University of Victoria

Department of Visual Arts Health and Safety Manual

Jan 1993

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

Policy Statement

It is the policy of the University to take all reasonable steps to:

  1. protect the safety of all faculty, staff, students and visitors against work accidents and occupational hazards;
  2. comply with all relevant statutes, regulations and standards of government agencies and other regulatory authorities representing Occupational Health and Safety;
  3. give priority to safe working conditions and job safety practices in the planning, budgeting, direction and implementation of University activities;
  4. formulate and carry out continuing effective safety programs appropriate to University operations; and

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:

Students shall

  1. comply with the University's Safety Policy and Procedures, and departmental regulations associated with all of their University- related activities;
  2. seek guidance from their instructors or supervisors concerning safety-related knowledge and skills required to ensure safe performance in their activities;
  3. attend safety training programs and meetings as instructed;
  4. immediately report to their instructor or supervisor any accident, near miss, hazardous practice or condition with respect to their activities; and
  5. comply with the Health and Safety policies and procedures of other institutions when they are engaged in activities in these other institutions.

Visitors shall

  1. comply with the University's Safety Policy and Procedures and all other pertinent departmental regulations.

Safety in the Arts

In order to take preventative measures it is important to note the following:

How Chemicals Enter the Body

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.

High Risk Groups

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.

Safety in the Arts: Basic Preventative Measures:

  1. DO NOT eat, drink, or smoke in the studios.
  2. SUBSTITUTE less hazardous materials or techniques when possible. There are many instances where highly toxic chemicals can be replaced by less toxic materials.
  3. KNOW the materials and their hazards. If labels do not adequate information regarding contents, hazards, and precautions, use resource books to research the product your health is worth the effort.
  4. STORE materials safely. Use clearly labeled unbreakable containers, and always cover them when not in use to deter their evaporation into the environment. Do not store materials in food containers to avoid accidental ingestion.
  5. ENSURE proper ventilation.
  6. WEAR appropriate personal protective equipment such respirators, face shields, ear muffs, proper footwear and gloves.
  7. ASK if you are unsure about the operation of any equipment. Misuse of tools leads to accidents. No equipment is to be altered or modified unless on manufacturers recommendation.

PAINTING

Hazards

Oil Paint

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.

Oil Paint Dryers

Cobalt dryers are slightly toxic by skin contact moderately toxic by inhalation, possibly causing allergies.

Solvents

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

Lucite is a liquid plastic which is harmful by inhalation. Avoid prolonged exposure.

Acrylic Paint

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.

Ventilation

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.

Tools

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.

Miscellaneous Supplies

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

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

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.

Studio Clothing

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.

Storage of Materials

Food items (lunches) should not be stored in lockers that contain paints and/or solvents because of a high risk of contamination.

Storage of Paintings

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.

Drawing

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.

SCULPTURE

Hazards

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

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.

Hazards of the Metalworking Process

Precautions for Handling Oxygen and Acetylene

  1. Never use oxygen near flammable materials as it supports combustion.
  2. Open the oxygen cylinder valve slowly.
  3. Never tamper with or attempt to repair oxygen or acetylene cylinder valves.
  4. When opening an acetylene cylinder, never turn the key more than one and a half turns.
  5. Never use acetylene at more than 5 to 7 psi.

