Measuring Respirable Crystalline Silica (Quartz) from Powdery Materials through Sedimentation and X-ray...

Area of Science:

• Occupational Health and Safety
• Analytical Chemistry
• Materials Science

Background:

• Respirable crystalline silica (quartz) exposure poses significant health risks to workers and end-users of powdery products.
• Effective and cost-efficient methods are needed to quantify low quartz content in materials like cement, concrete, and plaster.
• EU regulations mandate classification and labeling of products containing harmful substances above specific thresholds.

Purpose of the Study:

• To present a reliable method for analyzing respirable dust and quartz content in powdered construction materials.
• To meet regulatory requirements for product classification and labeling concerning crystalline silica.
• To support the development of safer powdery products with reduced quartz exposure potential.

Main Methods:

• Separation of the respirable dust fraction using liquid sedimentation.
• Gravimetric analysis of the separated dust.
• Quantitative determination of crystalline silica content via X-ray diffractometry.

Main Results:

• The method accurately quantifies quartz in powdery materials, with a quantitative limit of determination at 0.01 wt.%.
• Achieved a linear range of 0.02-10 wt.% with a high Pearson correlation coefficient (0.99).
• Demonstrated an accuracy of 82% and repeatability of 11% for the analysis.

Conclusions:

• The developed method effectively analyzes respirable quartz in construction products, fulfilling regulatory and industry needs.
• This analytical capability aids in ensuring worker safety and compliance with EU regulations (e.g., EU Regulation No. 1272/2008).
• The method supports the creation of less hazardous powdery products by enabling precise quartz concentration measurement.