Kiln Room Safety

  • Refractory materials, bedding sand and mould materials all contain Crystalline Silica, which is a serious health hazard. (see Terms: Refractory and Crystalline Silica)
  • Dust masks/respirators MUST be used when loading or unloading ANY kiln.
  • ALWAYS wear dust mask/respirator to divest a casting from a Plaster/Silica mould.
  • Divesting should ALWAYS be done in under the ventilator in the Plaster Room and thoroughly cleaned up when finished.
  • Used/Fired mould material lying around will NOT be tolerated.
  • Face mask, gloves and fire-resistant jacket MUST be used when “charging” a kiln during a firing. (See terms: “Charging”)
  • When drying moulds kilns should ALWAYS be vented (with small sliver of kiln shelf). This prevents build up of steam—which can burn you when you first open the kiln if not vented—and will increase the life of the elements by reducing oxidization from water vapor and heat.
  • Preheat glass before charging a mould. This will reduce risk of thermal shock, which can cause glass to explode and injure you. It will also speed up the casting time and reduce chance your mould will fail.


  • Charging: to load glass into a mould or furnace, typically while at firing temperature.
  • Crystalline Silica: also knows as “free” silica, crystalline silica is present in all quarts sand and dirt and it’s “open” crystalline structure causes it to stick to lung tissue when inhaled. Exposure can lead to silicosis, lung fibrosis caused by the inhalation of dust containing silica. The condition is irreversible, chronic and progressive.
  • Refractory: a substance that resists heat.