Welding and Cuffing Precautions

  1. Wear protective leather gloves,long-sleeved shirts and pants. This is to avoid both ultra-violet and material burns.
  2. Always use welding goggles or shield to prevent welder's flash. This condition affects the eyes and may require attention by Health Services or your physician.
  3. Place grey shields around- arc welding units to protect people working in the same area.
  4. Turn on fan located at south corner by exit of Room 106.
  5. Be aware that steel objects retain heat for a period of time after welding and cutting. Use caution when handling, and cool in sink.
  6. Do not move individual cylinders unless the valve protection cap, where provided, is in place, hand tight.
  7. Do not drop or abuse cylinders in any way. Make certain that cylinders are well fastened in their stations so that they will not fall.
  8. Do not use a hammer or wrench to open cylinder values.
  9. Always protect the hose or cable from being stepped on or run over. Avoid tangles and kinks. Do not leave the hose or cable so that it can be tripped over.
  10. Protect the hose and cylinders from flying sparks, hot slag, hot objects and open flame.
  11. Be sure that the connections between the regulators, adaptors, and cylinder valves are gas tight. Escaping acetylene can generally be detected by the odor.
  12. Do not use matches for lighting torches; hand burns may result. Use friction lighters. Do not attempt to relight a torch that has "blown out" without first closing both torch valves and relighting in the proper manner.
  13. Do not cut material in such a position as will permit sparks, hot metal, or the severed section to fall on the cylinder, hose, legs, or feet.
  14. When welding or cutting is to be stopped temporarily, release the pressure-adjusting screws of the regulators by turning them to the left.
  15. When the welding or cutting is to be stopped for a long time (lunch hour or overnight) or taken down, close the cylinder valves and then release all gas pressures from the regulators and hose by opening the torch valves momentarily. Close the torch valves and release the pressure-adjusting screws. If the equipment is to be taken down, make certain that all gas pressures are released from the regulators and hose and that the pressure-adjusting screws are turned to the left until free.

Oxyacetylene Welding

Components

  1. Oxygen tank, regulator (gauges) and hose.
  2. Acetylene tank, regulator, and hose. Oxygen and acetylene regulators have tank pressure and delivery pressure gauges.
  3. Welding torch and tips.

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

Torch movement

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.

General Techniques

For general shop use, the oxyacetylene proCess may be considered under four headings.

  1. Fusion-welding
  2. Bronze welding and brazing
  3. Heating, bending and flame-treating
  4. Cutting

Fusion-Welding

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.

Bronze Welding and Brazing

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.

Heating, Bending and Flame treating

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.

Cuffing

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.

Torch Operation (Cutting and Welding Tips)

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.

Oxygen Adjustment for Purox Valves and Handles

  1. Open oxygen valve on torch handle.
  2. Turn pressure-adjusting screw to desired pressure (as per charts);
    
                             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.
    
    
  3. Immediately close oxygen valve on torch handle (green colour hose). Do this after adjustments are made to determine gauge pressure.

Acetylene Adjustment

  1. Open acetylene valve on torch handle (red colour hose).
  2. Turn pressure-adjusting screw to 5 psi (this does not vary, regardless of problems).
  3. Immediately close torch acetylene valve (red colour hose).

To Light Torch

  1. Open acetylene valve and use striker to light torch immediately. Delay in lighting may result in a bigger pop due to gas buildup around the tip.
  2. Open pre-heat oxygen valve slowly until neutral flame is obtained (blue cone is brought down into nozzle).
  3. Press oxygen cutting lever and pre-heat valve to obtain neutral flame.

To Close Down

  1. Close torch acetylene valve first, then shut down preheat oxygen valve and torch oxygen valve.
  2. Back out pressure-adjusting screws on both acetylene and oxygen regulators (DO NOT SCREW VALVE IN TOWARDS REGULATORS).
  3. Check torch handles to make sure they are closed down.

Cutting

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.

Care of the Tip

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.

Arc Welding

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

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.

  1. Clamp grounding cable to work
  2. Turn power switch "A" to ON position
  3. Set AMP wheel to required setting
    
               222 rods  3/32 dia.   35-200     (80 amps)
    
                                1/8 dia.           R        (125 amps)
    
                              5/32 dia.    135 -MAX (160 amps)
    
    
  4. Set polarity wheel at either DC straight or AC, if you are using Artec 222 rod.
  5. Set the fine current control at 6 and adjust from that point: DOWN - if rod craters metal material UP - if stinger sticks to the material (Caution; break rod from work should this happen, as the rod will heat up.)
  6. Place electrode in the holder.
  7. Strike the arc; this removes flux from the rod and exposes the metal rod.
  8. When you have used up an electrode, simply release it from the holder, and put in a new one. You will have left an unfilled crater at the end of your bead. To fill this properly, strike the new arc about a 1/2" back in the bead you have already put down, and weld back over the crater, filling it as you go on with the bead.
  9. Clean your welds. As mentioned earlier, slag forms over the surface of the deposited bead. Chip this off with a slag hammer. Remember to use face shield and gloves as the flux can fly in all directions.
  10. When you have finished welding, turn off the machine and remove the electrode from the holder; wind up cable and hang on machine.

