The Basics of Using a Kiln Safely

By
Beth Peterson
Beth Peterson
Beth Peterson is a pottery expert, sharing her knowledge about producing pottery on the wheel, as well as handbuilt ceramic sculpture, and the Raku firing technique of pottery making. She also teaches mask making to children and adults. Beth has over 30 years of experience crafting with clay.
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Updated on 12/08/19
Women placing pottery in a kiln

Lukas Olek / Getty Images

Kilns can be quite safe to use, even at home, when you follow some basic precautions. Due to the high temperatures, firing a kiln releases volatile compounds into the air, many of which are toxic. You will need to use these safety procedures and tips to prevent injury.

  • 01 of 05

    Personal Protective Gear

    Even when a kiln has more than adequate insulation, its outer surface can become hot enough to seriously burn someone if touched or brushed against with bare skin. The following personal protective gear is essential:

    • Kiln mitts or gloves: These should be worn when handling any part of a kiln (other than a control panel) while it is firing or cooling. Even after power or fuel has been turned off, kilns will remain hot for hours. Do not open or touch until fully cooled.
    • Dark glasses: Glasses from a safety supply house are recommended when looking into kiln spy holes. These protect your eyes from the radiant heat. Regular sunglasses are inadequate for this purpose and may actually melt. Protective glasses may also allow you to see your cone packs more clearly.
  • 02 of 05

    Vent Kilns

    All kilns should either be outdoors or properly vented to the outside. Every firing releases gases which will be irritating to the body. They may also be toxic or even lethal if safety measures are not followed.

    • Vent kilns properly. Follow the kiln manufacturer's instructions and use a licensed heating, ventilation, and air-conditioning (HVAC) contractor for proper installation.
    • HVAC contractors have the equipment to accurately test the adequacy of the system’s ventilation. Light a match in front of the kiln's hood. If the system is working properly, the hood draw should blow the match out.
    • Always turn on your kiln hood or vent prior to loading to prevent ceramic glaze dust exposure.
  • 03 of 05

    Kiln Gases

    Gases emitted by kilns when firing can cause respiratory problems. This possibility is heightened if it is a reduction or salt firing kiln. Some specific gases to be aware of are:

    • Carbon dioxide is given off during any fuel-burning firing. Overexposure leads to blood oxygen levels falling, a decrease in hearing and pulse rate, and a rise in blood pressure.
    • Carbon monoxide is released during reduction firing. Exposure can lead to headaches, dizziness, fatigue, and drowsiness. Carbon monoxide can be lethal.
    • Sulfur dioxide can be released when firing soluble metal salts. It is a strong lung irritant.
  • 04 of 05

    Kiln Firing

    Firing fuel-burning kilns can be more of an art than a science. If you are interested in learning to use a fuel-fired kiln, find a class or a nearby potter who will teach you the ropes. Fuel-fired kilns need to be attended during the beginning of their warm-up period until the flashpoint of the fuel (the temperature at which the fuel ignites) has been reached.

    Electric kilns should be fired according to the manufacturer’s instructions.

    Continue to 5 of 5 below.
  • 05 of 05

    Electric Kiln Installation

    Install electric kilns in accordance with local electrical and fire safety codes and in accordance with manufacturers' suggested installation instructions. Installation must be performed by a qualified electrician. To do otherwise may invalidate your insurance coverage. For used kilns, contact manufacturers for installation instructions.

    Tips

    • Do not allow children near kilns.
    • Do not operate a kiln in a wet area.
    • Do not open the lid or door when a kiln is operating.
    • Do not try to unload a kiln until the outside of the kiln is cool to the touch and the pieces can be easily touched by hand.
    • Kilns should be given at least one foot of clearance. Do not put anything on top of a kiln.
    • Do not unplug or plug an electric kiln in unless the circuit is off. Turn all switches to "off" before loading or unloading the kiln. Always unplug the kiln while making any repairs.