University of Victoria
Health and safety are vital issues, and no one in the University has a right to endanger either themselves or anyone else through uninformed or negligent use of implements, materials, or machinery. This manual has been compiled to provide basic information on safe practices and procedures in the Visual Arts. It is intended to protect you and those around you. Each student and staff member has received a copy. It is a basic requirement that you read and understand this manual before beginning to work in the Department of Visual Arts. Read it now. If you have any questions about the contents, please contact the Department's safety officer or the Department Chairman. Anyone who implements, materials, or machinery in a hazardous or potentially hazardous manner may be immediately barred from further access to the department and may be subject to additional disciplinary action.
Occupational Health and Safety Policy
It is the policy of the University to take all reasonable steps to:
Failure to observe the University's Occupational Health and Safety policies and procedures may result in disciplinary action.
Safety is the responsibility of everyone on campus. Specific responsibilities are as follows:
In order to take preventative measures it is important to note the following:
Inhalation: This is the major route of entry for airborne chemicals. The chemicals can have a direct effect on the nose, upper respiratory tract and the lungs or they can enter the blood stream and thus affect the blood, bone, heart, brain, liver, kidneys or bladder.
Ingestion: This is not normally a direct route of entry from exposure except by willful or accidental ingestion. Materials can also enter the stomach through indirect means. For example, the lung has a cleaning mechanism which pushes material out of the lung where it can be swallowed. This can result in an exposure to most of the internal organs or even in a local action on the stomach wall.
Skin Contact: Some materials are absorbed through the skin and therefore when they enter the bloodstream they can be transported throughout the body and accumulate in, or affect, the most sensitive areas of the body. Skin contact can also result in allergic reaction, the removal of the protective skin oil, or dermatitis. In some cases, the chemical contact may result in a cancerous lesion. Note: More detailed information on the hazards of chemicals found in art materials can be found in the Reading Room.
Arts and Reproduction
Many chemicals used in art can also affect the reproductive system. Some chemicals have specific effects on the male reproductive system, e.g., cadmium, manganese, and lead. Others have specific effects on the female reproductive system, e.g., toluene and xylene, which cause menstrual irregularities. All of these chemicals are common in art materials.
Pregnant and Breast-feeding Women: Chemicals and other factors which are thought to cross the placental barrier and possibly cause damage and birth defects, include lead, cadmium, mercury, copper, carbon monoxide, dyes, noise, vibration, and many organic solvents. The amount of material necessary to damage the fetus or embryo is much smaller than the amount which can injure the adult. The most sensitive time for chemical interference with normal development is from the 18th to the 60th day after conception. Other hazards include materials that can affect the respiratory and circulatory systems. Examples include solvents, dyes, metals, toxic dusts and gases, as well as strenuous activity and other stresses. Many chemicals, especially heavy metals and solvents, can be found in a woman's milk several hours after exposure and can affect the infant. AVOID USE OF SOLVENTS AND AEROSOLS.
Children: Children are more susceptible to the effects of hazardous chemicals than adults are and they should be closely supervised in the studio environment.
Smokers and Heavy Drinkers: These individuals are at a higher risk of damage to their lungs and liver respectively. Nicotine and/or alcohol mixed with toxic chemicals in art materials can cause synergistic and multiplicative reactions.
Individuals on Medications: Medications also create a greater risk. Consult your physician to ensure that any medication will not interact with substances in art materials to cause illness.
Note: Also within the high-risk group are the physically disabled, the elderly, and those with allergies or illnesses.
With the possible exception of lead, arsenic or chromate pigments, there is little danger of acute or immediate poisoning from accidental ingestion of paint. However, many of the pigments - especially lead, chromate and cadmium - can have serious long-term chronic effects from repeated exposures to small amounts. Some pigments can cause skin irritation and allergies. They include chrome yellow, zinc yellow, chromium oxide green and the cobalt pigments. The following list acts as a quick reference of common pigments and their hazards.
