Respirable Cristobalite

**Semantic type:** Hazardous or Poisonous Substance

**Definition:** A naturally occurring, crystalline metal found in volcanic rocks. Heating of silica generates respirable cristobalite, which is primarily found in refractory silica bricks. Inhalation exposure to respirable cristobalite causes chronic silicosis, emphysema, lymph node fibrosis and is associated with an increased risk of developing lung cancer. (NCI05)