Lithography, Intaglio and Relief Printing By Angela Babin, M.S., Michael McCann, Ph.D., C.I.H., and Devora Neumark Introduction This data sheet will introduce both hazards and safety precautions recommended for printmaking. There are many different printmaking processes, including lithography, relief printing, intaglio, and screenprinting. These specific methods, except screenprinting, will be addressed after a general introduction. Readers are encouraged to obtain CSA's other relevant publications such Water-based Inks: A Screenprinting Manual for Studio and Classroom, (Johnson, Stinett, 1990) and the "Silk Screen Printing" data sheet. Disposal of waste materials and solutions is discussed in Waste Management and Disposal for Artists and Schools, (Babin, McCann 1992) Inks Intaglio, lithography and relief inks consist of pigments suspended in either linseed oil or water as a vehicle. There can be additional hazardous binders or preservatives, etc. Hazards 1. Oil-based inks contain treated linseed oils. While linseed oil is not considered a hazard by skin contact or inhalation, ingestion of large amounts of some treated linseed oils might be hazardous due to presence of small amounts of toxic heavy metals. Oil vehicles are flammable when heated, and rags soaked in these may ignite by spontaneous combustion. Precautions 1. Know what materials are used. Obtain the material safety data sheets (MSDSs) on all products used. 2. Use the least toxic inks possible. 3. Children under the age of 12 should only use water-based inks containing non-toxic pigments, since oil-based inks require solvents for cleanup. 4. Do not use an open flame to heat linseed oil, linseed oil varnishes, or burnt plate oil. Take normal fire prevention measures (e.g. no smoking or open flames in work area). Place oil- soaked rags in self-closing disposal cans and remove from the studio each day. An alternative is to place the oil-soaked rags in a pail of water. Pigments Pigments are the colorants used in lithography, intaglio, and relief printing inks. There are two types of pigments: inorganic pigments, and organic pigments. Hazards 1. Pigment poisoning can occur if pigments are inhaled or ingested. For normal printing with prepared inks, the main hazard is accidental ingestion of pigments due to eating, drinking or smoking while working, or inadvertent hand to mouth contact. 2. The classic example of a toxic inorganic pigment in printmaking is lead chromate (chrome yellow). Lead pigments can cause anemia, gastrointestinal problems, peripheral nerve damage (and brain damage in children), kidney damage and reproductive system damage. Other inorganic pigments may be hazardous also, including pigments based on cobalt, cadmium, and manganese. (See CSA's data sheet Art Painting for more information) 3. Some of the inorganic pigments, in particular cadmium pigments, chrome yellow and zinc yellow (zinc chromate) may cause lung cancer if inhaled. In addition, lamp black and carbon black may contain impurities that can cause skin cancer. 4. Chromate pigments (chrome yellow and zinc yellow) may cause skin ulceration and allergic skin reactions. 5. The long-term hazards of the modern synthetic organic pigments have not been well studied. Precautions 1. Obtain MSDSs on all pigments. This is especially important because the name that appears on label of the color may or may not truly represent the pigments present. 2. Use the safest pigments possible. Avoid lead pigments. 3. Children under the age of 12 shouldn't use toxic pigments. 4. Avoid mixing dry pigments whenever possible. Never mix your own chrome yellow, zinc yellow, chrome green, molybdate orange or any other pigments which are known human carcinogens. If possible, do not mix highly toxic pigments such as lead white or cadmium colors. 5. If dry pigments are mixed, do it inside a glove box (a box with a glass or plexiglas top and holes in the sides for arms or inside a laboratory-type fume hood. Otherwise, wear a NIOSH-approved toxic dust respirator. Solvents In general, organic solvents are one of the most underrated hazards in art materials. Organic solvents are used in printmaking to dissolve and mix with oils, resins, varnishes, and inks; and to clean plates, rollers, tools, and even hands. Hazards 1. Repeated or prolonged skin contact with solvents can cause defatting of the skin and resultant dermatitis (rashes, drying and cracking of skin, itching, etc.). Many solvents, for example turpentine, methyl alcohol, toluene, and xylene, can also be harmful through skin absorption. 