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.

M.I.G. Welding Operation(Metal Inert Gas):

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:

  1. Arc voltage
  2. Welding current (wire feed speed).
  3. Travel speed,

Other factors which affect the weld are called the secondary variables. These are:

  1. Stickout (distance between the end of the contact tube [tip] and the end of the electrode wire). The general rule is to maintain a 3/8" (9.5 mm.) stickout.
  2. Nozzle Angle - This refers to the position of the welding gun in relation to the joint. The transverse angle is usually 1/2 the included angle between the plates forming the joint. The longitudinal angle is the angle between the centerline of the welding gun and a line perpendicular to the axis of the weld. The longitudinal angle is generally called the nozzle angle, and either trails (pulls) or leads (pushes).

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.

Operation (M.I.G. Welder, Hobart Beta MIG 200)

  1. Turn on power.
  2. Adjust the Voltage Control to proper setting. Scale ranges from 1 to 9. The thinner the work the lower the voltage setting. Never change the voltage setting while welding.
  3. Adjust the wire feed speed. Scale is from O to 10. If speed is incorrect and an excess of wire issues from the tip, simply clip with wire cutters and adjust the feed speed to a lower setting.

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.

Cut-off saw (Makita LSI400

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.

Cross-Cutting

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:

  1. Keep hands away from the path of the blade.
  2. Be sure all clamp handles are tight before starting any operation.
  3. Turn off power when making adjustments.
  4. Return motor to top gently after each cross cut.
  5. Lock switch on ONLY when ripping.
  6. Don't rip from wrong direction; observe caution tag on unit.
  7. Don't slam motor against bottom or top of guide bars.
  8. Don't operate if spring return is broken.
  9. Don't force cutting action. Stalling or partial stalling of motor can cause major damage to motor winding.
  10. Don't index into ripping except at top of stroke.
  11. Don't remove small scraps from under motor

Bandsaw (Rockwell Delta Model 28- 200)

  1. First adjust upper guide assembly so it is 1/4" above the work.
  2. Allow the saw to reach full speed before starting to feed the work.
  3. Keep hands at least 2" away from blade when the saw is running.
  4. Make turns carefully and do not cut radii so small that the blade is twisted.
  5. Stop the machine before backing out of a long curved cut.
  6. If you hear a clicking noise, turn off the machine at once. This indicates a crack in the blade. WEAR FACE SHIELD AND GLOVES.

Orbital Sander(Rockwell Delta 82-710)

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.

Jointer (General Model 180)

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

  1. Before turning on the machine, make adjustments for depth of cut and position of fence.
  2. Do not adjust outfeed table or remove the guard.
  3. The maximum cut for jointing an edge is 1/8" and for a flat surface 1/16".
  4. Stock must be at least 12" long. Stock to be surfaced mu6t be at least 3/8" thick unless a special feather board is used.
  5. Feed the work so the knives will cut with the grain.
  6. Keep your hands away from the cutterhead even though the guard is in position. MAINTAIN AT LEAST 4" MARGIN OF SAFETY.
  7. Use a push block when planing a flat surface.
  8. Do not apply pressure directly over the knives with your hand.
  9. Do not plane end grain unless the board is at least 12" wide.
  10. The jointer knives must be sharp. Dull knives will vibrate the stock and may cause a kickback.

