The agency posted the RFI in the Federal Register on August 29, allowing for a 60-day input period.
"Quartz accounts for the overwhelming majority of naturally occurring crystalline silica and is present in varying amounts in almost every type of mineral," MSHA officials said, noting that because there are large amounts of dust generated by mechanised mining and milling, miners are at risk of exposure to those elevated levels.
The longer-term dangers of quartz exposure via respirable dust can include chronic obstructive pulmonary disease (COPD), along with pneumoconiosis in various forms: silicosis, coal workers' pneumoconiosis, progressive massive fibrosis and rapidly progressive pneumoconiosis.
The RFI includes an examination of an appropriately reduced permissible exposure limit, potential new or developing protective technologies, and/or technical and educational assistance.
