Ceramics Studio - Safe Work Practice Manual

Safe Work Practices Manual

Fine Arts Studio - Ceramics Studio W890

 

In addition to reading this SWP Manual, students are also required to read and acknowledge a studio-specific Hazard Assessment

Please Note: This SWP manual is not intended to provide detailed instruction of processes and techniques.  It is not a substitute for attending technical demonstrations and taking notes. 

 

General

  • Regularly review the Safe Work Practices Manual for each area you are working in- this is an important resource.

  • In addition to reading the SWP Manual, students are required to read and acknowledge studio-specific Hazard Assessments and, if applicable, attend studio demonstrations. 

  • Know the material you are working with and read the SDS labels and information sheets to ascertain the proper safety precautions you should take.  

  • Wear the appropriate Personal Protection Equipment when working in the workshops. For example, you may need to wear a respirator and work in a ventilated environment based on the information provided with this material. 

  • All materials, supplies, and works in progress must be stored appropriately with the understanding that W840 supports all studio programs. 

  • If you are unsure about which tool to use or how to use it consult the safe work practice manual, a Technician, and your Instructor before starting. 

  • All placement of art outside the 8th floor must be approved by OH&S through the completion of the Art Placement Form. This form is on the OH&S website of the university and must be completed five days prior to the installation of your work. 

  • Wear personal listening devices in all Studio Classrooms when working after class hours as other students may need the quiet to concentrate. You may be asked by your instructor not to use any personal listening devices during class hours. If this is the case, please follow the directions given you. 

  • Be aware of the impact of your work on the work of others in your studio classroom. 

  • Doors to studios must be kept closed- do not prop open. Do not give away the code to studio doors. 

  • All containers must be labeled, do not use food or drink containers for any controlled substances such as paint thinner, glue, patina solutions, etc.

Housekeeping

  • Do not block fire exits and fire-fighting equipment.  

  • Keep aisles, walkways and stairs clear.  

  • Store materials in designated storage areas or in your locker or studio space. 

  • A clear uncluttered passageway must be maintained in storage areas; do not leave anything sticking out beyond the front edge of racks and shelving. 

  • Remove projects immediately after they have been graded to open up space to make more work. 

  • All storage must be cleaned out at the end of each term. Look for signs and heed your instructor’s directions about portfolio pick-up at end of term.  All articles left behind will be removed and thrown out. 

  • Wash charcoal dust and paint off table tops at the end of each work period as studios are shared spaces. 

  • Keep your studio facilities and classrooms clean and tidy.  

  • Respect your work and the work of others. 

  • Be aware of the impact of your work on the work of others in the workshops. 

  • Keep all disposal bins tidy with no projecting articles. 

  • Clean up spills immediately in order to avoid a slipping hazard. 

  • Clean and put away all tools and materials when job is done, and at the end of each workday. 

  • Wear the appropriate Personal Protection Equipment when working in Art Studios and Workshops. 

  • Sweep floors, equipment, counters, and tables after completion of tasks and at the end of every workday. 

  • Avoid causing trip hazards with extension cords and air hoses.

Each person in the School of Fine Arts is responsible and accountable for his/her own safety performance. It is important that each person understand that he/she is also expected to work in a manner that will not cause harm to any other person within the University community. Art materials can affect the body in various ways. There are three major routes of entry: inhalation, ingestion and skin contact. 

  1. Inhalation: The most common ways that foreign substances enter the body are from vapors, fumes, dust, gases or mists that can be inhaled into the respiratory system. The substances may damage the nose, mouth, and upper respiratory tract, lungs or be absorbed into the bloodstream and travel to other organs in the body.
  2. Ingestion: Substances may be accidentally or willingly ingested through the contamination of food, drinks, cigarettes and hands. These substances may affect the mouth, throat and/or stomach or be absorbed into the bloodstream. 
  3. Skin Contact: Substances may attack or destroy the natural protective barriers of the skin, damaging the skin itself, and enabling toxic chemicals to enter the bloodstream, where they are carried to various organs of the body.

