Asbestos: facelift for standard NF X43-050

Twenty-five years ago, France banned asbestos, and the first major asbestos removal projects began: remember Jussieu, in Paris! With them came a whole arsenal of methods for measuring fiber content in the air and precautions to protect operators. Among them was standard NF X43-050, which describes the protocol for determining the dimensions, nature, and concentrations of asbestos fibers present in the air. It is a reference text, judging by the many regulatory texts that cite it.

But that was twenty-five years ago... "Today, sampling, preparation, and analysis techniques have evolved. In addition, the occupational exposure limit (OEL) has been lowered to 10 fibers per liter, which has changed the scale of measurements taken in the air. The standard, which dated back to 1996, therefore needed to be revised," explains Caroline Lhuillery, project manager at AFNOR, who supported professionals in drafting the updated standard. This was completed in July 2021, with a new version now available in the AFNOR collection.

The changes relate to the following points: sampling and sample preparation, transmission electron microscopy, camera resolutions, filters and membrane porosity, mass flow versus volume flow, field blank, sampling system tightness, fiber classification, etc. In addition, the standard had to be updated to bring it into line with a standard published in the meantime. the NF X43-269 standard of December 2017 on air quality in the workplace, which deals more specifically with membrane filter sampling to determine the concentration of fibers using microscopy techniques.