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

  1. Adjust the machine to the correct thickness of cut before turning on the power.
  2. Stock should be at least 12" long or several inches longer than the distance between the centers of the feed rolls.
  3. Surface only new lumber that is free of loose knots, and serious defects.
  4. Plane with the grain or at a slight angle. Never attempt to plane cross grain.
  5. Stand to one side of the work being fed through the machine.
  6. Do not look into the throat of the planer while it is running.
  7. Do not attempt to feed stock of different thicknesses, side by side through the machine.
  8. Handle and hold the stock only in an area beyond the ends of the table.
  9. Maintain the proper relationships of infeed and outfeed table surfaces and cutter head knife path.
  10. Do not back the work toward the infeed table.

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

  1. Before starting the machine, be sure that spindle work has the cup center properly imbedded, tailstock and tool rest are securely clamped, and there is proper clearance for the rotating stock.
  2. Before starting the machine for faceplate work, check to see that the faceplate is tight against the spindle shoulder and the tool support has proper clearance.
  3. Wear goggles or a face shield to protect your eyes, especially when roughing out your work.

Table Saw (General 360)

  1. Raise the blade until it projects above the table a distance equal to the thickness of the stock plus 1/4".
  2. Unlock the fence and move it along the guide bar to the required width. For an accurate setting check the measurement between the fence and the point of a tooth of the blade that is set toward the fence. Lock the fence in position, start the machine.
  3. Place stock flat on table with straight edge against fence and move stock into the blade. Continue steady feed through the entire cut. Stand to one side of the cutting when saw is in operation.

Safety Rules For the Table

  1. Be certain the blade is sharp and the right one for your work.
  2. Stand to one side of the operating blade and do not reach across it.
  3. Maintain a 4" margin of safety. (Do not let your hands come closer than 4" to the operating blade even though the guard is in position).
  4. The position of the stock must be controlled either by the fence or the miter gauge. Never cut stock free hand.
  5. Stop the saw before making adjustments to the fence or blade.
  6. Operators must control the feed and direction of the Cut. Students assisting should not push or pull on the stock, but only support it.
  7. BLADE COVER (GUARD) IS TO BE USED AT ALL TIMES.

Wood Types

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

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.

PHOTOGRAPHY

Developing Baths

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.

Health

General

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.

Specific

  1. 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.
  2. Sodium hydroxide, sodium carbonate, and other alkalis used as accelerators are moderately to highly corrosive by skin contact or ingestion. This i6 a particular problem with the pure alkali or with concentrated stock solutions.
  3. Potassium bromide is moderately toxic by inhalation or ingestion and slightly toxic by skin contact. Symptoms of systemic poisoning include somnolence, depression. Lack of coordination, mental confusion, hallucinations and skin rashes.
  4. Sodium sulfite is moderately toxic by ingestion or inhalation causing gastric upset, colic, diarrhea, circulatory problems, and central nervous system depression. It is not appreciably toxic by skin contact. If heated or allowed to stand for a long period in water or acid, it decomposes to produce sulfur dioxide which is highly irritating by inhalation.

Precautions

  1. Wear rubber gloves and goggles when handling developers in powder form or liquid solution. Wash gloves off before using again. Wear an approved dust respirator when pouring developer dusts.
  2. Do not put your bare hands in developer baths. Use tongs instead. If developer solution splashes on your skin or eyes, immediately flush with water.
  3. Label all solutions carefully to avoid accidental ingestion.
  4. Do not use para-phenylene diamine or its derivatives if at all possible.

Stop Baths

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.

Health Hazards

  1. Acetic acid, in concentrated solutions, is highly toxic by inhalation, skin contact and ingestion. It can cause dermatitis and ulcers, and can strongly irritate the mucous membranes. The final stop bath is only slightly hazardous by skin contact. Continual inhalation may cause chronic bronchitis. However contamination of the stop bath by developer components can increase the hazard.
  2. Potassium chrome alum or chrome alum (potassium chromium sulfate) is moderately toxic by skin contact causing dermatitis, allergies, and skin ulcers which might take a longtime to heal. It is highly toxic by inhalation.