It is imperative that eating and/or drinking do not occur in any work area.

All students are required to participate in the Safe Work Practices. This includes participation in training and instructional workshops, reading the information sheets that accompany the training sessions, and signing off on their understanding of the information before beginning work in the studio facilities.

HOURS OF OPERATION

Once training requirements have been met Students have access to and are allowed to work in their Studio Classroom any time the University is open, as long as safety and working alone policies are followed (see page 9: Working Alone Policy).  

Students with training are permitted to work in the Sculpture Facilities (W840) according to the schedule which corresponds to the hours when Technicians are on duty. This schedule is posted on the Workshop doors.

It is the responsibility of every person in the area to be aware of his or her surroundings, which in turn will create a safe working environment. Particular attention should be paid to the following: 

  1. Telephone: located inside the studio at the exit. Emergency numbers are posted on each telephone.
  2. First Aid Kits: located in each area and are clearly marked. These are for emergency first aid procedures only. Do not use supplies for any other use.
  3. Eye Wash Stations: located in each area and are clearly marked. Eye wash stations are tested weekly, by the department Safety Representative.
  4. Fire Extinguishers: located in every working area.
  5. Safety Data Sheet binders: located in studios where the Department supplies controlled products to support instruction (see below)

The following materials and substances cannot be used in student projects: ammunition or explosives, flammable liquids, biohazardous material or waste. 

WHMIS information sheets and proper labeling according to WHMIS regulations must accompany all controlled products.  WHMIS training is provided by OH&S, as a student you must complete the WHMIS Online Training Course offered through OH&S on Moodle.  

Safety Data Sheets (SDS) are provided in all studios for all controlled products supplied by the Department to support instruction.

Controlled products for your personal use must also have appropriate WHMIS labels and accompanying SDS information sheets. 

  • All containers must be labeled (including harmless items like distilled water). The label should contain the proper name of the material (i.e. Turpenoid, Varsol) and the name of the user if appropriate, a statement of hazards should also be listed. 

  • Do not use material from unlabeled containers. The need for adequate labeling extends far beyond the immediate individual user, as they may not be present if the container spills or breaks.  

  • It is important that no unidentified materials are left in unlabeled containers, jars, or bottles. Proper labeling is important since it is difficult and costly to dispose of unlabeled chemicals. 

Each individual has the responsibility for seeing that waste chemicals are safely collected, identified and stored for disposal, and that anyone involved is fully advised of the need for any special methods or facilities for proper disposal.  

Handling of Waste

Chemicals are everywhere: they can be found in animals, plants and water as well as in many commercially available products including medicines, detergents, paints, and foods. The risk may be low, but present. In order to keep the risk to a minimum, all chemical waste must be disposed of properly. Once a material is declared a waste, the first responsibility for guiding its proper disposal rests with the worker. He or she is in the best position to know the degree of hazard posed by the material they have used and must provide sufficient information to fit it into the correct channel for disposal. 

Some Acids and Bases:

The following acids and bases have been approved for drain disposal while flushing drain with water, if the pH range is between 3 and 11 (prior to draining).  

Sulfuric acid, hydrochloric acid, phosphoric acid, sodium hydroxide, potassium hydroxide. 

Any chemical which qualifies as a hazardous waste must be collected for proper disposal through OH&S.  A waste may be designated as a hazardous waste if it meets one of the following criteria:

  1. Acute hazardous waste is a waste which has been found to be fatal in humans in low doses or, in the absence of data on humans, has been found to have, in laboratory animals:
    • An oral LD50 (Lethal Dose of 50% of the test subjects) of less than 50 mg/kg.
    • An inhalation LC50 (Lethal Concentration) of less than 2 mg/l, or
    • A dermal LD50 of less than 200 mg/kg.
  2. A waste is hazardous if it contains any of the toxic constituents listed in the regulations.
  3. A waste is hazardous if it exhibits any of the following characteristics:
    • Ignitability
    • Corrosivity
    • Reactivity
    • Toxicity*
    • Sharpness
  4. Each Studio generating chemical waste in the Department has a designated location within the room for waste accumulation.
  5. Hazardous Waste Disposal containers are located by the sinks in most studios. As well sharps containers are located in various studios for the safe disposal of glass, knives or saw blades.