Common Pigments and their Hazards
Lead Pigments-Use with Caution: Chrome green Chrome yellow Flake White (white lead) Molybdenite (Moly) orange Naples yellow Possible Carcinogens-Use with caution: Cadmium orange Cadmium red Cadmium yellow (also other cadmium colors) Chrome yellow Diarylide (benzidine) yellow; Lithol red Phthalocyanine (phthalo) blue * Phthalocyanine (phthalo) green * Zinc yellow Pigments with Moderate Hazards: Burnt and raw umber Cobalt green Cobalt violet (cobalt phosphate) Cobalt yellow Manganese blue Manganese violet Toluidine (hansa) red Pigments with no Significant Hazard: Burnt and raw sienna English red Ivory black Mars black Mars yellow (and all other mars colors) Prussian blue Titanium white Ultramarine blue * paints contaminated with PCBs
Note: It is difficult to determine what pigments are in a tube of paint because product labels are often misleading. For example, a tube of Cadmium Red may in fact contain no cadmium. In other words, the traditional name, Cadmium Red, may or may not reflect the chemical content of the paint. Since it is impossible to research the health effects of the substance without knowing the exact identity of the pigments this information should be requested from the product manufacturers.
Cobalt dryers are slightly toxic by skin contact moderately toxic by inhalation, possibly causing allergies.
Solvents and paint thinners are moderately toxic by skin contact and inhalation and highly toxic by ingestion. This applies to odorless solvents as well. When using solvents and thinners have good general or local ventilation. The use of turpentine is not permitted in the studios. Lithotine, available from the supply store, is an acceptable substitute.
Lucite is a liquid plastic which is harmful by inhalation. Avoid prolonged exposure.
Acrylic paints usually contain stabilizers which release ammonia and a formaldehyde preservative. These can be inhaled by artists while they work or while paints are drying. Formaldehyde is a throat, eye, and respiratory system irritant which can cause dermatitis, allergies and asthma. It is also a suspected carcinogen. Risks can be minimized through dilution ventilation (such as a window exhaust fan) or simply by using a brand of acrylics which does not contain formaldehyde.
To ensure proper ventilation, toxic substances must be placed BETWEEN an individual and an exhaust fan. These are located in the painting, photography and printmaking studios. Where open windows (incoming air) and exhaust fans (outgoing air) coexist, the same positioning applies. In this case, however, the window must be kept behind the individual. This is to ensure that the toxic substance is drawn AWAY, and not PAST them.
Cut-off Saw ( Makita 2414) When using the cut-off saw, keep your hands away from the blade and wear eye-protection to guard against dust particles. Staple gun (Sencomatic, models PW and J ): When using the pneumatic staple gun always assume the tool contains staples; keep the tool pointed away from yourself and others. Disconnect staple gun from air supply before doing maintenance or clearing a jammed staple. The tools need special care and can break down quite easily.
Paint (Oil and Acrylic), canvas, wood, and solvents can be purchased at the supply store. Wood is stored in sculpture studio cage and may be picked up during store room hours. Students must have a receipt in order to get wood from the cage.
Stretcher building cannot interfere with sculpture classes; sculpture times will be posted. Gessoing is to be done in the painting studios only, not in the sculpture area.
Spray painting or aerosol spraying is to be done outdoors and not in the studios. A respirator and suitable clothing should be worn and drop sheets used.
Because oil paint and solvents do contain toxins it is important that they be kept away from the skin and therefore from entering the bloodstream. The best way to minimize risks is to reserve a set of clothing solely for studio use, or to wear coveralls or a smock over street clothes. Also less paint is inhaled if it does not dry and evaporate on clothing.
Food items (lunches) should not be stored in lockers that contain paints and/or solvents because of a high risk of contamination.
Store finished paintings in racks provided in order to keep work area clear. IT IS THE RESPONSIBILITY OF EACH STUDENT TO REMOVE OR DISPOSE OF ANY MATERIALS OR ASSIGNMENTS NO LONGER WANTED. FAILURE MAY RESULT IN THE DEPARTMENT DISPOSING OF UNWANTED MATERIAL AND THE COSTS BEING PASSED ON TO THE RESPONSIBLE PARTY. PERSONAL ITEMS LEFT IN THE DEPARTMENT BEYOND DEADLINE WILL BE DISCARDED.
The use of drawing fixatives are prohibited in the studios. Works must be sprayed outdoors. Fixative contains toluene and xylene, which are hazardous to health. Graphite, charcoal and chalk pastel can also be harmful if the dust is inhaled in excessive quantities. Take suitable precautions (i.e. wear a respirator) if doing a large scale work with powdered graphite.
Supplies Drawing materials and paper can be purchased from the supply store. Large drawing boards belonging to Visual Arts can only be used in the drawing studio.