Precautions:

  1. Wear gloves and goggles when handling concentrated solutions of acetic acid or when handling chrome alum. Always add acids to water, never the reverse.
  2. All darkrooms require good ventilation to control the level of acetic acid vapors and other vapors and gases produced in photography. Kodak recommends at least 10 air changes per hour for work rooms and local exhaust ventilation for processing and mixing tanks which produce toxic vapors or gases.
  3. Cover the acid bath (and other baths) when not in use to prevent evaporation or release of toxic vapors and gases.
  4. Store concentrated acids and other corrosive chemicals on low shelves so as to reduce the chance of eye or face injury in case of breakage.

Fixing Baths

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).

Health Hazards:

  1. In powder form sodium thiosulfate is not significantly toxic by skin contact. By ingestion it has a purging effect on the bowel8 Upon heating or long standing in solution, it can decompose to form highly toxic sulfur dioxite, which can cause chronic lung problems.
  2. Alum (potassium aluminum sulfate) is only lightly toxic. It may cause skin allergies or irritation in a few people.
  3. Boric acid is moderately toxic by ingestion or inhalation and slightly toxic by skin contact (unless the skin is abraded or burned, in which case it can be highly toxic).
  4. See previous sections for hazards of sodium sulfite and acetiC acid.

Precautions

  1. Ventilate the fixing bath as described in the previous section.
  2. Follow the named precautions for mixing, handling, and using chemicals as described in previous section.

Intensifiers and Reducers

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.

Health Hazards

  1. Potassium or sodium cyanide are highly toxic by inhalation and ingestion. Stomach acids can convert salt into the highly poisonous gas hydrogen cyanide. This can also happen if cyanide salts are treated with acid.
  2. Potassium ferrocyanide, although only slightly toxic by itself, will release hydrogen cyanide gas if heated, if hot acid is added, or if exposed to strong ultra-violet light (e.g. carbonarcs).
  3. Potassium chlorochromate can release highly toxic chlorine gas if heated or if acid is added.

Precautions:

  1. Dichromate intensifiers are probably the least toxic you can use. However, gloves and goggles should still be worn when preparing and using them.
  2. Do not exposed potassium chlorochromate to acid or heat.
  3. If possible do not use cyanides. If it is necessary to use them, do so only in a fume hood or other local exhaust hood. Take very careful precautions to ensure that cyanide solutions do not become contaminated with acids. Have an antidote kit available.
  4. The safest reducer to use is farmer's reducer. Do not expose farmer's reducer to hot acid, ultraviolet light, or heat.

Toner

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.

Health Hazards

  1. Many of the metals used in toning are highly toxic, particularly by ingestion.
  2. Sodium and potassium sulfide release the highly toxic gas hydrogen sulfide when treated with acid. Similarly, treatment of selenium salts with acid may release highly toxic hydrogen selenide gas.
  3. Thiourea is a suspected carcinogen since since it causes cancer in animals.

Precautions:

  1. Carry out normal precautions for handling toxic chemicals as described in previous sections. In particular wear gloves, goggles, and dust respirator when mixing and handling acids and alkalis.
  2. Take precautions to make sure that sulfide or selenium toners are not contaminated with acids. For example, with two bath sulfide toners, make sure you rinse the print well after bleaching in acid solution before dipping it in the sulfide developer.

Other Photographic Chemicals

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.

Health Hazards

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.

Precautions

  1. Cleaning acids should be handled with great care. Wear gloves and goggles and make sure the acid is always added to the water when diluting. An acid-proof apron should be worn to protect your body against splashes. The acid should be disposed of by pouring down the sink very slowly and flushing with water continually for at least 15 min. afterward.
  2. Do not add acid to hypochlorite bleaches and do not heat.
  3. Keep potassium persulfate and other strong oxidizing agents separate from flammable and easily oxidizable substances.
  4. The hazards of formaldehyde can be minimized through dilution ventilation, such as an exhaust fan.

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.

What to do

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.

  1. Always provide exhaust ventilation and a fresh source for the darkroom.
  2. Use good housekeeping practises. Wipe up all spills and splashes promptly; dispose of rags and papers contaminated with chemicals.
  3. Use aerosol spray products only in a spray booth or with efficient exhaust ventilation.
  4. Avoid skin contact with chemicals by using protective gloves or tongs.
  5. Change work clothes and launder them frequently. Wash hands well before eating, smoking, or using the toilet.
  6. Do not smoke, eat, or drink in the darkroom.