2. Inhalation of solvent vapors is the major way in which solvents are harmful. High concentrations of most solvents can cause narcosis (dizziness, nausea, fatigue, loss of coordination, coma, etc.). This can also increase the chances for mistakes and accidents. Research during the last 10 years has indicated that chronic occupational exposure to many solvents can cause permanent brain damage, with symptoms including loss of memory, behavioral changes, fatigue, spasticity, decreased intelligence, slower reflexes, poor hand-eye coordination, etc. Most of these studies are on mixed solvents so it is difficult to implicate particular solvents. There is at least one documented case of such brain damage affecting a silk screen artist. Solvents can also attack other organ systems besides the nervous system. In particular, turpentine can damage the kidneys, toluene and chlorinated hydrocarbons can affect the liver, and methylene chloride can affect the heart. 3. Many solvents are toxic if ingested. This is particularly a problem with young children swallowing solvents that have been placed in glasses or other food or drink containers, although this has also happened with adults. Swallowing 1/5 ounce of turpentine can be fatal to a 5-year old child. 4. Most solvents, except chlorinated hydrocarbons, are also either flammable or combustible. A solvent is flammable if its vapors can burn below 100þ F when a source of ignition is present; if the temperature has to be over 100þ F before it will burn, then the solvent is combustible. For example, ethyl alcohol and toluene are flammable, and kerosene and mineral spirits (Varsol or paint thinner) are combustible. Precautions 1. Obtain the MSDS on all solvent products used. Use the least toxic solvent possible. For example, replace the more toxic methyl alcohol (methyl hydrate) with denatured alcohol or isopropyl alcohol. 2. Do not use solvents with or around children under 12 years, or if you are pregnant or nursing. 3. Use dilution ventilation (e.g. window exhaust fan) for exhausting less than a cup of evaporated solvent per day. Or use local exhaust such as a laboratory hood or or slot hood. Adequate ventilation can also be provided if the work area is set up immediately in front (within 1-2 feet) of a window containing an exhaust fan at work level. 4. Keep minimum amounts of solvents on hand and purchase in smallest practical container size. Large amounts of solvents or solvent-containing materials should be stored in a flammable storage cabinet. 5. Never store solvents or solvent-containing materials in food or drink containers. Always label containers. 6. Do not allow smoking, open flames or other sources of ignition near solvents. 7. Have a class B fire extinguisher in the area. (If ordinary combustible materials are present, you may need a Class ABC fire extinguisher). 8. Wear gloves when handling solvents to avoid skin contact In particular do not use solvents to clean ink off hands. Baby oil is a good substitute. 9. If ventilation is not adequate, NIOSH-approved respirators with organic vapor cartridges can be worn. 10. Do not induce vomiting if petroleum distillates are swallowed. Give 1-2 glasses of water or milk and contact a regional Poison Control Center. Acids Acids are used in intaglio (acid etching) and in lithography. Strong acids commonly used include nitric acid, hydrochloric acid, and phosphoric acid, and less commonly carbolic acid (phenol), chromic acid, hydrofluoric and sulfuric acids. Hazards 1. Concentrated acids are corrosive to the skin, eyes, respiratory system and gastrointestinal system. Dilute acids can cause skin irritation on repeated or prolonged contact. 2. Chromic acid is a skin sensitizer, suspect carcinogen, and oxidizer. 3. Phenol is highly toxic by skin absorption and ingestion. It may cause severe kidney damage, central nervous system effects and even death if absorbed in large amounts. 4. Hydrofluoric acid is highly toxic and can cause severe, deep burns which require medical attention. There is no immediate pain warning from contact with hydrofluoric acid. 5. Concentrated nitric acid is a strong oxidizing agent and can react explosively with other concentrated acids, solvents, etc. Nitric acid gives off various nitrogen oxide gases, including nitrogen dioxide which is a strong lung irritant and can cause emphysema. Precautions 1. Know what is used. Obtain the MSDS for all acids. 2. Whenever possible avoid concentrated acids. 3. Children under the age of 12 should not be using or around acids. 4. Doing acid etching requires working in a enclosed hood, or in front of a slot exhaust hood or window exhaust fan at work level. 5. Store concentrated nitric and chromic acids away from organic materials. Concentrated nitric acid should always be stored separately even from other acids. 6. An important safety rule when diluting concentrated acids is to add the acid to the water, never the reverse. 7. Wear appropriate gloves, goggles and protective apron or lab coat when handling acids. 8. If adequate ventilation is not available, wear a NIOSH-approved respirator with acid gas cartridges. Do not use air-purifying respirators with nitric acid because the nitrogen dioxide cannot be detected by odor, and it is therefore not possible to detect odor breakthrough with charcoal cartridges. 