Noise: Tools for both woodworking and metal working are often noisy, with noise levels ranging as high as 115 db. Wear proper ear protection, as continual exposure can cause permanent hearing loss. It is common sense to show consideration for others by avoiding extended use of a noisy tool in a crowded work space. Toxic Fumes: Many fumes from the metal being welded or the welding rods are highly toxic by inhalation. Welding of found metals can be hazardous if they give off toxic chemical fumes due to surface paint. Never work in confined spaces without ventilation. Safe Zone: A clear safe zone will be maintained around all power tools. Assignments and materials will be removed if they impede machine use. Dust: Wear goggles when using machines that create dust, such as the orbital sander. For the lathe which may produce wood chips, use face shield. Any process that can give off small metal filings such as drilling, buffing and grinding should be guartedd against with eye wear and/or face shield. For grinding rust off steel a respirator mask should be used.
Equipment and facilities are for the use of registered Visual Arts students and faculty only. They are not to be used for any unrelated outside projects, i.e. car repairs, etc. Facilities and tools are not to be moved or modified to suit individuals unless authorized by Chairman or the Senior Academic Assistant. Unsafe use, or misuse of equipment in the Department will result in the withdrawal of privileges. Students whose actions are considered detrimental to themselves or fellow students may be asked by any member of the Department to leave thu studio or stop using the equipment. Any equipment requiring repairs should be brought to the attention of the department.
Theory: The manner in which the torch is manipulated affects the gize and shape of the finished weld and is determined by the thickness of the metal to be welded, the joint edge preparation and fit up.
Practise: Factors to be Considered
In some cases where a wide weld bead is required,the torch may be moved from side to side, alternating with the rod, across the joint. The angle of the torch to the joint is determined by the thickness of metal on each side of the joint. In welding plates of equal thickness, the torch should be held at right angles to the joint. Where one side is heavier, the angle should be such as to bring both sides of the joint up to the melting temperature at the same time. The rod should always be held in line with the joint and protected from oxidation by the envelope of the flame. The size of the rod being used should be in proportion to the thickness of the metal being welded and the size of the tip in use. NEVER ADD ROD EXCEPT TO A MOLTEN PUDDLE WHEN FUSION-WELDING MILD STEEL.
For general shop use, the oxyacetylene proCess may be considered under four headings.
Uses: Welding of mild steel, copper, brass, etc. This is a method of joining metals in a molten state with or without adding filler rod. The metals form one solid piece upon cooling. The filler rod is generally of the same composition as the base metals.
Uses: Bronze-welding and brazing of various and dissimilar metals.e.g. Copper,brass,nickel,tool steels,malleable iron, etc. These are methods of joining metals without melting the base metal. The base metal is brought to a dull red heat only. With the base metal at the proper temperature and the aid of a suitable flux, metal from a filler rod (bronze, silver alloy, etc.) will form a strong molecular union with the base metal. The base metal has to be perfectly clean before the operation can be attempted.
Because of its intense heat and because it is so easy to control, the oxyacetylene flame has found wide use for such processes as flame-hardening, flame-softening, flame-descaling, heating, bending, straightening and forming of metals.
Cutting is accomplished by rapid oxidation or combustion of heated steel when a jet of pure oxygen from a cutting torch is directed against it. The steel is cut by first heating a small area to the kindling temperature with the preheating flames and then directing a jet of oxygen against the preheated area.
Adjusting pressure: the torch acetylene valve should be open whenever you are adjusting the delivery pressure to a torch. If it is not open, you cannot get a true working pressure reading on the regulator delivery pressure gauge. To increase pressure, turn the pressure-adjusting screw to the right (clockwise). To decrease the pressure, turn the pressure-adjusting screw to the left (counterclockwise). For the initial adjustment, before lighting the torch, follow these steps for both oxygen and acetylene adjustment.
Table 4: Pressure Chart Cutting Tip9 - Steel Thickness Oxygen Setting #3 TIP 1/4 - 3/4 STEEL 30-45 lbs. #5 - 1/2 - 40-45 Welding Tips - Steel Thickness #4 32 ga.- 1/32 in. STEEL #6 1/32 to 1/16 in. #15 1/16 to 3/16 in.
To Light Torch
To Close Down
When cutting, heat the metal until it glows red, starting at an edge. Cutting down from one point to another is always more efficient than cutting upwards. Avoid holding torch nozzle head to close to work as it causes a popping noise (backfire). To achieve a straight edge, clamp a guide piece of metal onto the work and rest the nozzle on it while slowly making the cut.
