Investigation of heavy metal risks in liquid foundation products

Liquid foundations are widely used to conceal blemishes and create an even skin tone, but concerns remain regarding contamination by prohibited heavy metals. In this study, inductively coupled plasma mass spectrometry was used to measure heavy metal levels in commercial liquid foundation products and to investigate the possible source of thallium contamination. Most detected prohibited elements were present within the limits of China’s Safety and Technical Standards for Cosmetics (2015). Nevertheless, two batches contained thallium above the reference limits. A high detection rate was observed among products formulated with zinc oxide, indicating that thallium may be introduced through zinc oxide raw materials or their manufacturing process. The authors recommend tighter supplier qualification and raw material monitoring, adoption of thallium removal technologies, and independent testing. They also call for exposure-based health risk models and more specific safety thresholds for vulnerable groups, including pregnant women and children, to strengthen cosmetic safety management.