4 Va. Admin. Code § 25-40-760
Silica sand or other materials containing more than 1.0% free silica shall not be used in abrasive cleaning equipment unless exposed persons are provided with self-contained respiratory equipment.
§§ 45.1-161.3, 45.1-161.294 and 45.1-161.305 of the Code of Virginia.
Derived from VR480-05-1.2 § 5.5, eff. July 19, 1989.