Enameling Safety Issues You Should Know About
Enameling involves the firing and melting of suitable glasses onto and into metals for decorative effects. It is done at fairly high temperatures, from 1200°F (649°C) to a high kiln temperature of 1700°F (927°C) or so.
The primary dangers involve dusts, the particle size of the enamel used, the chemical constituents of the enamel (older enamels frequently contain lead and other toxic metal oxides and chemicals), the infrared radiation of the kiln and sundry opportunities to burn oneself. Enamelists in factories have even been killed by scalds from water when molten enamel was dumped into it (Tver and Anderson 98).
Older copper enamels were lead-based, and could thus lead to lead poisoning. Many current enamels imported from overseas are still made with lead, which also poses reproductive risks. Rossol notes that “lead stored in your bones from previous exposures re-enters the blood stream during pregnancy” (“Pregnancy and the Crafts Professional” 21). Lead affects reproduction from conception to after the birth of a child; specifically, lead absorbed by the fetus may affect mental capacity, growth rate, and hearing, as well as leading to “decreased ability to maintain a steady posture, and neurobehavioral developmental problems” (Rossol, “Pregnancy” 23). According to Rossol, “new studies indicate that antisocial behavior may be associated with lead exposure” (“Pregnancy” 23). Enamels may also contain toxic metals such as cadmium, antimony, nickel, manganese, chromium, and cobalt. Enamelists in industry may be exposed to the following: amyl acetate, arsenic, barium and compounds, benzene, bismuth and compounds, n-butyl acetate, carbon disulfide, cellosolves, cerium, chromium compounds, cresol, fluorides, hydrogen chloride, hydrogen fluoride, lead, manganese compounds, nickel compounds, phtalic anhydride, sodium and potassium hudroxides, titanium, toluene, xylene, zinc compounds, zirconium compounds (Kinnersly 379-380). McCann notes that the Nuclear Regulatory Commission has banned the use of radioactive uranium oxide for coloring enamels (Health Hazards 58) – if you do find a stockpile of, say, Thompson’s burnt orange or forsythia enamels which contain uranium, don’t use them, because they’re radioactive. Gum tragacanth, which is sometimes used to coat the plate so the enamel will adhere to the surface, may cause respiratory allergies if sprayed (McCann, AB! 465). Potassium carbonate (potash), an ingredient in slurry for dipping or spraying enamels onto metals, will burn your skin (McCann, AB! 465). “Gum turpentine,” which is mixed with enamel powders and other ingredients to create a painting medium for enamels, poses the same risks as turpentine: to use McCann’s terms, it’s “moderately toxic” if you touch it, inhale it, or swallow it, and it “can cause irritation, allergies and kidney damage” (AB! 465). Please see under “Etching,” for additional risks involved in Champlevé enameling, where you etch the design and inlay the enamel. Firing enamels can produce toxic fumes or smoke.
Cataracts from long-term exposure to infrared radiation in kilns. Inhalation of dusts.
Standard issues of working heights, repetition, reach in production situations.
See “Fire Safety Rules” and “Fire Safety.” Kilns can be a fire hazard , and you can burn yourself on the hot enamel, too. See also under “Soldering” if you’re soldering cloisons for cloisonné. Solvents may also be flammable.
Inhalation or ingestion of enamel powders, which may also irritate your skin. Inhalation, ingestion or skin contact with materials used to apply enamels. Inhalation of fumes or smoke produced during firing.
Safety Precautions to Use
Rossol notes that mechanical methods such as pumice, steel wool, wire brushes etc., are the safest for cleaning metals to receive enamels (239). McCann agrees, and adds “a coarse sponge and liquid dishwashing detergent” to the list (AB! 463).
Use application methods that raise less dust, “such as wet charging damp enamel using spatulas, or dipping and painting enamels that are mixed with resin and solvents (here the hazards are primarily the solvent vapors)” (Rossol 239). McCann says it a bit better in Artist Beware!: “Whenever possible, brush or dip enamels instead of dusting or spraying” (465). Be very careful about dust exposure: consider making a ventilated glove box.
Rossol notes that “spray products containing solvents are the most hazardous and should be used with local exhaust ventilation” (239). Use a spray booth and make sure kilns have adequate ventilation; as McCann notes, “this can be done by placing the kiln on a bench immediately in front of a window containing an exhaust fan, or by placing a canopy hood directly over the kiln” (AB! 466). McCann suggests using infrared goggles (shade numbers 1.8 to 3) when firing, as heated enamels, and the interior of the kiln, emit IR radiation which can, over time, cause cataracts (Health Hazards 58). Rossol suggests that you “provide sufficient space around kilns …to work safely and comfortably” (241).
Wear protective clothing, including gloves, good work shoes etc. Don’t wear synthetics or loose clothing that can easily catch fire, and keep ice or iced water around for treating minor burns should they occur. “Leave shoes and work clothing in the studio to avoid taking dusts home. Wash work clothes frequently and separately from other clothes” (Rossol 241).
Enamelists have been injured by dusts and chemicals that arose from their clothes after work (Tver and Anderson 98). Rossol notes that enamelists using leaded enamels should “arrange regular blood tests for lead” (243). If your enamels spill, wet them before cleaning up, to avoid spreading dust everywhere.
Store your solvents safely, in “self-closing safety cans,” and put “waste solvents or solvent-soaked rags in approved self-closing waste cans that are emptied each day” (McCann, AB! 466). McCann also suggests that “leftover enamels can be combined and used as counter enamels for the reverse side of the piece, thus eliminating the need to dispose of the residual enamel” (AB! 467).
Don’t lick your brushes to form a point on them, and don’t eat, drink or smoke in the studio-it’s very easy to accidentally ingest some enamel powder and poison yourself. Rossol, writes: “Never locate (enameling) studios in or near living or eating areas” (Rossol 241). Get MSDS sheets on your enamels.
Avoid enamels colored with toxic metals like cadmium. Don’t use hydrofluoric acid to finish enamels, as it is extremely dangerous-see “Titanium/Niobium Anodizing” for more details on this really scary substance. If you want a matte finish on your piece (which is what hydrofluoric acid does), ammonium bifluoride paste is not quite so terrifying, but “is still highly toxic by skin contact and ingestion, since it produces hydrofluoric acid in solution” (AB! 467), so wear goggles and gloves.
Substitution Options to Reduce Risk
Use lead-free enamels. Use epoxies (they have their own dangers) or other inlay methods. Enameling done well and carefully is quite safe.
- Kinnersly, Patrick. The Hazards of Work: How to Fight Them. London: Pluto Press, 1973.
- McCann, Michael. Artist Beware! Rev. ed. New York: Lyons and Burford, 1992.
- Health Hazards Manual for Artists. 4th rev. ed. New York: Lyons and Burford, 1994.
- Rossol, Monona. The Artist’s Complete Health and Safety Guide. 2nd ed. New York: Allworth Press, 1994.
- “Pregnancy and the Crafts Professional: Hazards and Effective Precautions for Staying Safe While You’re Pregnant.” Crafts Report September 1997: 20-23.
- Tver, David, and Kenneth Anderson. Industrial Medicine Desk Reference. New York: Chapman and Hall, 1986.