You want to determine the amount of crystalline silica in a sample...
The health risks of respirable crystalline silica
Under the new regulation that came into force in January 2021, manufacturers, particularly in the construction sector, must now measure the exposure of their employees to crystalline silica dust.
Indeed, crystalline silica in respirable form has been declared as a carcinogenic substance.
The SWeRFcs methodology: beyond bulk analysis
SWeRFcs stands for Size Weighted Respirable Fraction of crystalline silica.
Unlike standard bulk analysis, the SWeRF method estimates the specific fraction of particles that are respirable—meaning they are small enough to reach the pulmonary alveoli. As a specialized SWERF laboratory, FILAB calculates this fraction by weighting particle size distribution (determined via laser diffraction) against the respirable penetration curve defined in EN 481. This provides a realistic assessment of the actual health hazard posed by materials such as quartz, cristobalite, or tridymite.
FILAB: your expert SWERF laboratory for the determination of crystalline silica
To meet these needs, FILAB Laboratory proposes an analytical method called “SWERF” allowing to measure the respirable fraction weighted by the size of the crystalline silica present in the sample.
For this, we use several analytical techniques:
Our SWeRF characterization services
Liquid Laser Particle Size Analysis to determine the particle size distribution of the sample. The applicable reference document for this analysis is ISO 13320:2020.
Helium Pycnometry to measure the real density.
X-Ray Diffraction between 10 and 90° to determine the crystallographic nature of the phases present and a dosed addition of Quartz.
Our other analysis services
Quantitative analysIs of crystalline silica in materials (XRD, FTIR)
Support réglementaire pour la classification CLP, les dossiers REACH et la conformité à la directive cancérogènes.
Respirable fraction measurements (SWeRFcs) for powder/mineral manufacturers.
Études R&D : optimisation des procédés pour réduire la poussière respirable
Why perform a crystalline silica analysis using the SWeRF method?
It is a widely used indicator for:
- Assessing the actual hazard of materials containing silica.
- Determining whether a product should be classified as carcinogenic under the CLP regulation.
- Helping manufacturers document their REACH dossiers and manage their regulatory obligations.
FAQ
The SWeRF (Size Weighted Respirable Fraction) method makes it possible to estimate the fraction of particles of a material that are respirable, i.e. capable of reaching the pulmonary alveoli.
SWeRFcs is the application of the SWeRF method specifically to crystalline silica (quartz, cristobalite, tridymite). It indicates the proportion of crystalline silica that is actually respirable and therefore relevant for health risk assessment.
Because respirable crystalline silica is classified as a 1A carcinogen at European level, the SWeRF method makes it possible to assess the proportion of crystalline silica that can actually penetrate the lungs and thus determine whether a product should be classified as hazardous according to the CLP regulation and REACH obligations.
Construction materials (cements, concretes, mortars).
Industrial minerals (sands, fillers, mineral fillers).
Metallurgy, foundry, glassmaking, ceramics.
Chemistry and production of technical powders.
- Compliance with REACH and CLP regulatory requirements.
- Securing safety data sheets (SDS).
- Objective risk assessment for operators.
- Promoting product value by proving their relative safety.
Yes, it is highly recommended for any mineral mixture or powder containing crystalline silica, including sands, cements, clays, talcs, and mineral fillers. It is the most effective way to determine if these materials meet the 0.1% concentration threshold that triggers carcinogenic classification.
Beyond regulatory compliance, SWERF characterization is a valuable tool for R&D. It allows manufacturers to analyze how different grinding or processing steps affect the generation of respirable dust, enabling the development of safer products and more efficient industrial processes.
FILAB combines ISO 17025 accreditation with a multidisciplinary approach, housing all necessary techniques - XRD, Laser Diffraction, and Helium Pycnometry - under one roof. This ensures full traceability, technical synergy, and robust results for your REACH or CLP regulatory dossiers.