If the inner cone of flame has a tendency to curve, the tip should be cleaned. Be sure to keep tip clean at all times. Restrictions of the orifice will alter the flame and cause a lessening in the heat of the flame. Excess amounts of slag adhering to the outside of the tip are equally as detrimental to the efficient operation of the tip. Frequent cleaning of the tip is very important, particularly when working in confined areas. Proper care of all welding equipment is as necessary for good welding as proper welding techniques.
Theory: In Arc Welding, an electric arc struck between a hand-held electrode and the grounded work accomplishes the melting and fusion of the metal. There are basically two types of Arc Welding machines alternating current (AC) and direct current (DC). In AC machines the electrical power is supplied by wire to a transformer in the machine which converts it to useable current for the welder. DC machines have a generator coupled with the welder, run by a gas or electric motor, which produces electric power and supplies useable current directly to the welder. The Airco units supplied by C.A.D. will operate AC or DC and are portable.
The polarity switch changes the direction of current in the circuit. If the electrode is negative and the ground is positive, the current is said to be straight polarity. If the work is negative and the electrode is positive, the current has reversed polarity. The polarity and the amount of current are changed to meet specific requirements of different electrodes. The electrode holder, ground clamp, and cables' current is conducted from the welder to the work by two cables, one of which r uns to the electrode holder while the other goes to the ground clamp which is securely attached to the work. When the welder is on and the electrode in the holder comes in contact with the work, a circuit is completed (as seen by the arc) which allows the electrical current to flow.
Operation (Hobart T G - 201)
Note: Adjust controls with red dot only.
222 rods 3/32 dia. 35-200 (80 amps) 1/8 dia. R (125 amps) 5/32 dia. 135 -MAX (160 amps)
General Instructions: Maintain the correct arc length while running the bead (a bead is a continuous weld). If the arc is too short, your electrode will keep sticking, and you will not generate enough heat to melt the metal. If it is too long, the electrode metal will melt off in large globs, and you will get a splattered irregular bead with poor fusion between the metal. Make sure your current setting is correct. If it is too low, you will get "overlapping", where the metal melts off the electrode but does not fuse well with the base metal (the work). if it is too high, you may get "undercutting" due to poor penetration, where a groove is left next to the base metal along the bead's sides. This weakens the weld. Excessive current can also result in the electrode's melting too fast, and leaving a molten pool that is too large and irregular. The rate at which you move the electrode and the molten pool, or "crater", along the metal, building up the weld bead, is referred to as travel speed. If you go too slow, the metal piles up on top of the base metal and the penetration is poor. If you go too fast, the crater does not stay molten long enough and slag (impurities) are locked in the weld instead of floating to the surface where they can be chipped off. These two factors, speed and current, when correctly maintained will produce the proper crater, which is critical in achieving the correct penetration for a structurally sound weld. In general, penetration of the bead into the base metal should be from 1/3 to 1/2 the total thickness of the bead. If you find the crater getting too fluid, cool it by shifting the electrode (still maintaining the arc) to the side, or ahead of the crater.If you want to increase the width and volume of the bead you are running, you can weave the electrode along the bead line. Several patterns of weaving can be applied, a crescent, a figure eight, or a circular motion.
There are three primary variables in the M.I.G. welding process. They control the penetration, bead width, bead height, arc stability, deposition rate, and weld soundness. They are:
Other factors which affect the weld are called the secondary variables. These are:
NOTE: Increasing the wire feed speed increases the weld current. Decreasing the wire feed speed decreases the current. Maximum steel thickness to be welded is 3/16". Do not exceed since the machine is not designed for heavy metal. The contactors can be overloaded, and repairs are very costly. Before attempting to weld on a finished piece of work, it is recommended that practice welds be made on sample metal of the same material as that of the finished piece. The easiest welding for the beginner to experiment with in MIG welding is the flat position. The equipment is capable of flat, vertical and overhead positions.