PRINTMAKING

General Hazards

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.

Clean-up

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.

Ventilation

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

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.

Drawing Materials

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:

  1. Solvents used in tusches are rated moderately toxic by inhalation. With the amounts of solvents used in drawing materials, normal ventilation is sufficient protection.
  2. Stone etches consist of solutions of gum arabic, nitric acid and tannic acid. Preparation of gum etches from concentrated acids Can cause severe burns and eye damage from splashes. The final gum etching only weakly acidic and is not significantly hazardous. Wear gloves when handling all concentrated acids to avoid skin contact. When diluting acid, always add acid slowly to the water and never the reverse.
  3. Lithotine, which is used to wash out the image, is a moderately toxic solvent.
  4. Liquid asphaltum used in roll-up and as a blockout contains pitch in an oil turpentine base and may cause skin irritation.

Stone Processing

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.

Hazards:

  1. Stone etches consist of solutions of gum arabic and nitric acid, phosphoric acid, or tannic acid. Preparation of gum etches from concentrated acids can cause severe skin burns and eye damage from splashes. The final gum etch is only weakly acidic and is not significantly hazardous.
  2. Rosin dust may cause respiratory allergies including asthma. Talc or French chalk often contains large amounts of asbestos. which may cause lung cancer and other forms of cancer. Talc provided by the Department is asbestos-free.
  3. Washout of the image is done with lithotine, a moderately toxic solvent.
  4. Liquid asphaltum used in roll-up and as a blockout contains pitch in an oil or turpentine base. It may cause skin irritation and possibly skin cancer.
  5. Counteretches used for correcting the image consist of either diluted acetic acid or saturated alum solution. Concentrated acetic acid is a highly toxic skin, eye, and respiratory irritant. Alum may cause skin allergies in some individuals.

Precautions:

  1. Wear gloves and goggles when handling all concentrated acids, to avoid skin and eye contact. When diluting acid, always add the acid slowly to the water, never the reverse.
  2. Replace talc or French chalks of unknown asbestos content with an asbestos-free talc, such as baby powder. Talc provided by the Department is asbestos-free.
  3. Use normal precautions when handling solvents to avoid skin contact and inhalation.
  4. Wash hands carefully to remove ink and asphaltum.

Metal Plate Processing:

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.

Hazards:

  1. Many acids are used in counteretches and etchess for metal plates, including acetic acid, nitric acid, hydrochloric acid, phosphoric acid, and tannic acid. Except for tannic acid, these acids are strong skin and eye irritants when concentrated. The final etches and counteretches are also acidic enough to cause mild skin and eye irritation.
  2. Many etches and fountain solutions contain ammonium or potassium dichromates or potassium chrome alum. These are moderately toxic by skin contact, causing severe rashes, irritation and surface ulcers. They are highly toxic by inhalation, possibly causing irritation, allergies and perforation of the nasal septum. They are suspected carcinogens.
  3. Lacquer thinner is used to prepare the plate for vinyl lacquers, the plate base. Since it contains high amounts of toluene and other toxins, skin contact and inhalation should be avoided.
  4. Vinyl lacquers used as plate bases contain highly toxic aromatic hydrocarbons and ketones. The major hazard is by inhalation, although these solvents also cause dermatitis.
  5. Corrections of the image are commonly done with moderately toxic solvents such as benzine, petroleum naphtha (lactol spirits), gasoline and kerosene. Brand-name mixtures, which often contain more toxic solvents, are also used.

Precautions:

  1. Wear gloves when handling or mixing solutions of concentrated acids.
  2. Use normal general ventilation when using moderately toxic solvents such as lithotine.
  3. When using lacquer thinner ensure adequate ventilation and wear gloves. Goggles are recommended to protect against splashes.
  4. Take normal precautions against fire and evaporation of solvents from solvent-soaked rags.
  5. Use solvents such as benzine or mineral spirits instead of the more hazardous gasoline or brand-name products of unknown toxicity.