All workplace hazardous materials must be identified and disposed of according Provincial Regulations. No substance that may affect the Environment, Plant, Animal, or Human Life can be disposed of in the garbage or flushed down the sewer system. Consult with a Technician before you act.

Effective ventilation is the best method for controlling contaminants generated and released into the studio atmosphere. There are two basic types of ventilation: general and local exhaust. Local exhaust ventilation is required when working in: 

Painting Studio W817
Metal Shop W840 
Advanced Studio W823
Kiln Room W890D 
Wood Shop W840A
Clay Mixing/ Slurry Room 890A 

Spray Booths are located in W840 + W520, use these when spraying fixative to drawings or when using spray paint. If the contaminant is highly toxic or large amounts of the toxic material are produced a respirator must also be worn.

As a result of the hazard assessment performed by the Technical Staff of the Department of Art working alone is not permitted if it can be avoided. 

All work planned outside of times when Technicians are on shift must be done with another student. Any Students found working alone in any studio area will be asked to leave the facility by Security personnel. The buddy system should now be enforced in all of the following workspaces:  W817, W823, W869, W871, W890, A, B, C +D, W520, L804, W844, W842, and W748 A-K. Excerpt from Art Safety Policy (1992); 

In addition, students working after hours are required to have a buddy present. A buddy is another student who is enrolled in and cognizant of the School of Fine Arts Safety Policy. The buddy must remain within the same studio at all times. 

The University of Lethbridge now has a Working Alone Safely Login that informs Security that an individual is working alone on campus. All Faculty, Staff, and Students are asked to use this system to login and out with security when they are on campus after regular hours.

The Working Alone Safety Login can be access through Uleth Safe app

This policy was developed through the guidelines found in the booklet “Working Alone Safely: A Guide for Employers and Employees” as developed by Alberta Human Resources and Employment. 

Fire

In the event of fire, please phone the following EMERGENCY number immediately: 911 or 329-2345. 

Action to be taken (R.E.A.C.T.): 

  1. Remove those in danger. 
  2. Ensure the room is closed. This step will confine a fire to the room of origin. This will also prevent the spread of smoke and toxic gases. 
  3. Activate the fire alarm. This will occur automatically with smoke and heat detection equipment. There is nothing wrong with calling the Fire Department for assistance and providing details of the fire. 
  4. Call the Fire Department. 911 or 329-2345. A person should be designated to call the Fire Department even though the building alarm system is automatically connected to the Fire Department. 
  5. Try to extinguish or control the fire. If there is any doubt in the mind of the person(s) attempting to extinguish the fire regarding their ability to do so, then confine the fire to the room of origin by closing the door. 
  6. Evacuate. 
  7. Keep people from re-entering the building until directed to do so by the Building Fire Warden of Campus Security. 

Air Contamination

Should you smell any foreign or unrecognized odors, please phone the following EMERGENCY number immediately: 329-2345. 

What to report: 

  1. The location of the odor. 
  2. Time the odor was first apparent. 
  3. Any physical symptoms experienced by persons in the affected area, ie. headache, feeling of nausea. 
  4. Any information suggesting the odor's origin. 

Open any windows or doors to attempt to dilute the polluted air with fresh outside air. Stay out of the affected area and await further instruction by safety personnel. 

Chemical Spills

Should a chemical spill occur in your area please phone the following EMERGENCY number immediately: 329-2345. 

What to report: 

  1. The location of the spill and any evidence that tells what the chemical could be, ie. an empty bleach bottle lying on the floor indicating the substance may be bleach. 
  2. Any odor, ie. a strong smell of ammonia. 
  3. Any visible chemical reaction that may be occurring, ie. a substance bubbling on the floor. 