Avoid dangerous Environments: Do not use power tools in damp or wet locations. Do not expose power tool in rain. Do not force tool: It will do the job better and safer at the job for which it was designed. Use right tool: Do not force small tool or attachment to do the job of a heavy-duty tool. Use safety glasses: Use safety glasses with most tools. A180 face mask or respirator if cutting operation is dusty. It is important for contact-leng wearerg to use safety glasses so that particles do not become trapped behind them and cause eye damage. Do not abuse cord: Never carry tool by cord or yank it to disconnect from receptacle. Keep cord from heat, oil, and sharp edges. Secure work: Use clamps or vise to hold work, especially on drill press. Disconnect tools: When not in use; before servicing; when changing blades, bits, cutters. Proper grounding: The tool should be grounded while in use to protect operator from electric shock. All plugs should have three prongs.
Keep hands away from the blade. Wear eye protection to guard against dust.
Cut-off wheel (Makita 2414)
When operating, make sure that the work is secured by the vise and that the vise has been tightened carefully. Loose material that can fly up is an obvious source of danger. To start the tool, simply pull the trigger. Release the trigger to stop, For continuous operation without having to keep your finger on the trigger pull the trigger and then push in the lock button with your thumb. To release the tool from lock position, depress the trigger again and push the lock button. Always wear eye goggles, gloves and ear protection. The cut-off wheel is designed to cut bar-stock and piping, not plate steel. Non-ferrous metals such as aluminum and brass can not be cut on this saw. Attempts to use the side of the wheel for grinding are prohibited as this results in disc fibers being cut and disc breakage. MATERIALS MUST BE: FIRMLY SECURE IN VICE.
All crosscutting is done by placing the material to be cut against the face boards, measuring the desired length on the lower scale or, grasping the trigger with one hand while holding the material against the backboards with the other hand and drawing the saw downward through the material. The spring return reel will assist in the return of the motor to the top of the frame.
Index the disk to the desired direction of ripping. Move the pan downward until the rip pointer points to the desired rip dimension. Use the pointer which corresponding to the rip direction being used. Tighten the lock lever, turn on the motor and depress the switch lock button. Feed the material into the saw from the proper direction, and turn off the motor when cut is finished. ALWAYS TURN MOTOR OFF WHEN INDEXING. Blade Cutting Depth
The blade cutting depth is adjustable to allow for partial through-cutting and to compensate for sharpened blades. To adjust the blade cutting depth, loosen hold down strap nut and knob, and raise or lower the saw to the desired depth of cut. The blade should not be allowed to cut into the filler board more than 1/8". Tighten the knob and strap nut securely before cutting.
Additional Operating Instructions:
Wear eye protection, Make sure the table is square with the [[dillc??]]. Change sand paper when worn. The orbital sander must be used from the right gide of the wheel to the center. Do not feed pieces from the left side as they will fly back at you causing potential harm. Large pieces of wood requiring sanding should be sanded with portable equipment. A face mask should be worn for all sanding.
The jointer is a power planing machine that smooths the surfaces of lumber, and form faces and edges that are straight and square. The jointer is a direct counterpart of the hand plane. It will plane surfaces, edges, bevels, chamfers, and tapers.
Safety rules for the Jointer
The planer (also called a surfacer) is a single purpose machine that planes stock to uniform thickness. It smooths the surfaces of lumber, and forms faces and edges that are straight and true.
Safety Rules for the Planer
Lathe (General 260)
The operating principle of the lathe is different than that of other power woodworking machines. In standard wood lathe operation the wood is mounted in the machine and rotated while the cutting edge is held stationary and controlled by the worker. It requires considerable skill to hold the cutting tool in the correct position and also control the feed and direction of the cut. The standard hand-turning wood lathe may have a variable speed motor or a belt drive that provides speeds rangging from about 600 to 3600 rpm. The size of the lathe is called the SWING and is determined by the largest diameter of work that can be turned or twice the distance from the bed to the center of the spindle. Several sizes of lathes are available; however, a 12" swing is the most commonly used. More complete specifications for the lathe would also include the length of the bed and the horsepower of the motor. Standard lathe beds are usually 36, 48 or 60" in length.
Safety Rules for the Lathe
Safety Rules For the Table
Cedar: Skin contact may cause skin allergies. Inhalation of sawdust may cause severe asthma, bronchitis, sneezing, nasal irritation, and conjunctivitis. Ingestion may cause gastrointestinal irritation.
Fir: Splinter wounds are hard to heal and may become infected.
Particle Board and Plywood: The glue in particle board and plywood contains formaldehyde which is hazardous by inhalation. Wear dust mask when ripping on the table saw and store these materials away from heat and moisture.
