Image: ©Alireza Naseri

Respirable crystalline silica; Health-based recommended occupational exposure limit

Crystalline silica is a mineral that is abundant in most rocks, sands and soils.  When crystalline silica is cut or crushed, dust that contains respirable crystalline silica particles is released into the air. These particles can be inhaled deep into the lungs and cause diseases such as silicosis and lung cancer.

For respirable crystalline silica there is no safe exposure concentration below which no adverse health effects occur. The approach to protect workers is aimed at reducing the possible consequences of occupational exposure as much as possible. In collaboration with the Nordic Expert Group (NEG), the Dutch Expert Committee on Occupational Safety (DECOS) has estimated which concentrations of respirable crystalline silica correspond to set cancer risk levels. The exposure concentration that corresponds to the target risk level is 0,00038 milligrams of respirable crystalline silica particles per cubic meter (m3) of air.  The exposure concentration that corresponds to the prohibition risk level is 0,0363 mg/m3.