Venting the kiln of fumes is essential to producing quality ware. All products fired in electric kilns contain organic materials that make carbon monoxide and other fumes when they are burned. Fumes released may contain sulfur oxides, hydrogen fluoride and metal vapors, depending on the products fired. Carbon monoxide and other fumes can affect the color and properties of the fired product if they are not removed from the kiln earlier in the firing.Venting fumes from the room is essential to creating a quality work enviroment. OSHA has set standards for carbon monoxide exposure of 35 ppm (parts per million) for long-term exposure and 200 PPM for short-term exposure. Independent testing has shown that fumes near the kiln can exceed 200 PPM near the kiln during the firing of greenware. This can cause headaches, fatigue, sore throats and nausea.
Proper Kiln venting will prevent:
Unburned carbon in bisque ware that causes crazing, pinholes or blisters during glaze firing.
Dulled surfaces and cloudy colors.
Weak colors in red-orange-yellow glazes.
Color migration caused by glaze fumes depositing on nearby ware.
Cones which bend improperly due to inadequate oxygen.