9. An emergency shower and eyewash fountain that is not hand-held should be in studios where concentrated acids are mixed or used. Portable eyewash bottles are not recommended. If acid is spilled on your skin, wash with lots of water. In case of eye contact, rinse the eyes with water for at least 15-20 minutes and contact a physician. 10. Do not induce vomiting if concentrated acids are swallowed. Give 1-2 glasses of water or milk and contact a regional Poison Control Center. 11. Used acid solutions should be disposed of by neutralizing with sodium bicarbonate (baking soda) before being poured down sink with lots of water. Lithography Lithography uses either zinc and aluminum metal plates or stones for printing. It involves use of a variety of chemicals to make the image ink-receptive and non-image areas receptive to water and ink-repellent. Plate and Stone Preparation A variety of drawing materials with high wax and fatty acid content are used to make the image, including tusche and lithographic crayons. Airbrushing liquid drawing materials or using spray enamel or lacquer is also common. Other materials used in stone or plate processing include etch solution containing acids and gum arabic, counteretch solutions containing acids and sometimes dichromate salts, and fountain solutions containing dichromate salts. Phenol (carbolic acid) has been used for removing grease from stones, and a variety of solvents including lithotine, gasoline, kerosene, and mineral spirits, which are used for diluting drawing materials, washing out images and correction of images. Talc and rosin mixtures are also used. Metal plates are prepared with solvent-based vinyl lacquers. Hazards 1. Acids used include phosphoric, nitric, acetic, hydrochloric, hydrofluoric and tannic acids. The concentrated acids are corrosive and even dilute acid solutions can cause skin irritation from prolonged or repeated contact. Hydrofluoric acid and phenol are the most dangerous to use. 2. Lithotine, kerosene, and mineral spirits are skin and eye irritants and inhalation can cause intoxication and respiratory irritation. Gasoline is highly toxic because it usually contains other toxic additives including benzene (which can cause leukemia and aplastic anemia), lead additives, etc. 3. The solvents contained in vinyl lacquers can include highly toxic isophorone and cyclohexanone. Methyl ethyl ketone (MEK), which is moderately toxic, is often used as a thinner. 4. Dichromate salts may cause skin and nasal ulceration and allergic reactions, and are suspect cancer-causing agents. 5. Rosin dust may cause asthma and allergic dermatitis. There is the hazard of explosion from the buildup of rosin dust, in enclosed rosin boxes, around an ignition source. 6. Talcs may be contaminated with asbestos and silica. 7. Airbrushing drawing materials or using spray enamel paints is more hazardous than drawing with a brush because the inhalation hazard is higher. Precautions 1. Obtain the MSDS for all materials used. 2. See Acids and Solvents sections for the precautions with acids and solvents. 3. Use the least toxic solvents. Gasoline should never be used. Lithotine and mineral spirits are less toxic than the more irritating kerosene. 4. Use asbestos-free talcs such as baby powders. 5. Avoid dichromate-containing counteretches and fountain solutions if possible. 6. Do not use hydrofluoric acid if possible. 7. Air brushing or application of spray paints should only be done in a spray booth. 8. Local exhaust ventilation such as a slot hood, or window exhaust fan 1-2 feet away is needed for vinyl plate lacquers. 9. Dilution ventilation (e.g. window exhaust fan) can be used when working with small amounts of solvents. 10. An emergency shower and eyewash fountain should be installed where concentrated acids are mixed and used. 11. Appropriate gloves, goggles and a protective apron should be worn when mixing or using concentrated acids. 12. If adequate ventilation is not available for using solvents, a NIOSH-approved respirator with organic vapor cartridges is recommended. 13. Do not use phenol. Printing and Cleanup Many art lithographic inks contain treated linseed oil as a vehicle, and are thus not solvent-based. However, some lithographers use commercial lithographic inks which can contain some solvents, such as mineral spirits. For all types of lithographic inks, solvents are used to make image corrections on the press, to remove images, and to clean the press bed and rollers. Hazards 1. Some roller cleaners and glaze cleaners can contain chlorinated hydrocarbons such as perchloroethylene and methylene chloride. Most chlorinated solvents (except 1,1,1-trichloroethane) have been shown to cause liver cancer in animals and are therefore suspect human carcinogens. In addition perchloroethylene can cause liver damage, and methylene chloride heart attacks. Precautions 1. Know materials used. Obtain the MSDS for all solvents. See Solvents section for the precautions with solvents. 