Even if the chemicals weren't toxic/didn't smell you would need fresh air just to be able to concentrate. I hope this helps. Let us know how you get on.

Regards

Andrew More
 
Anyone know if people like Kodak and Fuji have released any long-term data about this? E.g., what's the cancer rate, etc., in employees a decade or two after exposure stops?
 
The material Safety Data Sheets (MSDSs) should be read but will be of limited value in determining how much ventilation you need unless you work in a commercial lab and the air quality is measured.

Aside from saying move to fresh air if symptomatic, the MSDSs provide OSHA Permissible Exposure Limits (PELs) and ACGIH (American Conference of Governmental Industrial Hygienists) Threshold Limit Values (TLVs) in parts per million in air PELs are time-weighted average concentrations not to be exceeded during any 8-hour work shift of a 40-hour work week. TLVs are guidance values that should not be exceeded. There are different values for solids and vapors.

So there is some quantitiative basis for determining exposure and ventilation needs, but as a practical matter, just provide some ventilation, maybe using a ventilation fan that can provide so many air changes per hour, as mentioned by a previous poster.
 
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