Fixer then makes the image permanent and light-resistant by dissolving any remaining silver halide salts. Developer solutions and powders are often highly alkaline and are moderately to highly toxic. They are also sources of the most common health problems in photography; skin disorders and allergies.
Color darkroom chemicals are more toxic than black & white chemicals for you and the environment so always take precautions like wearing gloves, an apron, protective eyewear, and a mask when using color development chemistry – especially when mixing and using the open tray method of development.
Potassium dichromate and potassium chlorochromate are probable human carcinogens, and can cause skin allergies and ulceration. Potassium chlorochromate can release highly toxic chlorine gas if heated or if acid is added.
With some developers, convulsions also can occur. Para-phenylene diamine and some of its derivatives are highly toxic by skin contact, inhalation, and ingestion. They cause very severe skin allergies and can be absorbed through the skin.
The fixing agent, sodium thiosulfate, along with the preservative, sodium bisulfite, can break down (decompose) to form sulfur dioxide gas, which can damage the lungs and provoke asthma attacks.
Fixation is commonly achieved by treating the film or paper with a solution of thiosulfate salt. Popular salts are sodium thiosulfate—commonly called hypo—and ammonium thiosulfate—commonly used in modern rapid fixer formulae.
Photographic chemicals are not hazardous when used correctly and when basic rules of common sense are observed. Do not eat, drink, or smoke in areas where chemicals are handled or used. Keep all photo processing chemicals out of reach of children and animals.
The chemicals inside a Polaroid picture, or any other instant film, are not harmful in limited amounts and are most harmful if ingested. If you get the chemicals from inside Polaroid film on your hands, immediately wash your hands with warm soap and water.
Is Developing Film at Home Dangerous? Even though chemicals are used in the developing process, developing film at home is not dangerous. The chemicals typically used for black & white are classified as toxic but only when consumed or in come into contact with your eyes or skin.
Developer sometimes contains Hydrochinone which is an allergen. Skin contact should be avoided for that reason, to remain able to enjoy the hobby (or handling offset inks) for a very long time. You should also wash a hand that you dunked into stop bath or fixer to not spoil your developer.
photographic development process
The fixing bath contains a chemical (sodium or ammonium thiosulfate) that converts the silver halide into soluble, complex silver salts that dissolve in the fixer. During this process the film loses its original silver halide milkiness overlaying the image and becomes clear.
The presence of developer in fixer affects its pH (acidity/alkalinity) - it does not affect the fixer's capacity to fix film (dissolve undeveloped silver salts). This capacity depends on the presence of dissolved silver salts - beyond a certain point, the fixer cannot dissolve any more and so cannot fix your film.
Do not eat, drink or smoke in the darkroom. The darkroom should be well ventilated. Wear appropriate protective equipment whenever possible, such as gloves, goggles, etc. Always wash hands with soap and warm water after working with chemicals.
You can safely dispose of them into a sewer system (even a septic system in reasonable amounts). Notwithstanding, you should check your local regulations. Fixer with lots of dissolved silver in it is the real problem (unused fixer is fairly benign and you can dispose of it in the sewer system).
You don't need a respirator but you do need good ventilation and a good extractor fan preferably close to the wet side of the darkroom. In the past I've had to use an air-line respirator but then we were spraying emulsions and chemistry but that's grosss overkill as is a respirator for normal uses.
Black and white film developing chemicals are NOT dangerous, as long as you take simple, common sense precautions. Maybe some people are just more sensitive to chemicals, and in that case they might need to be extra careful. But in general, photo chemicals are not that toxic.
No. Even caffenol and Vitamin C are chemicals. The film is made of chemicals. The camera that shot the film is made of chemicals.
Common chemicals used as developing agents are hydroquinone, phenidone, and dimezone. The developing mix must have high acidity, so chemicals such as sodium carbonate or sodium hydroxide are often added to the mix.
Do not put this film in the mouth. Take special care to keep this film away from small children or pets. Each film sheet contains a caustic processing fluid. Never cut, tear or punch holes in unused films.
The three basic chemicals are (1) Developer (2) Stop Bath and (3) Fixer. Mix these with the appropriate amount of water and store them in your bottles. Photographic Paper. Photographic paper is sensitive to light and should be handled only in a darkroom with the correct safelight.
Most photographs that were taken long ago can't be thrown in the regular trash bin. Photo paper contains plastics and metals, making them unsafe when mixed with other solid waste. These chemicals are also considered toxic to the environment.
The Ammonium thiosulphate has the chemical formula: (NH4)2S2O3. It is used in modern photographic fixer. Photographic processing is the chemical means by which photographic film or paper is treated after exposure to produce a negative or positive image.
Many photographic chemicals use non-biodegradable compounds, such as EDTA, DTPA, NTA and borate. EDTA, DTPA, and NTA are very often used as chelating agents in all processing solutions, particularly in developers and washing aid solutions.
The thiosulfate fixer makes a compound that is soluble in water, so the leftover silver halides rinse off in the water. The fixer itself also must be removed because it itself can degrade the image. It decomposes to form acid that reacts with the silver to form silver sulfide.