2. Choose products that do not contain chlorinated solvents whenever possible. 3. For small scale solvent use in correcting images or cleaning the press bed using lithotine or mineral spirits, dilution ventilation (e.g. window exhaust fan) is sufficient. 4. For roller and glaze cleaning, and larger scale solvent use, local exhaust ventilation such as a slot hood is recommended. Similarly, a window exhaust fan can be set up within 1-2 feet of the work station. 5. If local exhaust ventilation is not present, use NIOSH-approved respirators with organic vapor cartridges for larger scale solvent use or if using chlorinated solvents. Intaglio Intaglio is a printmaking process in which ink is pressed into depressed areas of the plate and then transferred to paper. These depressed areas can be produced by a variety of techniques, including acid etching, drypoint, engraving and mezzotint. Etching Etching involves use of dilute nitric acid, Dutch mordant (hydrochloric acid plus potassium chlorate) or ferric chloride to etch the zinc or copper (respectively) metal plate. Unetched parts the plate are protected with resists such as stopout varnishes containing ethyl alcohol, grounds containing asphaltum or gilsonite and mineral spirits, rubber cement, and rosin or spray paints for aquatinting. Sometimes, soft grounds contain more toxic solvents. Hazards 1. See Solvents section for the hazards of solvents. 1,1,1- trichloroethane found in some soft grounds is moderately toxic by inhalation under normal conditions but may cause fatalities at very high concentrations. 2. See Acids section for the hazards of acids. In particular nitric acid etching releases the respiratory irritant nitrogen dioxide which has poor odor warning properties. Large acute overexposures may cause pulmonary edema (chemical pneumonia), and chronic exposure may cause emphysema. During the etching process, flammable hydrogen gas is also produced. 3. Concentrated nitric acid is a strong oxidizing agent and can react with many other chemicals, especially solvents or other organic compounds, to cause a fire. 4. Mixing hydrochloric acid with potassium chlorate to make Dutch mordant produces highly toxic chlorine gas. Several years ago, five art students and teachers had chlorine poisoning in Canada from mixing Dutch mordant without proper ventilation. Potassium chlorate is a key ingredient in many pyrotechnics, and is a potent oxidizing agent. It can react explosively with organic compounds, sulfur compounds, sulfuric acid or even dirt or clothing. On heating it can violently decompose to oxygen and potassium chloride. Storage and use are very dangerous require special precautions especially when mixing. 5. Rosin dust (and asphaltum dust which is also sometimes used) is combustible. Sparks or static electricity have caused explosions in enclosed rosin and aquatint boxes. Rosin dust may also cause asthma and dermatitis in some individuals. 6. Inhalation of solvents and pigments can result from use of aerosol spray paints. Precautions 1. Obtain the MSDS for all materials used. 2. See Solvents and Acids sections for specific precautions. 3. Secondary schools should not use Dutch mordant. Artists, colleges and universities should use it with extreme caution. A safer substitute for etching copper plates is ferric chloride (iron perchloride). This forms acidic solutions so should be handled accordingly, but does not have the dangers of handling concentrated acids. Ferric chloride solution might cause minor skin irritation from prolonged contact. 4. Application of grounds or stopouts should be done with local exhaust ventilation, (e.g. slot or enclosed hood). Working immediately in front of a window containing an exhaust fan at work level will also provide adequate ventilation. 5. Application of spray paints should be done inside a spray booth that exhausts to the outside, or outdoors. 6. Acid etching should be done with local exhaust ventilation. See section on precautions for Acids for more information. Note that the acid gases will eventually corrode ordinary fans or galvanized ducts. 7. Rosin (or asphaltum) boxes should be explosion-proof. Use sparkproof metal cranks, explosion-proof motors, or compressed air. Don't use hair dryers to stir up rosin dust. Other Techniques Drypoint, mezzotint and engraving use sharp tools to incise lines in metal plates. Hazards 1. One major hazard associated with these types of processes involves accidents with sharp tools. 2. Long-term use of these tools can cause carpel tunnel syndrome, which can cause numbness and pain in the first three fingers. Severe cases can be incapacitating. Precautions 1. Keep tools sharp, store them safely and always cut away from yourself. 