Both the State and Federal governments have regulations concerning the handling and disposal of photochemicals. These agencies are the Federal Environmental Protection Agency (EPA) and the State of Florida Department of Environmental Protection (DEP). Safety issues are addressed by the Occupational Safety and Health Act (OSHA) with compliance enforced by the State of Florida Division of Safety. This manual is a summary of the different types of photochemicals encountered in the darkroom with information on proper handling and safety procedures. This manual is not intended to replace the Material Safety Data Sheets (MSDS) as the source of information on photograhic chemicals. It is critical that the MSDS for each chemical be consulted to determine the specific hazard associated with that chemical.

There are many hazards associated with photographic materials. It is important that persons involved with photo processing, be aware of these hazards and that every effort is made to minimize the effects of these chemicals on the health of the community. For example, many photographic processes produce toxic gases. These gases may be released slowly from baths or stored chemicals as they age. In addition, these gases are usually generated at faster rates if the photochemicals are heated or if certain chemicals are mixed with acid. An effort to minimize the hazards associated with photographic chemicals begins with familiarity with the MSDSs and proper handling and disposal of these chemicals.

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. Developers are skin and eye irritants and many are strong allergic sensitizers. Some common ingredients in developers are hydroquinone and sodium sulfite.

• Hydroquinone can cause depigmentation and eye injury after five or more years of repeated exposure, it is also a mutagen.
• Sodium sulfite decomposes to produce sulfur dioxide (a toxic gas), when heated or allowed to stand for a long time in water or acid.

• Do not use para-phenylene diamine and diaminophenol hydrochloride (amidol) if at all possible.
• Replace other highly toxic developers such as catechin (catechol), chlorquinol, or pyrogallic acid (pyrogallol) with less toxic developers such as phenidone.
• If developer solution splashes on the skin or in the eyes, flush affected areas (15-20 minutes for eyes) immediately with water. Darkrooms should have access to an eyewash fountain and safety shower for such emergencies.
• When mixing powdered developers, ensure proper ventilation ( A fume hood is preferred).
• Ensure good ventilation of the darkroom. At least, 10 air changes per hour.
• Wear gloves and goggles.\
• Cover all solutions when not in use to prevent evaporation or release of toxic vapors and gases.

The acetic acid commonly found in stop baths can cause dermatitis and skin ulceration and can severely irritate the respiratory system. Contamination of the stop bath by developer components can increase inhalation hazards.

• Potassium chrome alum, sometimes used as a stop hardener, contains chromium and can cause skin and nasal irritation, ulceration and allergies.

• Purchase dilute solutions of acetic acid rather than concentrated ones whenever possible.
• Use a water rinse step between developer and stop bath to reduce the formation of sulfur dioxide gas.
• Discard used stop bath solutions that have become contaminated with developer.
• Always add acids to water. Remember "AAA" - "Always Add Acid"
• If a splash occurs, flush affected areas (15-20 minutes for eyes) immediately with water using an eyewash or safety shower.
• Cover all baths when not in use to prevent evaporation or release of toxic vapors and gases.
• Ensure good ventilation of the darkroom. At least, 10 air changes per hour.
• Wear gloves and goggles.

Fixer contains sodium thiosulfate, sodium sulfite and sodium bisulfite. It may also contain potassium aluminum sulfate as a hardener and boric acid as a buffer. Fixer solutions slowly release sulfur dioxide gas as they age. However, when these solutions are contaminated with acid from the stop bath, the gas sulfur dioxide is released at a more rapid rate.

• Sodium sulfite decomposes to produce sulfur dioxide, when heated or allowed to stand for a long time in water or acid.

• Sodium thiosulfate upon heating or a long-standing solution can also decompose to form highly toxic sulfur dioxide gas. Many asthmatics are particularly sensitive to sulfur dioxide.
• Sodium bisulfite also decomposes to form sulfur dioxide if it makes contact with boric acid or acetic acid.
• Boric acid is moderately toxic unless the skin is abraided or burned, then it can be highly toxic.

• Ensure good ventilation of the darkroom. At least, 10 air changes per hour.
• Wear gloves and goggles.
• If a splash occurs, flush affected areas (15-20 minutes for eyes) immediately with water using an eyewash or safety shower.
• Cover all solutions when not in use to prevent evaporation or release of toxic vapors and gases.

Many hypo eliminators are skin and respiratory irritants. Some are corrosive to skin, eyes, nose and throat.

• Ammonia (both vapor and liquids) is especially hazardous to eyes and to the mucous membranes of the respiratory system.
• Skin contact with iodine can cause a hypersensitivity reaction and skin burns. Iodine can also be highly irritating if the vapors are inhaled.

• Hypo eliminators are oxidizers and should be kept away from flammable or combustible substances.
• Wear gloves and goggles when dealing with persulfates and hypochlorite bleach solution.
• Keep away from sources of heat.
• Ensure good ventilation of the darkroom. At least, 10 air changes per hour.
• If a splash occurs, flush affected areas (15-20 minutes for eyes) immediately with water using an eyewash or safety shower.
• Cover all solutions when not in use to prevent evaporation or release of toxic vapors and gases.

