Because encaustic does not require solvents, it is a relatively safe medium to work in. The three safety concerns for encaustic are:
With adequate ventilation and proper working temperatures (between 180 and 200°F) encaustic is non-toxic. In many studios, working next to a window exhaust fan and having a source of fresh air coming in from another part of the studio, gets rid of fumes adequately. It is important to create cross-ventilation in your workspace, because even at recommended working temperatures, wax fumes can be irritants, causing headaches and coughing. Wax fumes become more and more concentrated, and therefore more harmful, at higher temperatures. We recommend using a thermometer and avoiding any temperature over 240 degrees. Warning signs that your wax is too hot include an acrid odor and smoking. For more information on ventilation, see our ventilation technical sheet.
Heating tools and hot wax can cause burns to the skin. Wear an apron to protect you from spills. If you do not have a sink, keep a bucket of cool water in your studio. If you are burnt, bring the temperature of the burn down immediately by immersing the burn in cool (not cold) water. Do not peel wax off your skin. It will seal the burn from oxygen, and pealing it can tear the skin. Keep the burn immersed for at least half an hour, unless you have a burn kit, in which case apply the dressing once the burn has been cooled down in the water. If the burn is serious, seek medical help.
Commercially made encaustics should have an ASTM labeling for toxicity. Paint in general, and toxic colors specifically, should not be ingested. Clean your hands before eating, and do not eat or drink near your work area. Pigment does not get absorbed into the skin, but barrier creams do help make the paint easier to wash off your hands. The ASTM labeling ensures that the specific pigment is stable and will not decompose or volatilize at working temperatures.
Solvents are toxic. Heating solvents make them even more toxic. Avoid using solvents of any kind with encaustic.