When proper personnel have been notified, no one should enter the contaminated area. If an odor is present, open a window and post a guard outside the odorous area keeping untrained persons away. NO ATTEMPT SHOULD BE MADE TO CLEAN UP THE SPILL. Await arrival of emergency personnel.

Personal Protective Equipment

There are times when exposure to toxic materials cannot be prevented, and as such any person working in the area must wear the appropriate personal protective equipment. Contact the Technician, your Professor, or OHS for assistance in selecting the correct PPE. It is not only important that the correct PPE is worn but that the equipment fit properly. For instance, respirators must have a mask to face seal and facial hair prevents a tight seal. 

  • CSA approved eye protection must be worn when working in W840 and elsewhere when the activity demands it. 

  • Prescription lenses and sport glasses are not an acceptable substitute for proper, required Industrial safety eye protection. 

  • Contact lens should not be worn in Art Studio Environments. Contact lens may trap or absorb particles or gases causing eye irritation or blindness. 

  • Eye protection should fit properly, with or without prescription lens.  

  • Return glasses to the proper storage rack face up to avoid scratching lens. 

  • In this storage rack you will find a variety of styles- pick the one that fits you best. 

  • There are two common types of hearing protection: earplugs or earmuffs. 

  • One or both types must be used when working in W840 and W890B (grinding room) and at all times when equipment is operating. 

  • These studio workshops are high noise areas and hearing protection is a must even if you are not the one making the noise. 

  • Hearing loss, which normally occurs over an extended period of time, is one concern in high noise areas, but the immediate effect of high noise areas is fatigue- when we are tired we make mistakes, some of which could be serious. 

  • Students are required to wear good solid shoes when working in any Studio. Leather shoes with closed toes are best. These protect your feet from most substances used in studios- for example, spills: photo chemicals, acids, and paints. Open toed sandals should not be worn in any studio, and are not permitted in W840 or W890

  • If you have safety boots wear them and if you know you are going to live in these studios buy some safety footwear. 

  • Employees must wear safety footwear in the above areas and in the performance of the majority of their duties. 

  • Dust masks most be worn in W840, W840A, and W890 A, B, and C when the activities in these areas are dust producing. 

  • Local ventilation and air extraction equipment must be utilized in the above studios depending on the nature of your activity. 

  • Spray Booths are located in W840 + W520, use these when spraying fixative to drawings or when using spray paint.  

  • If the contaminant is highly toxic or large amounts of the toxic material are produced a respirator must also be worn. 

Due to the variety of studio activities you must consider further personal protection that may take many different forms such as leather gloves, nitrile gloves, leather/chemical aprons etc. 

Generally the following rules apply when working in studios and shops: 

  • All rings, bracelets, necklaces, and watches should be removed. Long hair must be tied firmly back and tucked in. Short sleeves should be worn when working in the wood shop and shirttails must be tucked in. 

  • If you bend over nothing should fall away from your body.  

  • When working with metal or hot processes long sleeves should be worn, and clothing should be made of natural fibers such as cotton or wool. Synthetic fibers, such as spandex or polyester, melt onto the skin and can cause severe burns. 

  • Unlike in the woodshop, shirttails should not be tucked in when working with hot processes. Do not roll up sleeve cuffs, and pocket flaps should be closed. You want any hot particle to be able to pass through your clothing and not to become trapped against your skin. 

  • Shorts and open-toed shoes or sandals should not be worn in the other studios. You must keep in mind that many of the products you will use are absorbed through the skin, and could be corrosive. 

  • Wash hands and arms thoroughly before leaving the studios after working with potentially hazardous material and before eating, drinking, smoking, etc.

Care and Maintenance 8th Floor Exhibition Spaces

These spaces will operate on a one-week rotating schedule, and it is your responsibility to schedule your time in the space. At the end of the exhibition period the following procedure must be followed:

  • Get the paint kit from technicians. In this kit you will find the following supplies: 
    Paint Brush, Roller sleeve and handle, pole sander and sand paper, Extension Pole, Wall Filler, putty knife, Tape, White Latex paint, Paint Tray and drop cloths, brush, and roller spinner. 

