Evaluation of quality parameters and heavy metals in selected cosmetic products in Sri Lankan market

Abstract

Cosmetic products play a significant role in personal care routines worldwide, including in Sri Lanka. Concerns regarding the quality and safety of products have grown due to the potential presence of harmful chemicals and inconsistent product formulations. This study focuses on the analysis of selected cosmetic products commonly available in the Sri Lankan market, assessing their quality attributes, and detecting possible toxic metal contaminants. Four brands of skin creams sold in Sri Lankan market have been investigated for a period of one year (June 2021-June 2022). All analyses were done in triplicates for each sample. Samples have been selected under three categories, sun creams (S1-S4), moisturizing creams (S5-S8) and whitening creams (S9-S12). These samples were obtained from four brands. pH, Non-volatile matter, water content and toxic metals were analyzed. All physicochemical parameters were analyzed according to the test methods given by the SLSI. Heavy metals were analyzed using ICPMS. Range of pH at 27±2oC in selected creams was (5.7 ± 0.09 to 7.8 ± 0.14). According to the specification for skin creams (SLS743:2021), the acceptable range of pH at 27±2oC in creams is 4.5- 8.0. pH value of all the skin care cream samples were statistically in acceptable pH range. Nonvolatile matter at 105oC percent by mass in selected creams was (9.90 ± 0.08 to 24.90 ± 0.07). According to the specification for skin creams (SLS743:2021), acceptable Non-volatile matter at 105oC, percent by mass (minimum value) of skin creams is 15. Nonvolatile matter of S1, S2, S3, S4, S6, and S7 were 10.6. ± 0.11, 9.5 ± 0.42, 11.2± 0.08, 14.20 ± 0.34, 9.90 ± 0.08 and 11.10 ± 0.06 respectively and all six samples were not complied with the acceptable (minimum) level. The water content percentage by mass in selected creams was (70.40 ± 0.59 to 87.60 ± 0.53). According to the specification for skin creams (SLS743:2021), acceptable Water content, percent by mass (maximum value) of skin creams is 85. The water content of all samples was below the acceptable (maximum) level except S4 sample (87.60 ± 0.53). Some of metal concentrations were tested under metal analysis, Aluminium 9.2 ± 0.18 - 224.9 ± 3.24 mg/kg, Zinc 2.90 ± 0.09 – 19866.7 ± 1423.21 mg/kg, Calcium 88.1 ± 5.2 – 2647.8 ± 87.1 mg/kg, Potassium 15.4 ± 0.16 – 3645.8 ± 4.97 mg/kg, Sodium 142.3 ± 2.9 – 7960.2 ± 845 mg/kg), Molybdenum 0.33±0.01 - 3.09 ± 0.06 mg/kg, Magnesium 9.10 ± 0.04 - 250.00 ± 168.13 mg/kg, Vanadium 0.34 ± 0.01 - 2.41 ± 0.06 mg/kg. Some metals were not detected, and some results were below LOQ level. According to the specification for skin creams and lotions (SLS743:2021), acceptable maximum value of Lead, Arsenic, Mercury, Cadmium concentration in skin creams are 10 mg/kg, 3 mg/kg, 1 mg/kg and 3 mg/kg respectively. As, Cd, Pb, and Hg level were below the recommended limits according to the SLS standard. According to the results obtained from this study, all the tested samples were in acceptable quality and as the recommendation; further research can be conducted to determine the chemical concentrations which can damage the function of skin.