Photolithography

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.

Hazards:

  1. Diazo photosensitive emulsions are eye irritants. Sensitizers containing sodium dichromate are skin and respiratory irritants and can cause corneal burns.
  2. Many of the solvents used in photolithographic developing solutions are highly toxic, both by inhalation and skin absorption.
  3. Plate conditioners contain alkalis that are highly corrosive to the skin and eyes.
  4. Carbon arc fumes are highly toxic. Hazardous amounts of these fumes can be inhaled without noticeable discomfort. Chronic effects include emphysema and severe pulmonary fibrosis or scarring. In addition, they emit large amounts of ultraviolet radiation, which is damaging to the eyes.

Precautions:

  1. When using a senzitizer always wear respirator, gloves, and goggles.
  2. When developing plates with mixtures containing highly toxic solvents use a fume hood or wear a respirator with a window exhaust fan to exhaust the vapors. Wear protective gloves and goggles.
  3. Wear goggles and gloves when handling strongly alkaline solutions.
  4. Do not use carbon arcs without proper ventilation. Quartz mercury or metal halide lamps are safer.

Intaglio

Intaglio printmaking processes include etching, engraving, drypoint, and collagraphs.

Ventilation

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

  1. Safety goggles or glasses should be worn when using a fume hood.
  2. Operations that may generate air-born contamininants must be carried out in a fume hood that is minimally certified for that purpose. (Fume hoods must be specifically certified for the use of CARCINOGENS, and PERCHLORIC ACID.)
  3. Keep your head outside the face (front vertical plane) of the fume hood.
  4. Prevent disruption of fume hood air flow patterns. To achieve this:
  5. DO NOT RAISE THE SASH HIGHER THAN THE LABELLED HEIGHT. Increasing the open face area will reduce the fume hood's efficiency.
  6. Do not place electrical apparatus or other ignition sources inside the fume hood when flammable liquids or gases are present.
  7. A fume hood should not be used for storing chemicals unless the fume hood had been designated for storage.

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.

Etching Grounds

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.

Stop outs

Alcohol: slightly toxic.

Rosin: slightly toxic by inhalation.

Asphaltum: toxic by skin contact, possibly causing skin cancer and skin irritation. Wash carefully after use.

Aquatint

Rosin can cause respiratory problems during this process because of the fine dust produced when it is shaken onto the plate. Wear respirator.

Acid

Zinc and copper plates are etched with nitric acid of varying strengths. Copper plates can also be etched with Dutch mordant or iron perchloride.

Hazards:

  1. Concentrated acids are highly corrosive to the skin and eyes. Nitric acid etching can release highly toxic nitrogen oxides, especially if a large plate is being etched or the acid solution is too strong.
  2. During the preparation of Dutch mordant, highly toxic chlorine gas is released. Dutch mordant is not to be used in the stainless steel fume hood. See instructor. Chlorine gas is highly irritating to the eyes and mucous membranes of the respiratory system. Potassium chlorate can be explosive in contact with organic materials such as rosin.
  3. Nitric acid etching on zinc releases small bubbles of hydrogen gas. If the surface being bitten is large and/or a strong nitric acid solution is being used, the solution might get hot enough to cause the ground or hydrogen gas to catch fire.
  4. Nitric acid etching of both zinc and copper plates can release highly toxic nitrogen oxides. This is especially true when large plate areas are being etched or the acid solution is too strong. This can be very hazardous since nitrogen oxide gases are highly irritating to the lungs. Single heavy exposures (especially if you see a brownish-orange gas) can cause pulmonary edema and possibly death. Long-term effects of exposure to nitrogen oxides include emphysema and chronic bronchitis. Note that nitrogen oxides do not have good odor-warning properties, and effects might not show up for several hours.
  5. Iron perchloride (ferric chloride) is moderately irritating to the skin . It is also moderately toxic by ingestion and inhalation.