  • Lay down the drop cloths tight to the walls, if necessary tape these down with painters tape. They should overlap each other by 24”. 

  • Remove all nails and fastening devices, with pole sander lightly sand the walls, smoothing out the dimple caused by your nails. 

  • Prepare a small quantity of wall filler and apply leanly to all nail holes. 

  • When this is dry lightly sand the walls again taking care to make the walls as smooth as possible. 

  • Stir your paint well and only use the latex paint provided. 

  • Fill the paint tray with a moderate quantity of paint working only on the drop clothes. 

  • With a paintbrush first apply a brush coat on all filled areas, then carefully cut in the edges of the walls. Do not paint concrete, floors, baseboards, or electrical outlets. 

  • Once you have finished cutting in use the roller to apply a light even coat of white latex paint to the walls. 

  • After you have completed the painting scrap excess paint from roller into tray, with a brush, clean paint tray returning excess paint to paint can. 

  • Roll or fold up your drop cloths and sweep the area before returning paint kit to W840. 

  • Return all used painting equipment to W840 and carefully remove the roller sleeve and thoroughly rinse it in the sink making sure all paint is washed out of roller and paintbrush. 

  • Using the paint spinner in the sink fit roller sleeve over end of spinner and spin roller to remove excess water. Stand damp roller sleeve upright for finally drying.  

  • Using the paint spinner, place brush handle into clamp and spin to remove excess water. Smooth out the bristle while brush is still damp and lay brush flat to dry or hang on wall over sink. 

Ceramics Studio

  • Doors to W890 must be kept closed. Do not prop open, do not share code.  

  • Clear, uncluttered passageways must be maintained in studio area. 

  • All materials, supplies, and works in progress must be stored appropriately with the understanding that storage facilities must be user maintained.  

  • All storage areas must be cleaned out at the end of each term. Look for signs and heed your instructor’s directions about portfolio pick-up at end of term.  All articles left behind will be removed and thrown out by technical staff. 

  • Wear personal listening devices in all Studio Classrooms when working after class hours. Other students may need the quiet to concentrate. 

  • You may be asked by your instructor not to use any personal listening devices during class hours. If this is the case please follow the directions given you. 

  • Know the material you are working with and ask for the SDS on all materials you purchase. Read the SDS labels and information sheets to ascertain the proper safety precautions you should take.  

  • All containers must be labeled; do not use food or drink containers for controlled substances. 

  • Be aware of the impact of your work on the work of others in the studio. 

  • If you are unsure about which tool/material to use or how to use it consult the safe work manual, a technician, or your instructor before starting. Report any equipment damage or malfunction to your instructor or a technician. Do not use any equipment on which you have not been trained. 

  • All plaster processes must stay out of the clay area- do not bring tools or processes from one studio to the other. 

  • Wear the appropriate Personal Protection Equipment when working in the studios, including proper footwear. NO OPEN TOED SANDALS IN THE STUDIO. Consider aprons or lab coats to protect your clothing. 

  • Leave your work area clean and empty for the next person; store your work on the ware carts, NOT on the tables or wheels. Ensure equipment, tools and buckets are clean and put away after use. 

  • Clay, or water with clay in it (i.e. used while working or cleaning) MUST NOT go down the drain. Dispose of clay-water in the bucket in the sink. Likewise, rinse your hands and tools in that bucket to remove excess clay, and then do a finishing rinse in the sink.

The main health concern when working in the ceramics area is dust. Inhalation of dry materials, including dry clay, can seriously damage your lungs. Avoid excessive dust exposure. 

  • All clay bodies and many glazes contain some free crystalline silica which can scar your lung tissue and cause irreversible loss of breathing capacity. 

  • Keep work areas clean by wet-wiping; clear scraps away before they dry out. Place clay scraps in appropriate buckets or bins. 

  • Clean studio floor with a wet mop. 

  • Thoroughly clean all wheels, tables, tools and equipment after use and wash up any spills, splatters, or trimmings from the floor. 