Materials such as paint stripper, shellac, varnish, stains, plastic wood, creosote, and enamel paints are all harmful by inhalation, ingestion and skin contact. Particular care should be taken not to use any of there substances in a crowded work space without adequate ventilation. Many paints and compounds (such as arsenic) are suspected carcinogens and can cause reproductive problems.
The most commonly used developer are hydro-quione, monomethyl para-aminophenol sulfate, and phenidone. Other common components of developing baths include an accelerator. often sodium carbonate or borax, sodium sulfite ag a preservative and potassium bromide as a restrainer or antifogging agent.
Developers are commonly available in powder form and must be dissolved to make the developing bath. They are skin and eye irritants, and some are strong sensitizers. Monomethyl paraaminophenol sulphate creates many skin problems and allergies to it are frequent. Hydro-quinone can cause depigmentation and eye injury after 5 or more years of continual exposure. Catechol and pyrogallol can be absorbed through the skin to cause severe poisoning. Phenidone is only slightly toxic by skin contact. Most developers are highly toxic by ingestion (some fatalities have occurred by accidentally drinking developer solution). Inhalation of powders is also hazardous.
Stop baths are usually weak solutions of acetic acid. Acetic acid is commonly available as pure glacial acetic acid or 28% acetic acid. Some stop baths contain potassium chrome alum as a hardener.
Fixing baths contain hypo or sodium thiosulfate as the fixing agent, acetic acid to neutralize developing action, and sodium sulfite as a preservative. Some fixing baths are hardened with alum (potassium aluminum sulfate) and boric acid (ag a buffer).
A common aftertreatment of negatives (and occasionally prints) is either intensification or reduction. [Intensification involves bleaching of the negative and subsequent redeveloping of the image. In this process, other heavy metals are usually added to the silver. Common intensifiers include mercuric chloride followed by ammonia or sodium sulfite, Monckhoven's intensifier consisting of a mercuric iodide/sodium sulfite, potassium bromide, and uranium nitrate. Reduction of negatives is usually done with Farmer's reducer, consisting of potassium ferrocyanide and hypo. Reduction can also be done with iodine/potassium cyanide, ammonium persulfate, and potassium permanganate/ sulfuric acid.
Toning a print usually involves replacement of silver by another metal, for example gold, selenium, uranium, platinum, or iron. In some cases the toning involves the replacement of silver metal by the brown silver sulfide, for example, in the various types of sulfide toners. A variety of other chemicals are also used in the toning solutions.
Many other chemicals are also used in black and white processing, including formaldehyde afi a prehardener, a variety of strong oxidizing agents as hypo eliminators (e.g. hydrogen peroxide and ammonia, potassium permanganate, bleaches and potassium persulfate), sodium sulfide to test for residual silver, silver nitrate to test for residual hypo, solvents such as methyl chloroform and freons for film and print cleaning, and concentrated acids to clean trays.
Concentrated sulfuric acid mixed with potassium permanganate or potassium dichromate produces highly corrosive permanganic and chromic acids. Hypochlorite bleaches can release highly toxic chlorine gas when acid is added or it is heated. Potassium persulfate and other strong oxidizing agents can be explosive when in contact with easily oxidizable materials such as many solvents and organic materials. Formaldehyde is a throat, eye and respiratory system irritant, which can also cause dermatitis and asthma. It is a suspected carcinogen.
Note: Most photographic chemicals, diluted in solutions normally used in processing, contain relatively low concentrations of toxic substances and therefore have low toxicity ratings for ingestion. Swallowing these solutions may produce mild transient gastro-intestinal symptoms. However, some toxicologists believe that major potential for hazards lies in continuous inhalation and skin absorption of these chemicals over long periods of time. Photographers expose themselves to vapors rising from large surfaces of trays, especially when darkroom temperatures exceed 21 C. and ventilation is poor. They expose the skin of their hands to all of these chemicals as they handle prints and move them through the various stages of processing. Low-level exposure to photographic chemicals is believed to have a cumulative effect on the various organs, such as the liver and kidneys, that must metabolize, store or excrete them, and on the central nervous system and respiratory tract. Such exposure has also led to the development of asthma and the worsening of other pre-existing lung conditions for some photographers, students and other persons living in close proximity to unventilated darkrooms.