Precautions:

  1. It is wise to wear gloves when handling and mixing concentrated acids and when handling plates in acid baths.
  2. The acid baths and preparation of acid solutions should be done in a fume hood. Ordinary respirators are not sufficient protection against nitric acid fumes. In case of excessive emission of nitric acid fumes during etching, add sodium bicarbonate to neutralize the acid.
  3. If the acid bath gets too hot, carefully remove the plate from the bath and cool it with cold water. Wear gloves.
  4. Acid mixture - always add acid to the water. Usual mixtures are: Normal bite - 8 parts H20 to 1 part acid; Strong bite - 4 parts H20 to 1 part acid. Avoid spiking baths (adding acid to tray), as this makes for an inconsistent bath.

Photoetching

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.

Hazards:

  1. Methyl cellosolve acetate is a highly toxic solvent, causing blood and kidney damage and nervous system damage. It is hazardous both by skin absorption and inhalation.
  2. Xylene is highly toxic by inhalation, and moderately toxic by skin contact and absorption.

Precautions:

  1. Wear butyl rubber gloves and goggles when handling the photoresist and photodeveloper. Do not wear contact lenses.
  2. Use photoetching materials in a fume hood or have very good dilution ventilation. In some cases you might require an organic vapor respirator if a fume hood is not available.

Relief Printmaking

Woodcuts and linocuts

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.

Precautions

  1. Always cut in a direction away from you, with your free hand on the side or behind the hand with the tool.
  2. Solvents which are used during cleanup are skin irritants. Wear gloves.

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.

Silkscreen Supplies and their Hazards

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.

Silkscreen Inks

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

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

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

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.

Resist and Blockout

Stencils

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.

Hazards:

  1. Adhering fluids for lacquer-type emulsions usually contain acetates, ketones and alcohols, and are moderately toxic by inhalation. They are also slight to moderate skin irritants. Film removers often contain aromatic hydrocarbons and are highly toxic by inhalation.
  2. Isopropyl alcohol is slightly toxic by inhalation. It presents no significant hazard by skin contact, but is an eye irritant.
  3. Isopropyl alcohol, adhering fluids and film removers are all flammable.

Precautions:

  1. Adhering fluids and isopropyl alcohol require normal general ventilation. They both have good odor warning properties.
  2. Some artists also use the adhering fluids to remove the film. This is less hazardous than using film remover, even though it may take a little longer.
  3. Obey normal fire prevention rules.

Photo Stencils:

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.

Hazards:

  1. Ammonium dichromate is moderately toxic by akin contact, causing ulcers and allergies. Inhalation of the powder can cause severe respiratory irritation, ulceration of the nasal septum, and respiratory allergies. It is a suspect carcinogen. Ammonium dichromate is also flammable.
  2. Silver nitrate is moderately corrosive to the skin and highly corrosive to eyes. Caustic soda, used as developer with this sensitizer, is highly corrosive to skin and eyes.
  3. Hydrogen peroxide is a slight skin irritant in diluted form. In concentrated form it is hazardous.
  4. Diazo sensitizing solutions are eye irritants by direct contact.
  5. Carbon arcs are highly hazardous, giving off metal fumes, nitrogen oxides, and ozone, all of which are severe lung irritants. In addition, the ultraviolet light produced is harmful to the eyes.
  6. Enzymes can cause skin allergies in some people. Inhalation of the powder can cause asthma. Bleach is a moderately toxic skin irritant and is highly toxic by inhalation if sprayed.

Precautions:

  1. Wear gloves and goggles when mixing and using photostencil solutions and when cleaning the screen.
  2. Do not use carbon arcs. Instead use a photoflood or sun lamp.
  3. Presensitized emulsions are a good choice. for making photostencils since it is not necessary to handle the hazardous ammonium dichromate.

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URL: http://cool.conservation-us.org/bytopic/health/victoria.html
Timestamp: Monday, 24-Nov-2008 16:07:10 PST
Retrieved: Friday, 24-Nov-2017 03:55:28 GMT