  • DO NOT EAT OR DRINK IN THE WORK SPACE

  • Wash hands thoroughly before eating or drinking. 

Many glaze materials are hazardous. Know what you are using and read the SDS. If you cannot find adequate information about a material, assume hazardous potential. 

  • Learn distinctions such as: iron oxide is not toxic but iron sulphate is. 

  • Individual sensitivities to hazardous materials vary and can be affected by medications and health histories as well as genetics.  

  • Protect yourself with proper handling of glazes, PPE and studio clean-up procedures. 

To avoid repetitive strain, use good work habits.   

  • Adjust wheel height, bench height, and wedging board heights to enable you to work with your back straight. 

  • Keep your back straight when lifting heavy materials or equipment. 

  • Take rest periods with hand flexing and muscle stretching exercises if working for long periods of time. 

  • Modify technique or equipment to avoid uncomfortable postures or movements. 

  • Keep clay at a reasonable thickness for the piece, and aim for consistent wall thickness. Thin sections will dry more quickly than thick, thereby shrinking faster and causing cracking or breaking. Slow the drying of thin sections by wrapping in damp paper towel. 

  • Even and slow drying is best. Allow your piece to dry draped with a plastic sheet or other appropriate material. Do not leave it in the sun or use a blow dryer or heat gun to speed up drying. 

  • Clay must be completely dry before it is kiln fired. Wet or damp clay will explode as the moisture rapidly heats and expands. 

  • Join pieces securely by scoring and using joining slip. 

  • Avoid trapped air in the clay- air bubbles will cause your piece to explode in the kiln. Wedge re-used or reclaimed clay thoroughly, and if making an enclosed form be sure to include a vent hole. 

  • Avoid dust- do not dry-sand clay; keep work areas clean. 

  • Do not contaminate clay tools with plaster as plaster will cause the clay to explode in the kiln. 

  • Keep bisqueware clean, and handle with clean hands- glaze will adhere unevenly (if at all) to spots where hand lotion or the oils from your skin create a resist. 

  • Use a damp clean sponge to remove all dust from the surface of the piece before glazing. 

  • Leave the underside and the bottom ¼” of your piece UNGLAZED so it does not fuse to the kiln shelf during firing.

  • Use wax emulsion where resist is required. Allow to dry thoroughly before glazing. 

  • Glazes must be well-mixed. Even while using the glaze, re-mix every few minutes to prevent settling, whether in a bucket or a small container. 

  • Pour, dip, or brush the glaze as appropriate for each piece. Transfer glaze from large buckets to smaller containers when using a brush to apply. 

  • Apply two layers of glaze at maximum- too thick glaze will peel and crack as it dries, and may flake off your piece. 

  • Remove unwanted glaze by first scraping with a small metal tool, then wiping the remainder away with a damp sponge. 

The following is a list of common materials used in ceramics, either in clay or glazing. Many, but not all, are used in our ceramics studio.

Lead Compounds

(Lead Chromate, lead monosilicate, lead sulfide, Litharge) Skin toxicity not significant. Inhalation toxicity high. 

Both acute and chronic ingestion or inhalation can cause lead poisoning. Inhalation is more of a problem than ingestion. Lead affects the gastrointestinal system, red blood cells, neuromuscular system, other common effects include weakness, headaches, irritability, malaise, pain in joint and muscles, liver and kidney damage, and possible birth defects. 

Lepidolite - Skin toxicity moderate, Inhalation toxicity high. Skin contact may cause burns, Inhalation and ingestion may cause respiratory and gastrointestinal irritation. Chronic inhalation may cause silicosis.

Manganese Carbonate and Manganese Dioxide - Skin toxicity not significant. Inhalation toxicity high. Chronic inhalation may cause manganese poisoning, a serious nervous system diseases resembling Parkinson's disease. Early symptoms include apathy, loss of appetite, weakness, spasms, headaches, irritability, etc.

Nepheline Syenite: - See Felspathoids below

Potash: - Skin toxicity moderate. Inhalation high. Alkalis are corrosive to skin and eyes. Inhalation causes severe irritation and possible pulmonary edema.