Everyone who works with photographic chemicals should have a basic understanding of the nature of chemicals and their interaction with each other. Photographers should learn the art and the chemistry of photography at the same time.
Although the techniques of lithographic, intaglio, and relief printmaking vary considerably, they all involve inking the plates, setting up and operating the printing press, and cleaning up. The main hazards occur during the inking and cleaning steps. In handling prepared inks, there are no hazards due to inhalation of the pigment unless ink is allowed to dry on surfaces where it can eventually form a powder. The major hazards with inks are due to skin contact and accidental ingestion. This can be a problem particularly with hand-wiping techniques. Using bare hands increases the possibility of getting the ink in cuts and sores and of transferring ink from hands to mouth.
Many solvents are highly toxic by inhalation and moderately toxic by repeated skin contact, causing dermatitis. Do not wash your hands with solvents; appropriate gloves should be worn to avoid skin contact when cleaning up. Dispose of solvent-soaked rags in self-closing waste disposal cans that are emptied each day.
Fume hoods comprise the main ventilation system in the printmaking studio. Essentially a fume hood is an enclosure in which toxic, noxious, or otherwise harmful materials may be handled safely. The hood directs contaminants away from the work area by drawing out the contaminated air and expelling it. But in order to be effective, the fume hood must be used properly. Consult instructor.
Lithography can be done on either stone or metal plates. In both cases the purpose of the various chemicals used to prepare the plates or stone is to make the image areas ink receptive and to make the non-image areas water receptive and therefore ink repellent.
Before drawing on stone, the stone surface has to be ground smooth and the previous image erased. This is done with carborundum abrasives while the stone is wet and does not involve any hazards. Drawing materials for both stone and metal plates contain materials with high grease and fatty acid content. Hazards:
The basic steps in processing the image on stone consist of etching, dusting with rosin and talc, washing out the image with lithotine, rolling up with liquid asphaltum and then ink, and making corrections.
Most of the steps in processing zinc and aluminum plates are the same as for stone, except that metal plates often require a preliminary counteretch before drawing on the plate. Metal plate images also have to be fortified with plate bases, usually vinyl lacquer.
Photographic images can be transferred to metal plates that are coated with a light-sensitive emulsion. You can coat the metal plate yourself or use presensitized metal plates. For metal plates, diazo-sensitizing solutions, developers with highly toxic solvents, plate conditioners containing strong alkali, and other brand-name mixtures are used. Exposure of the coated plate is done with carbon arc, quartz mercury, or metal halide lamps. The Department has a metal halide lamp.
Intaglio printmaking processes include etching, engraving, drypoint, and collagraphs.
Due to the use of acids, fume hoods are necessary in the intaglio printmaking process. The following list outlines their proper utilization.
Fume Hood Utilization Guidelines
The main hazard of drypoint and engraving is the chance of cutting yourself through improper use of the tools. Hold the tools properly and always cut in a direction away from you with both hands behind the blade. Always keep the tools sharp.
Some of the ingredients which make up both hard ground and soft ground are flammable and can cause skin and eye irritation; avoid prolonged contact. Xylene is often used in making up hard ground, but as it is non essential to the mix and highly toxic, it should be deleted if you are making your own hard ground. Regular hard ground may be purchased in the store.
Alcohol: slightly toxic.
Rosin: slightly toxic by inhalation.
Asphaltum: toxic by skin contact, possibly causing skin cancer and skin irritation. Wash carefully after use.
Rosin can cause respiratory problems during this process because of the fine dust produced when it is shaken onto the plate. Wear respirator.
Zinc and copper plates are etched with nitric acid of varying strengths. Copper plates can also be etched with Dutch mordant or iron perchloride.
The most widely used photoresist contains the solvent ethylene glycol monomethyl ether acetate (methyl cellosolve acetate). The developer and dyes contain the solvent xylene (xylol). Exposure of plates is commonly done with ultraviolet sources such ag carbon arcs, mercury lamps, or metal halide lamps.
Wood and linocuts are made by gouging out areas of a smooth surface with cutting tools. Standard inks (both oil- and water-based) can be used to print the plates. Soft woods such as pine make ideal woodcut blocks. Battleship linoleum is available in the store. Heating the linoleum with the electric pad in the print shop makes cutting easier. Cleanup of the plates may be done in the sawdust box beside the sink. Woodcut tools can be either purchased at the store or signed out from the tool crib in sculpture.
