Determination of mercury content in skin lightening cosmetics products using a direct mercury analyser

The objective of this study, the first study of its kind conducted in Morocco, was to evaluate mercury concentrations in skin whitening products using the MA-3000 direct mercury analyser.

Mercury is widely recognised as one of the most dangerous elements to human health. Despite the well-known risks, skin whitening creams and soaps containing this toxic substance continue to be produced and purchased, especially in the Middle East, Asia, and Africa. This practice constitutes a global public health issue due to the widespread distribution of these products. In Morocco, these items are commonly found in beauty stores and boutiques, which are frequently used for their skin-lightening effects.

Twenty-nine samples of skin whitening products were collected from the local market in Rabat. The mercury content in these products was measured using the MA-3000 direct mercury analyser, in accordance with USEPA Method 7473. The method has a Limit of Detection (LOD) of 0.002 µg/g and a Limit of Quantification (LOQ) of 0.008 µg/g, ensuring the reliability and validity of the results. Moreover, the method demonstrated a recovery rate of 105%, further confirming its accuracy and precision. The mercury concentration was measured in micrograms per gram (µg/g). This unit is equivalent to parts per million (ppm), a unit commonly used to express very low concentrations.

The analysis revealed that 25 out of 29 samples contained mercury concentrations ranging from 1.01 µg/g to 10.47 µg/g, exceeding the 1 µg/g limit established by the Minamata Convention on Mercury. Conversely, 4 samples showed no detectable traces of mercury.

This study reveals the concerning presence of mercury in skin-lightening products available on the Moroccan market. The continued circulation and frequent use of mercury-containing creams and soaps, both in Morocco and in other developing countries, underscore the pressing need for strengthened regulatory frameworks and stricter control of hazardous substances in cosmetic products. These findings raise significant public health concerns, particularly for vulnerable populations who may be unknowingly exposed to toxic levels of mercury through daily use of skin-lightening products.