2. When possible, clamp down plates to avoid slippage. 3. Minimize the chance of carpel tunnel syndrome by choosing tools with wide handles, avoiding tight grips, and doing hand flexing exercises during regular rest periods. Set work table height so wrist flexing motions are minimal. Printing and Cleanup Intaglio inks contain pigments, treated linseed oil and modifiers. Printing involves placing the ink on the inking slab, inking the plate by hand, and then printing. Cleanup of inking slab, press bed, and cleaning the plate is done with a variety of solvents including mineral spirits, alcohol, lithotine, turpentine, etc. Hazards 1. Preparing your own inks from dry pigments can involve inhalation of toxic pigments. See Pigments section for the hazards of pigments. 2. See Solvents section for the hazards of solvents. Plate cleaning is more hazardous than cleaning inking slabs or press beds because larger amounts of solvents are used. 3. Lithotine, turpentine, or oil-soaked rags can be a spontaneous combustion hazard if improperly stored. Precautions 1. See Pigments and Solvents sections for the specific precautions for pigments and solvents. 2. Dilution ventilation (e.g. window exhaust fan) is sufficient for cleaning press beds and inking slabs if small amounts of solvents are used. 3. For cleaning resists off etching plates, use local exhaust ventilation, (e.g. slot or enclosed hood). Working immediately in front of a window containing an exhaust fan at work level will also suffice. 4. Oil-soaked rags should be stored in approved, oily waste cans that are emptied each day. An alternative is to store them in a pail of water and then allow them to dry out for reuse or dispose of the wet rags by placing in a plastic bag. 5. NIOSH-approved respirators with organic vapor cartridges can be used if ventilation is not adequate. Relief and Other Printing Processes Other printing processes include relief printing, collagraphs, monoprints, and plastic prints. Relief Printing Relief printing techniques include woodcuts, linoleum cuts and acrylic plates for plaster relief. These techniques involve the cutting away of plate areas that are not to be printed. Relief inks can be oil-based or water-based. Hazards 1. Some woods used for woodcuts can cause skin irritation and/or allergies. This is particularly true of tropical hardwoods. See CSA's data sheet on woodworking for more detailed information. 2. Accidents involving sharp tools can result in cuts. 3. Wood carving and cutting tools can cause carpel tunnel syndrome. This was discussed earlier in the section that included drypoint and mezzotint. 4. Caustic soda (sodium hydroxide) is sometimes used for etching linoleum. It can cause skin burns and severe eye damage if splashed in the eyes. 5. Eating, drinking or smoking while printing can result in accidental ingestion of pigments. 6. Hazardous solvents are used in stopouts and resists in linoleum etching, and for cleaning up after printing with oil-based inks. See Solvents section for more information on the hazards of solvents. Precautions 1. Obtain the MSDS for all materials used. 2. See Acids and Solvents sections for precautions with acids and solvents. 3. Children under the age of 12 should not be doing woodcuts because of the tool hazards. Linocuts using heat-softened linoleum and water-based inks can be used with older children. 4. Water-based inks are preferable to oil-based inks since solvents are not needed. 5. Use dilution ventilation (e.g. window exhaust fan) when applying resists for linoleum plates. 6. Wear appropriate gloves, goggles and protective apron when handling caustic soda. 7. An emergency shower and eyewash fountain should be available. If the chemical is spilled on your skin, wash with lots of water. In case of eye contact, rinse the eyes with water for at least l5-20 minutes and contact a physician. 8. Vacuum or mop up all wood dust so as to diminish inhalation of wood dust. 9. Always cut in a direction away from you, with your free hand on the side or behind the hand with the tool. 10. Carpel tunnel syndrome can be minimized or avoided by using tools with wide handles, avoiding tight grips, and rest periods with hand flexing exercises. Linoleum cutting is softer to work, and thus can reduce musculoskeletal injury. Collagraphs Collagraphs are prints produced by using a collage of different materials glued onto a rigid support. A wide variety of materials and adhesives can be used in making collagraphs. Hazards 1. Rubber cement, a common adhesive used with collagraphs, is extremely flammable and most rubber cements and their thinners contain the solvent n-hexane which can cause damage to the peripheral nervous system (hands, arms, legs, feet) from chronic inhalation. 2. Epoxy glues can cause skin and eye irritation and allergies. 3. See the Solvents section for solvent hazards found in adhesives. 