María Virginia Fernández González
Pharmacist and member of the research group Soil Science and Geopharmacy at the University of Granada.
Our group has been studying talc as a mineral raw material for pharmaceutical and cosmetic use since the 1990s. We focus on the study of the pharmacopeial quality of talc for its use in pharmacies and cosmetics, combined with the mineral and geochemical quality of this raw material.
In our research, we have been able to verify that some of the talcum powders commercialized in the 1990s contained asbestos fibers (amphiboles), a material that presents a small particle size and a fibrillar morphology, which can be toxic according to the scientific literature. Our study techniques were mainly microscopic, X-ray diffraction, and specific pharmacopeia tests.
In recent research conducted by our group (since the 2010s), we have been able to verify that talcum powders for pharmaceutical and cosmetic use that are marketed in pharmacies and large stores in Mediterranean countries of Latin origin (Spain, France, Italy, Portugal) and others such as Norway, Morocco, and even on Amazon, no longer contain asbestos. However, they may still present some mineral impurities such as chlorites and carbonates (calcite and dolomite) or quartz; these are non-carcinogenic minerals but sometimes appear in appreciable amounts that cause the samples to fail pharmacopeial tests. These minerals have been detected using advanced techniques such as X-ray diffractometry (XRD) and scanning electron microscopy (SEM), associated with microanalysis (EDX), all without forgetting the tests of the European Pharmacopeia. Additionally, we studied the content of heavy metals (ICP-MAS).
In the detailed observation of the morphology and composition of talc particles by SEM-EDX, it was found that, sometimes, there are talc mineral fibers, but they are not elastic like asbestos and their composition is typical of the talc mineral. Furthermore, they are exfoliative and of little consistency; on the skin, they will easily crumble.
As we said, we have not detected asbestos-like fibers.
In our opinion, the main issue today is to ensure that talc classified as cosmetic contains at least 90% talc mineral (with a maximum of 10% of the main non-carcinogenic impurities). [That is,] it should have mineral purity.
Additionally, we suggest that the industry should carry out exhaustive quality control on all talcum powders before they are commercialized in pharmacies or cosmetics, to comply with the tests included in the pharmacopeia.