Film Photography: Is Your Darkroom Safe?

Having a your own darkroom can be fun and profitable. But watch out for the hazards.

I’ve had a darkroom of one sort or another since I was in college when my roommate and I turned our dorm room into a portrait studio and our walk-in closet, a black and white lab. Usually located in a laundry room, bathroom, or large closets, all my darkrooms have had one thing in common: little or no ventilation.

About 9 years ago, I began to connect the darkroom with health problems I was having. And now that I know the dangers of photographic chemicals and their fumes, I am surprised and fortunate that I haven’t had even more severe problems. See setting up a home darkroom


The realization that I was slowly being poisoned finally came to me after I set up a darkroom in the laundry room of my house. While it was much larger than the closets and bathrooms I had used before this time, I noticed that I was only able to work for about 15 minutes at a time and then I would always begin to feel anxious and have trouble concentrating.

It was only after I had an assistant helping me that I fully realized the severity of the situation. After about 10 minutes working over the sink she complained of trouble breathing. After about 15 minutes she said, “We’ve got to get out of here. We’re being poisoned!”

And she was right. The air was full of sulfur dioxide gas. And needless to say, sulfur dioxide gas is not healthy to be breathing.

That incident woke me up to the need to ventilate my darkroom. I installed a large fan and the work space became a much more comfortable place to work. It also cured the aching, irritability and flu-like symptoms that I had after a long session of printing.

When I built my studio, I was able to build the darkroom of my dreams, a large airy space with a large sink, running water, and good ventilating fan. But my experience with sulfur dioxide gas poisoning was not yet over.

The darkroom is large enough for 3 people to work at a time. So I began to offer small classes on darkroom skills through our local arts council. One of the students was a respected artist noted for multi-media collages. She wanted to take the darkroom class so she could learn how to print photos on various materials to be part of her artwork.

When it was her turn to work in the lab, she brought various materials, rocks, pieces of cement, glass and copper foil that she had previously coated with Liquid Light, a product consisting of a liquid gelatin emulsion, that allows you to print on about anything. Another student, a police officer, was enlisted to help in this project as he was also interested in the Liquid Light process.

We had interesting results with all of the materials although the copper was a little disappointing, because it did not maintain its shiny color. We decided to print all of the copper sheets anyway, just to use them up. Before we were done we began to feel a tightness in our throats. The ventilation fan was going but obviously something was happening. We stopped what we were doing, threw open the door and dumped all of the chemicals.

The next day, Dave, the policeman, called and asked if I was feeling all right. He said he was feeling rotten like he had the flu and he was having trouble concentrating, which was not especially healthy given the work he does. I admitted I was feeling the same way and that it could have been the incident in the darkroom causing our symptoms.

I use Ilford chemicals and remember seeing their emergency number displayed prominently on every bottle of Ilford chemicals. I called the number and talked to a receptionist who took my information and said someone would get back to me. Yeah, right, I thought. Within 15 minutes, however, a doctor from Ilford was on the phone. After I explained our situation and the symptoms, he said that it sounded like a classic case of sulfur dioxide poisoning.

He explained that this was one of the most common problems for workers in black and white darkrooms, that the characteristic smell of a darkroom comes in part from the gas. He told me that the symptoms would go away to 24 to 48 hours, but that our reaction to the gas was cumulative and that over time it would take lower and lower doses of the gas to cause the same reaction.

He passed on some valuable tips to help prevent further problems. First turn on the ventilating fan an hour or more before you start working. This will remove any gas that has managed to enter the air since the last time you worked. After your work session leave the fan on for several hours. Also make sure you clean up well after you work. Don’t leave chemicals in trays or spills on or in your work space, as these will release gases as they evaporate and/or react to oxygen in the air.

Also because I had a long history of exposure to the gas, he suggested purchasing a mask, as it was likely that any amount of the gas I was exposed to would cause symptoms. He suggested that I get one as soon as possible. I bought mine from Lab Safety Supply. It is a disposable acid gas respirator made by 3M. It costs about $17.00 and you throw it away when the cartridge is expended. Other choices, of course, are available.

I thought that would be the end of Ilford’s involvement, but I was wrong. Two hours later an engineer called and asked me to tell him exactly what we had done during our class session. I told him about all of the materials we had coated, printed and developed.

The common way sulfur dioxide gas is generated in the darkroom, he said, is carryover from the developer into the fixer. Mixing of the two generates a lot of gas. I explained that we used fresh stop bath solution and I didn’t think we had carryover.