Screen printing is essentially a stencil technique. Frames, cloth, squeegees and other supplies may be purchased at the Department supply store. Oil-based inks which are thinned by solvents are used in the print shop.
In screenprinting the main hazards lie in the large amounts of solvent used in the inks, bases, thinners, retarders, and general screen solvents. The inks may contain anywhere from 40% to 60% solvent; the bases around 80% solvent; and the thinners and retarders, 100% solvent. Basic good housekeeping methods as well as some personal protection are necessary when mixing the inks, printing and cleaning up. Through all these procedures, gloves or barrier creams should be used, since skin contact is considerable. Do not eat, drink, or smoke in the studio.
When mixing inks avoid leaving cans open or large amounts of ink on the palette for long periods of time. All through the mixing, printing and drying stages, solvent is constantly evaporating from the inks into the atmosphere at concentrations which are much higher than those found in intaglio or lithography. When the mixing is complete clean up the area entirely, i.e. don't leave unused ink or solvent-soaked rags lying around. The rags should be immediately placed in a safety disposal container. A slot hood or respirator should be used when dealing with toxic inks.
Paint thinner is moderately toxic by inhalation, and highly toxic by ingestion. It is also combustible. Paint thinner is most harmful during the printing and drying processes where it is used in large volumes. During printing, avoid letting the screen dry out to the point where an excessive amount of clean-up solvent will have to be used. If equipment is cleaned immediately after printing, less solvent is used. All clean-up should be done in screen-washing area. Solvents such as turpentine, benzine, naphtha, and kerosene are also used as modifiers. These solvents are classified as moderately toxic by inhalation and skin contact, and highly toxic by ingestion. Obey normal fire prevention rules. These include storing solvents in approved safety cans, using the red self-closing disposal cans and banning of smoking or open flames in the work area.
Lacquer thinner is a mixture of solvents which contains high amounts of toluene and other toxins. Skin contact and inhalation should be avoided. Ensure ventilation and wear gloves. Goggles are recommended to protect against splashes. Since it is highly flammable, contaminated rags and newspapers should be disposed of in red metal containers.
Printing is a highly hazardous process because of the toxicity of many solvents and the large volume of solvents used in the inks. Use a slot hood near the printing table. During printing, you are directly exposed to the vapors from the ink. When printing large editions, which takes some hours, this can involve considerable inhalation of solvent. The print is then hung up or placed in a rack for drying. For poster inks, this takes about 1.5-20 minutes as the solvent evaporates into the air. The drying of the prints creates similar hazards since large volumes of solvent can be evaporated into the air in a short period of time.
Shellac: Shellac may contain both ethyl alcohol and methyl alcohol. It can be thinned and removed with ethyl alcohol (denatured alcohol). Ethyl alcohol is only slightly toxic by skin contact or inhalation. Methyl alcohol is moderately toxic by ingestion.
Tusche: Tusche often contains small amounts of mineral spirits or turpentine; these solvents are - used to thin tusche, and kerosene is used to remove it from the screen. Mineral spirits, kerosene, and turpentine are moderately hazardous by inhalation and skin contact. Turpentine may also cause skin and respiratory allergies.
Precautions: Wear protective gloves and goggles when pouring, thinning, or washing out blockouts or resists. Do not use solvents to wash hands; use soap and water.
Film Stencils: Film stencils are adhered to the screen with adhering fluid for lacquer-type emulsion films and with a mixture of isopropyl/ alcohol and water for water-soluble emulsions. Water emulsion films are removed with water, and lacquer-type emulsions with film remover.
There are two types of photo stencil techniques in silkscreening: direct emulsions, in which the screen is coated with the emulsion, exposed, and then developed; and transfer film, in which the film is exposed and developed and then physically adhered to the screen. In both cases the emulsion can be presensitized or unsensitized. Unsensitized emulsions usually use ammonium dichromate for sensitization. Direct emulsions use water as developer, and indirect emulsions use hydrogen peroxide. Some emulsions may use silver nitrate ag sensistizer and caustic soda as developer. Exposure of the emulsions is done with an intense light source such as a No. 2 photoflood reflector bulb, sun lamp, and in some cases, carbon arc. The screens are reclaimed with bleach, hot water, and sometimes enzymes.
Timestamp: Monday, 24-Nov-2008 16:07:10 PST
Retrieved: Tuesday, 23-Oct-2018 06:55:24 GMT