4. Spraying fixatives on the back of collagraph plates to seal them can involve risk of inhalation of the solvent-containing spray mist. 5. Sanding collagraph plates which have been treated with acrylic modeling compounds or similar materials can involve inhalation of irritating dusts. 6. A wide variety of other materials with varying toxicities can be used in making collagraph plates. Precautions 1. Know the hazards of materials used. Obtain the MSDSs from the manufacturer. 2. Use the least toxic materials available. In particular use water-based glues and mediums (e.g. acrylic medium) whenever possible. Some rubber cements are made with the solvent heptane, which is less toxic than n-hexane, primarily because peripheral neuropathy is not associated with its use. 3. Use dilution ventilation (e.g. window exhaust fan) with small amounts of solvents and large amounts of acrylic medium (due to the presence of small amounts of ammonia). For highly toxic solvents or large amounts of solvents or other toxic chemicals, use local exhaust ventilation (e.g. slot hood, enclosed hood, etc.). A window exhaust fan can be used if set up only 1-2 feet away. 4. Use spray fixatives in a spray booth that exhausts to the outside, or outdoors. 5. Wear gloves when using epoxy glues. 6. Wear a NIOSH-approved toxic dust respirator when sanding collagraph plates. Plastic Prints Plastic prints can involve making prints from a wide variety of plastic materials and resins. Hazards 1. Plastic prints can involve hazards from inhalation of plastic resin vapors (e.g. epoxy resins) and also from inhalation of decomposition fumes from drilling, machining, sawing, etc. of finished plastics. Precautions 1. Obtain the MSDS for all materials used. 2. See Solvent section for the precautions with solvents. 3. Use the least toxic material available. 4. Use dilution ventilation (e.g. window exhaust fan) with small amounts of solvents and when fabricating finished plastics. For highly toxic solvents or plastics resins, or large amounts of solvents or other toxic chemicals, use local exhaust ventilation such as a slot or enclosed hood, or a window exhaust fan 1-2 feet away. 5. Wear a NIOSH-approved respirator with organic vapor cartridges when using plastics resins if local exhaust ventilation is not available. Monoprints Monoprints involve standard intaglio, lithographic and other printmaking techniques, but only one print is made. Monoprints have the same hazards involved in plate preparation and printing as the parent techniques. Photoprintmaking Photoprintmaking involves exposing a light-sensitive emulsion or film to ultraviolet light through a transparent support containing an opaque image to transfer the image to a plate. The transparency through which the photoemulsions are developed can include drawings on a transparent support such as Mylar or acetate, or photographic images processed on graphic arts film to yield a positive image. Several photoprintmaking methods will be discussed. Photolithography Photolithography involves transferring graphic images to stones or metal plates that are coated with a light-sensitive emulsion. One can coat the stone or metal plate, or use presensitized metal plates. Light-sensitive emulsions used on stone consist of a mixture of powdered albumin, ammonium dichromate, water, and ammonia; commercial emulsions are usually based on diazo compounds. Developing solutions for these mixtures often contain highly toxic solvents. Diazo-sensitizing solutions, developers with highly toxic solvents, plate conditioners containing strong alkali, and other brand name mixtures are used for metal plates. Hazards 1. Diazo photoemulsions are the least hazardous although they can cause eye irritation. 2. Ammonium dichromate used for stone is a probable human carcinogen, is moderately toxic by skin contact, and may cause allergies, irritation, and external ulcers; it is highly flammable and a strong oxidizer. 3. Ammonia is a skin irritant and highly toxic by inhalation. Ammonia is highly corrosive to the eyes. It has good odor-warning properties. 4. Light exposure sources include photoflood lamps, vacuum Poly- Lite units, and carbon arcs. Carbon arcs produce large amounts of ultraviolet radiation which can cause skin and eye damage and possible skin cancer. Carbon arcs also produce hazardous metal fumes, and ozone and nitrogen dioxide (which can cause emphysema), and toxic carbon monoxide. 5. Screen cleaning solutions include strong caustic solutions, enzyme detergents which can cause asthma, and chlorine bleach. These are skin and respiratory irritants. 6. Many solvents used in developing solutions are highly toxic both by inhalation and skin absorption. 7. Plate conditioners contain alkalis that are highly corrosive to skin and eyes. Precautions 1. Obtain a MSDS for all materials used. 2. See Solvents section for more precautions with solvents. 