On the one hand, this view is correct. According to Jeff Zamek, a longtime potter, ceramic consultant and author of the book, Safety in the Ceramics Studio, "The statistical information, and behind that the anecdotal information, states that potters as a group do not come down with aluminosis, silicosis or other respiratory diseases as a result of exposure to the materials most commonly used in this industry." However, he notes, the improper use of ceramic materials can be detrimental to potters' health. Additionally, hazards such as working around hot kilns, handling sharp ware, lifting heavy objects and performing repetitive motions often pose problems for potters who do not take the right precautions. There are also environmental and economic considerations-for instance, what happens to excess glaze that is dumped down the drain, and how much glaze is wasted in a given week or month through improper spraying procedures?
To ensure a safe and healthy working (and living) environment, everyone in the industry must explore these and other issues. Armed with the appropriate knowledge and protective equipment, potters will then be free to focus on the most important aspect of their business-making pottery.
Although Zamek believes that ceramic materials themselves are not inherently dangerous, he points out that many airborne particles and vapors can cause respiratory irritation and eventual illness if they are inhaled at high concentrations and/or over long periods of time. The best approach is to control these materials and vapors at the source, before they enter the studio, but this isn't always feasible. To be on the safe side, Zamek advises that potters should wear a respirator whenever mixing clays or glazes, working in or walking through dry material storage areas, cleaning kiln shelves or cleaning the studio.1
Safety glasses and goggles can protect against airborne particles and debris, and infrared varieties can also shield potters' eyes from ultraviolet and infrared radiation when looking into a firing kiln. Rubber or latex gloves can be worn to protect against skin irritants when handling dry or wet raw materials. More important, however, are the heavy-duty, heat-protective gloves used to prevent burns and cuts on potters' hands and arms. "Cuts and burns from reaching into the kiln when it's too hot or when a glaze is razor sharp are some of the most common injuries experienced by potters, yet they can easily be avoided," Zamek says.
"It's not enough just to get the excess glaze out of your studio; you have to contain it," says Joe Koons, senior technical advisor for Laguna Clay Co. in City of Industry, Calif., and a longtime ceramic artist and tile maker. "Overspray can easily be 1/4 to 1/2 of the amount of glaze actually sprayed on a piece, which is a tremendous amount of waste. A well designed spray booth is highly efficient, and the amount of glaze it recovers can easily and quickly offset the initial cost of the equipment."
Koons advises that potters look for a system that maximizes glaze recovery while minimizing maintenance and cleaning requirements. "Cleanliness is everything-it is directly related to your profits because it helps you avoid color contamination when working with different colors, and it also aids in glaze recovery. Start with a clean spray booth and clean up when finished, and use a different filter for each color," he says.
Kiln venting systems protect potters against these substances by removing them from the studio. Some systems use an adjustable vent mounted over the top of the kiln, which can be raised and lowered as needed to simplify kiln loading and unloading. Others systems pull fumes out from the bottom of the kiln and allow fresh air to enter from the top of the kiln to ensure even heat distribution. Which design is better?
"A very useful tool in making a decision is to call the kiln vent manufacturer or the ceramics supplier who sells the product and ask for the phone numbers of customers who have purchased a kiln venting system in your area," Zamek says. "Most potters will gladly tell you the good and any deficient points of the venting system they purchased. Ask to visit their studios to see the kiln vent in operation."3
Zamek doesn't think so. "Unfortunately, many people don't know enough about ceramic toxicology, and they easily become scared by reports about certain exposures and hazards that are based on extrapolations of industrial exposures to these materials over long durations in fields such as silica mining. But there is very little data and few health studies available on how potters use ceramic raw materials, or their relative risk," he says. "If potters want to err on the side of caution and invest extra money in an air filtration or purification unit for their studios, they certainly can, but in most cases it's statistically and anecdotally unnecessary."
Doug Van Sickle of Van Sickle Environmental Systems, Sherman Oaks, Calif., who has been a studio potter for nearly 30 years, disagrees. "Exposure to silica dust is cumulative, and a respirator simply can't provide enough protection," he says. "I've seen many people mix glaze in the same room where they handle their other processes, and then take their respirator off after the glaze has been mixed into the water. But the dust is still in the room, so they'll be breathing that in. Dust is also created when you're sweeping the floor, or even just trimming, and many people don't adequately protect themselves during these operations. Using an air purifier can remove silica and particulate matter from the facility, and can significantly reduce the level of risk."
According to Van Sickle, almost all suspended particulate matter in the air has a positive static electric charge and, due to its extremely minute size, remains in the air for five to six hours. A single purifier unit generates billions of negative ions that attract these positively charged particles, regardless of their size. These particles clump together until they have sufficient weight to fall from the air, where they can be sponged or wet-mopped away.
Another air-cleaning option is ambient-air filtration, whereby all of the air in a room circulates through one or more filters that collect the dust particles. According to Dave Bubb, director of representative sales for Trion Inc., Sanford, N.C., the drawback to an ambient-air system is that the dust must first become airborne. "This means that workers can be exposed to the dust before it gets to the air cleaner, and you never get 100% or even near perfect collection, because you're always adding dust to the space. But you can significantly reduce the amount of dust in the air by 60-90% or more with these systems," Bubb says.
An even better option is source control, in which dust collection systems are placed near the process and collect the dust at the source, before it becomes airborne in the facility. However, Bubb notes that such systems can be impractical due to space or operation constraints.
"If you're wedging clay or throwing, take frequent breaks. Don't wedge up 50 pieces of clay at a time; wedge up 20 and then do something else and come back to wedging later," he advises. "Alter your work cycle so you're not getting into a situation where you're repetitively doing something for over an hour. If you're lifting kiln shelves, make sure you're lifting them correctly to avoid back injuries. If you're reaching into the kiln, wear protective gloves to avoid cuts or burns."
Zamek also advises that potters request material safety data sheets (MSDSs) on all materials used in their studios, and notes that any company would be wise to compile a "safety booklet" that is required reading for all new employees.
"Avoiding problems is largely a matter of common sense-it's deceptively simple," Zamek says.
Editor's note: This article is intended to be a brief overview of basic health and safety issues and some of the equipment available to address these issues. It should not substitute for in-depth research or professional advice, and Ceramic Industry does not endorse any of the equipment or suppliers mentioned. More comprehensive health and safety information can be found in Jeff Zamek's book, Safety in the Ceramics Studio (Krause Publications, Iola, Wis., 2002, $25.45), available from Jeff Zamek/Ceramics Consulting Services, 6 Glendale Woods Dr., Southampton, MA 01073. The book can also be ordered through Ceramic Industry's online bookstore.