-Un-used or concentrated solutions- send to EH&S for disposal.

Several intensifiers contain extremely hazardous components such as mercuric chloride, mercuric iodide, potassium cyanide, sodium cyanide and uranium nitrate. These compounds are all toxic by every route of exposure. The common two-component chrome intensifier contains potassium dichromate and hydrochloric acid. The separate components can cause burns, and the mixture produces chromic acid. Its vapors are very corrosive and over a long period of time can cause lung cancer.

• Do not heat or add acid to potassium chlorochromate. Potassium chlorochromate can release highly toxic chlorine gas, which can be fatal.
• Chromium intensifiers are probably the least toxic intensifier.
• Do not use mercury, cyanide or uranium intensifiers because of their high toxicity.

• Ensure good ventilation of the darkroom. At least, 10 air changes per hour.
• Wear gloves and goggles.
• If a splash occurs, flush affected areas (15-20 minutes for eyes) immediately with water using an eyewash or safety shower.
• Cover all solutions when not in use to prevent evaporation or release of toxic vapors and gases.

Disposal: -Save and send to EH&S for disposal.

The use of reducers involves the selective removal of silver from parts of the developed image. Reducers contain toxic chemicals such as alkali cyanide salts and carbon tetrachloride (both known or suspected human carcinogens).

• Do not heat or add acid to potassium ferricyanide because hydrogen cyanide gas will be released, which can be fatal.

• Do not use cyanide reducers because of their high toxicity.
• Farmer’s reducer is probably the safest reducer to use. Do not expose it to acid, UV light or heat.

• Ensure good ventilation of the darkroom. At least, 10 air changes per hour.
• Wear gloves and goggles.
• If a splash occurs, flush affected areas (15-20 minutes for eyes) immediately with water using an eyewash or safety shower.
• Cover all solutions when not in use to prevent evaporation or release of toxic vapors and gases.

Disposal: -Save and send to EH&S for disposal.

Toner usually involves the replacement of silver with another metal such as gold, selenium, uranium, lead, cobalt, platinum or iron.

• Uranium is a suspected human carcinogen.
• Lead is a suspected animal carcinogen.
• Gold and platinum salts are strong sensitizers.

These highly soluble toxic compounds are more dangerous since they can be readily absorbed in the body and immediately affect internal organs.

• If possible, do not use toners that require heating.
• Add acid to water.
• Do not contaminate sulfide or selenium toners with acids.

• Selenium toners give off large amounts of sulfur dioxide gas.
• Exposure to selenium salts to acid will result in toxic hydrogen selenide gas being produced.
• Sulfides release highly toxic hydrogen sulfide gas during toning or when treated with acid. For example, with two bath sulfide toners, make sure that you rinse the print well after bleaching in acid solution before dipping it in the sulfide developer.

• Avoid thiourea whenever possible because of its probable cancer status.
• Ensure good ventilation of the darkroom. At least, 10 air changes per hour.
• Wear gloves and goggles.
• If a splash occurs, flush affected areas (15-20 minutes for eyes) immediately with water using an eyewash or safety shower.
• Cover all solutions when not in use to prevent evaporation or release of toxic vapors and gases.

Disposal: -Save and send to EH&S for disposal.

Hardeners often contain formaldehyde (suspected human carcinogen) which is poisonous, very irritating to the eyes, throat and breathing passages. It can also cause dermatitis. Affected areas are anesthetized during prolonged exposures so the user may not smell or feel it and may not realize the duration of the exposure.

• Formaldehyde is a sensitizer, so the more one is exposed - the less a dose it takes to have effects. If you smell formaldehyde, you may be overexposed. Call EH&S at 2-3393 for monitoring.

• Ensure good ventilation of the darkroom. At least, 10 air changes per hour.
• Wear gloves and goggles.
• If a splash occurs, flush affected areas (15-20 minutes for eyes) immediately with water using an eyewash or safety shower.
• Cover all solutions when not in use to prevent evaporation or release of toxic vapors and gases.

-Un-used or concentrated solutions - send to EH&S for disposal.

The laboratory manager must approve of all alternative processes. No photochemicals should be used without a Material Safety Data Sheet (MSDS) being provided to the Lab Manager and read by the user. When purchasing the photochemicals, ask the supplier for the MSDS.

Color processing: In general, color processing uses more complex and hazardous chemical processes than black and white processing.

• Read the MSDS for each chemical before use.
• Wear gloves and goggles.
• Ensure good ventilation of the darkroom.
• Color processing requires more frequent air changes than black and white processing.
• Avoid color developers that contain para-phenylenediamine

• If a splash occurs, flush affected areas (15-20 minutes for eyes) immediately with water using an eyewash or safety shower.
• Cover all baths when not in use to prevent evaporation or release of toxic vapors and gases.

• Less Hazardous: denatured alcohol, acetone, isopropanol, mineral spirits; however fire hazard increases.

• More Hazardous: aromatic hydrocarbons, chlorinated hydrocarbons, cellosolves and cellosolve acetates.

McCann, Michael. (1994). Photographic Processing Hazards. Art Hazards News. Published by Safety in the Arts. New York, NY.