Levels of Hydroquinone, Selected Heavy Metals (Hg, Pb, As) and Chemical requirements in Some Skin Lightening Creams Sold in Mbarara Municipality

Abstract

In this study, Skin-lightening creams commonly sold in Mbarara municipality were analyzed for chemical parameters (pH, thermal stability and fatty substance content), total hydroquinone, Lead, Mercury, and Arsenic contents. Total heavy metal content was determined by atomic absorption spectrophotometry. The levels of hydroquinone were determined using High Performance liquid chromatography (HPLC). All the creams showed detectable mean levels of mercury, ranging from 0.07±0.01ppm to 0.33±0.01ppm. Only 26.31% of the creams showed detectable levels of lead and 15.79% creams recorded detectable levels of arsenic. The mean levels of hydroquinone ranged from 0.54±0.02% to 4.47±0.02%. All the creams passed the thermal stability and fatty substance content tests. However, all the creams had very low pH values below the recommended 4.5- 8.5 pH ranges by Uganda National Bureau of Standards (UNBS). The levels of mercury, arsenic and lead in the samples were less than the UNBS, European Union and US Food and Drug Administration’s acceptable limits. Only 84.2% of the cream samples analyzed contained hydroquinone levels higher than the recommended WHO limit of 2%. The use of such creams may lead to serious health hazards. While the low concentrations of heavy metals detected in the cream samples analyzed do not pose any potential risk to consumers, repeated application of these creams may cause a cumulative effect over prolonged exposure. The low pH values may cause skin irritations.  Therefore, the community needs to be sensitized on the implications of using skin lightening creams and UNBS should conduct periodic analysis to ascertain the levels of hydroquinone, heavy metals, and chemical requirements of skin lightening creams sold in Uganda as well as encourage manufacturers to state the exact bleaching agents in their creams.