Abrasive blasting, commonly known as sandblasting, involves forcibly projecting a stream of abrasive particles through compressed air or steam against a surface to change its quality or to remove contaminants. Silica blasting sand contains high levels of crystalline silica--which can cause pulmonary fibrosis (silicosis) after exposure through inhalation and is considered a lung carcinogen--and constitutes approximately 63% of all abrasives used in abrasive blasting. Other abrasives, including specular hematite, are recommended as alternative blasting agents. Due to the health risks associated with using blasting sand in the abrasive blasting process and the lack of toxicity data on alternatives to blasting sand, the National Institute for Occupational Safety and Health (NIOSH) proposed testing blasting sand and alternative abrasives to characterize their associated toxicity. (Abstract Abridged).