Substitution of a hazardous art material or process by one that is safer should be the first precaution that is tried. For children under the age of 12, it is mandatory to use non-toxic art materials. However, substitution will also work for older students and professional artists.
One of the basic types of substitution is to use water-based materials instead of solvent-based ones. For example, silk screen printing with solvent-based inks is one of the most hazardous art processes and requires expensive ventilation systems to work safely. Switching to water-based silk screen printing minimizes the health risks.
Similarly acrylic and water color painting are safer than oil painting which requires mineral spirits or turpentine. This is particularly a consideration in high school painting classes where exposures in a class of twenty students doing oil painting could be very hazardous because of the large amounts of solvents used. A fan exhausting 3000 cubic feet of air per minute would be required for every cup of turpentine or paint thinner evaporated in a one hour class period. Instead, use acrylic, water color, or similar water-based paints.
If switching to water-based materials is not possible, then try less toxic solvents. The least toxic solvents are ethyl alcohol (sold as denatured alcohol), isopropyl alcohol, rubbing alcohol, acetone, and odorless mineral spirits or paint thinner. You can often use these solvents to replace more toxic solvents like methyl alcohol, lacquer thinners, toluene, xylene, and turpentine. Note that flammability should also be considered when making substitutions. Acetone, for example, is one of the least toxic solvents, but is extremely flammable.
Other examples of less toxic substitutes are cadmium-free silver solders, fluoride-free fluxes, asbestos-free materials, crushed walnut shells, or glass beads instead of sand for abrasive blasting, and lead-free glazes and enamels.
Changing a process can sometimes reduce exposure. For example, brushing or dipping materials is safer than spraying them since this eliminates inhalation of the particulates. Wet working methods also reduce the risk of inhaling dusts. Other examples of process substitution include the use of moist clay, liquid dyes, and wet grinding techniques.
Avoid cancer-causing materials because there is no known safe level of exposure to these substances. Of course, the lower the exposure, the lower the risk.
Finally, remember that substitution takes time to work. I have had many artists tell me that they tried substitutes such as water-based silk screen inks, but the substitutes do not produce good results. Usually, artists have tried the water-based inks a few times in the same way that they used the solvent-based inks. Using the same techniques will not necessarily give good results. Substitutes often have very different properties from the original material, particularly if you are switching from solvent-based to water-based materials. For example, no painter would try to use acrylics or watercolors with the same technique used for oil painting. Therefore, allow time to experiment to find the proper way of using the substitute.