Elements in lipstick material

Main text Cosmetics and personal care products are widely used globally. Although toxic elements are banned as intentional ingredients, they may exist as impurities either as contaminants in the raw ingredients, or as by-products of the manufacturing process. These toxic elements can accumulate in the body over time and cause adverse health effects. Different regions around the world have established relevant guidelines and regulations to safeguard the safety of consumers. Therefore, there is a need for metrology institutes to strengthen their measurement capabilities in this area. The supplementary comparison APMP.QM-S17: Elements in Lipstick Material was coordinated by the Health Sciences Authority, Singapore. Four measurands (arsenic, cadmium, mercury and lead) with maximum limits stated under the Association of Southeast Asian Nations (ASEAN) Guidelines on Limits of Contaminants for Cosmetics were chosen. Only one key comparison in the area of cosmetics (CCQM-K106: Lead, Arsenic and Mercury in Cosmetic Cream) was organised by the National Institute of Metrology (NIM) China in 2013. Hence, it was timely to organise another comparison in this area that covered cosmetics but in a different matrix. The study sample (lipstick) offered different analytical challenges as compared to the cream material used in the previous comparison. Moreover, it enabled National Metrology Institutes/Designated Institutes (NMIs/DIs) that did not participate in CCQM-K106 to demonstrate their measurement competencies. Seven institutes participated in the comparison for arsenic, nine for cadmium and lead, and eight for mercury. All participating NMIs/DIs employed microwave-assisted acid digestion for sample dissolution. Inductively coupled plasma mass spectrometry (ICP-MS) and sector field ICP-MS (SF-ICP-MS) were the two most commonly used instrumental techniques. Results of all participating NMIs/DIs were evaluated against the supplementary comparison reference value (SCRV). The SCRV and associated uncertainty were determined from results of NMIs/DIs that participated in the supplementary comparison using methods with demonstrated metrological traceability. For cadmium, mercury and lead, the median was used as estimator of the SCRVs. For arsenic, the arithmetic mean was used as estimator of the SCRV. The SCRVs (± expanded uncertainty) for arsenic, cadmium, mercury and lead (in mg/kg) were 4.188 (± 0.237), 2.0670 (± 0.0171), 2.732 (± 0.147) and 10.406 (± 0.080), respectively. The degree of equivalence and its associated uncertainty were calculated for each submitted result. Most participating institutes were able to demonstrate their capabilities in the determination of elements in lipstick material. Participating NMIs/DIs that have successfully participated in APMP.QM-S17 have demonstrated measurement capabilities in determining mass fraction of transition elements and metalloids/semi-metals, in mass fraction range from 0.1 mg/kg to 25 mg/kg in cosmetic matrices with high organic contents, such as lipstick. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).