He thought a moment and then said, “I’ll bet it was to copper! It must have caused a reaction that generated the gas.” That made sense, I thought, as metals are often catalysts in chemical reactions.

“Hey, Mike,” he said after a few moments. “Do me a favor. Don’t do this again.” We both laughed. I didn’t need convincing.

About two days later he called back. “I repeated your experiment. I used a penny. You wouldn’t believe the amount of sulfur dioxide given off when the penny hit the fixer! Just thought you’d like to know. And, hey, we’re going to include this in our next tech report, warning people about using copper.”

About a week later he called again. “Hey, Mike. Just called to see if you recovered OK. And to make sure you’re not playing with copper again!”

Needless to say, I am an Ilford fan. I never expected such prompt and thorough attention. Sure, some will say they were just covering their bases to avoid a law suit. Maybe that was a part of it, but I was still impressed.

Susan D Shaw and Monora Rossol have written a book called “Overexposure: Health Hazards in Photography.” (Allworth Press, 1991) It’s a book well worth having if you have a darkroom or are considering building one.

Here are some safety tips they recommend:

~ Access to running water. Running water should be readily available, not only for washing prints, but cleaning up after your work session. Wash your hands and work area thoroughly when you are finished. Running water is also necessary in case of contamination to one’s eyes.

~ Easy access to outside air for ventilation. Rooms in ordinary houses or apartments are usually not sufficiently ventilated for photographic processes. Installation of fans can solve this problem.
~ Sufficient distance from living areas. If small children are present or if the living and working areas cannot be totally separated, it is not advisable to work at home. It is easy to contaminate a living space by tracking powders or allowing gases to escape from your work area. Also be sure not to ventilate your darkroom into the vicinity of someone else’s living area, by exhausting into basements, crawl spaces or attics.
~ Access to waste disposal. Some communities have large fines for dumping photo chemicals into the sewer. Check out local codes before building your darkroom. Some chemicals can cause septic systems to stop working. Check to be sure the processes you use will not cause serious problems if you use a local septic system.
~ Store chemicals properly. Keep out of reach of children. Label and date your bottles. Containers should be non-breakable. Watch some plastic containers. My hypo clearing agent ate through a plastic milk bottle it was stored in. Eliminate all chemicals in containers with incomplete or missing labels.
~ Electrical Safety. Darkrooms are wet places. Outlets should have ground fault interrupters installed. Make sure your circuits are of sufficient size to handle the load of your darkroom equipment.
~ Hygiene and housekeeping. Don’t eat, drink, smoke, apply makeup or perform other personal hygiene procedures in the darkroom. Hand to mouth and hand to eye contamination can occur. Dust and powders can contaminate food and drink. Smoking is especially dangerous. Dust and vapors can react with the cigarette and burn and then be inhaled. Wear aprons or other protective clothing and leave them in the darkroom. Wash them frequently, but not with other clothing.

There is much more information to help you plan your darkroom in this book and others. Make sure you keep yourself, your family and workers safe.
Safety Equipment Sources. There are several safety equipment directories available. One is Best’s Safety Directory. Check for it at your local library.

by Michael Fulks
All text and photos: © Michael Fulks. All Rights Reserved.

All written content (and most images) in these articles are copyrighted by the authors. Copyrighted material from Apogee Photo Mag should not be used elsewhere without seeking the authors permission.

1 Comment on Film Photography: Is Your Darkroom Safe?

  1. I’ve been working with liquid photographic emulsion for several years, on many different materials and surfaces, including computer motherboards. When stripped of their components, and grit-blasted or sanded down, the intricate layer of copper circuitry on the board is revealed. I’ve put motherboards like this through black and white darkroom chemistry numerous times but I cannot recall a noticeable release of sulphur dioxide or experiencing the symptoms you describe.

    Further to reading your story however, I decided to contact Ilford myself, to request information concerning potential health and safety risks of bringing copper into contact with darkroom chemistry. Their response (March 2016) was as follows:

    “I have asked one of our chemists about this and he has said that this should be avoided from the effectiveness point of view. The developer may be OK with copper as the higher pH would tend to protect it but on the other hand we know that small quantities of metal ions can kill developers. Unfortunately, the acidic fix and stop would probably corrode the copper, in fix forming copper sulphide and in stop bath copper citrate etc. I am not aware of any further H&S risks from the formation of these copper salts. At least the same precautions should be used as indicated by our chemistry MSDS’s. Perhaps you should consult
    with someone in your Chemistry department and have them look at what you intend to do and advise further.”

    A very informative and useful response I’m sure you’ll agree – but no mention of sulphur dioxide.

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