3. Avoid ammonium dichromate and use presensitized plates if possible. If you cannot substitute, wear gloves and goggles. Store it away from heat, solvents and other organic materials. 4. Use ammonia solutions or solvent-containing photolithographic solutions inside a laboratory hood, or in front of a slot exhaust hood. Wear gloves, goggles, and if ventilation is inadequate, a NIOSH-approved respirator with organic vapor cartridges for solvents, and an ammonia cartridge for ammonia. 5. A window exhaust fan provides the minimum ventilation needed for using bleach. 6. Do not use carbon arcs unless they are equipped with local exhaust ventilation exhausted to the outside. Quartz mercury or metal halide lamps are safer. 7. Paint walls in the darkroom with a zinc oxide paint which will absorb ultraviolet radiation. When using the carbon arc, wear welding goggles with as dark a shade number as enables you to see. 8. Wear gloves, goggles and plastic apron or laboratory coat when mixing hazardous chemicals. A glove box or wear a NIOSH-approved toxic dust respirator when mixing powders. 9. If you spray diazo photoemulsions without a local exhaust spray booth, wear goggles and a NIOSH approved toxic dusts and mists respirator. 10. An eyewash fountain should be available. In case of splashes in the eyes rinse with water for at least 15-20 minutes and contact a physician. Photoetching Photoetching is usually done using the KPR products. Photoresist dyes often contain a variety of highly toxic solvents, including ethylene glycol monomethyl ether acetate (2-ethoxyethyl acetate, cellosolve acetate), ethylene glycol monoethyl ether, and xylene, and benzaldehyde. The developers contain xylene and ethylene glycol monomethyl ether acetate (2-methoxyethyl acetate or methyl cellosolve acetate). Developers used for safer presensitized plates also also contain solvents. Exposure of the plate is done with ultraviolet sources such as carbon arcs, mercury lamps, or metal halide lamps. Hazards 1. See the Solvents section for the hazards of various solvents. In particular, methyl and ethyl ether acetates of ethylene glycol are highly toxic by skin absorption and inhalation and can cause anemia, kidney damage, testicular atrophy and sterility in men, and miscarriages and birth defects in pregnant women. 2. Xylene is moderately toxic by skin absorption, and highly toxic by inhalation and ingestion. It is a strong narcotic. 3. The Photolithography section discusses carbon arc hazards. Precautions 1. See Solvents section for precautions with solvents. 2. Pregnant or nursing women, children, and men trying to conceive should not work with these materials. 3. Use photofloods or other light sources instead of carbon arcs. Precautions with carbon arcs is discussed in the Photolithography section. 4. Use presensitized plates if possible. 5. Use photoresist solutions with local exhaust ventilation, or wear an organic vapor respirator. Wear butyl rubber gloves when handling KPR solutions. Other Photoprintmaking Techniques Rarer techniques include photogravure, using rosin and ammonium bichromate, and photoimage wood engraving. Hazards 1. Photogravure uses an aquatint technique involving rosin dust or asphaltum. See Etching under Intaglio for hazards of rosin dust. 2. Potassium dichromate is used as a developing agent in photogravure. Potassium dichromate may cause skin and nasal ulceration and allergic reactions, and is a suspect cancer-causing agent. 3. Photoimage wood engraving uses photoemulsions. Precautions 1. Use sunlight, photofloods or other light sources instead of carbon arcs. 2. Wear gloves, goggles and protective apron when handling potassium dichromate. 3. Wear a NIOSH-approved toxic dust respirator when mixing powders. 4. An eyewash fountain should be available. In case of splashes in the eyes rinse with water for at least 15-20 minutes and contact a physician. Film Developing High contrast graphic arts films such as Kodalith are used to produce photographic images for photoprintmaking. There are various hazards of darkroom chemistry. These, and recommended safety precautions, are discussed in other CSA publications on photographic processes. For Further Information Written and telephoned inquiries about hazards in the arts will be answered by the Art Hazards Information Center of the Center for Safety in the Arts. Send a stamped, self-addressed envelope for a list of our many publications. Permission to reprint this data sheet may be requested in writing from CSA. Write: Center for Safety in the Arts, 5 Beekman Street, Suite 820, New York, NY 10038. Telephone (212) 227-6220. CSA is partially supported with public funds from the National Endowment for the Arts, the New York State Council on the Arts, the New York City Department of Cultural Affairs, and the NYS Department of Labor Occupational Safety and Health Training and Education Program. (c) Copyright Center for Safety in the Arts 1992