Potassium Dichromate - Skin toxicity moderate. Inhalation toxicity high. Skin contact may cause irritation, allergies, and skin ulcers. Chronic inhalation may cause perforation of nasal septum and respiratory allergies. Causes cancer in animals, suspected human carcinogen. 

Soda Ash - Skin toxicity moderate. Inhalation high. Corrosive to skin and eyes. Inhalation causes severe irritation and possible pulmonary edema.

Talc - Skin toxicity not significant. Inhalation high. Inhalation of talc may cause lung scarring. Chronic inhalation may cause silicosis if silica is present, or asbestosis, lung cancer and mesothelioma if asbestos is present.

Tin Oxide - Tin oxide dusts are irritating to eyes and nose and cause lung changes as shown by chest x-ray, but no ill effects.

Vermiculite - Inhalation toxicity high. Asbestos contaminated, chronic inhalation may cause asbestosis, lung cancer, etc. 

Water Glass - (sodium silicate) May cause skin and respiratory irritation. 

Wollastonite - May cause skin, eye and respiratory irritation. 

Zircon (zircopax) - Inhalation toxicity high. Causes nodules under the skin from skin contact and in the lungs from inhalation. Chronic inhalations may cause silicosis.


Hazards of Glaze Ingredients and Colorants

Antimony Oxide - Inhalation toxicity high. Skin toxicity moderate. 
Skin contact may cause severe lesions, including ulcers. Acute ingestion or inhalation may cause metallic taste, vomiting, diarrhea, severe irritation of mouth and nose, slow shallow breathing, and pulmonary congestion. Chronic exposure may cause loss of appetite and weight, nausea, headache, sleeplessness and later liver and kidney damage. May vaporize during firing.

Asbestos - Skin toxicity slight. Inhalation toxicity high. Carcinogen.
Inhalation may cause asbestosis (a form of lung fibrosis), lung cancer, stomach and intestinal cancer.

Barium Carbonate - Skin toxicity slight. Inhalation toxicity high. 
May cause skin, eye, nose and throat irritation. Inhalation or ingestion may cause barium poisoning with symptoms of heart irregularities, intestinal spasms, and sever muscle pains. Chronic poisoning is most likely. 

Chrome Oxide - Skin & Inhalation toxicity moderate. Suspected carcinogen. 
May cause skin and respiratory irritation, causes cancer in animals and possibly in humans. 

Chrome Yellow (lead chromate) - Skin toxicity moderate. Inhalation high. Carcinogen. 
Skin contact may cause allergies, irritation and skin ulcers. Chronic inhalation may cause lung cancer, lead poisoning, etc. 

Clays - Inhalation toxicity high. 
Chronic inhalation can cause silicosis, a disease involving severe lung scarring. 

Cobalt Carbonate - Cobalt Oxide: Skin toxicity slight. Inhalation moderate. 

Colemanite - Skin and Inhalation toxicity moderate. 
Caustic to skin, eyes, nose and throat, may cause skin ulceration. 

Copper Carbonate (malachite) - Skin toxicity slight. Inhalation moderate. 
May cause skin allergies and irritation to skin, eyes, nose and throat. 

Cornish Stone - Skin toxicity slight. Inhalation high. 
Acute inhalation may cause lung irritation, acute ingestion may cause gastric intestinal circulatory and nervous system problems. 

Feldspathoids - Skin toxicity moderate, Inhalation toxicity high. 
Skin contact may cause burns. Inhalation and ingestion may cause respiratory and gastrointestinal irritation. Chronic inhalation may cause silicosis. 

Flint - Skin no significant hazards, Inhalation toxicity high. Chronic inhalation may cause silicosis. 

Iron Chromate - Skin toxicity moderate, Inhalation toxicity high, carcinogen. 
Skin contact may cause skin irritation, allergies, ulcers. Chronic inhalation may cause lung cancer, respiratory allergies and irritation. 

* https://www.southtexascollege.edu/academics/visual-arts/safety/ceramics.html