“Trace” refers to very low levels of impurities/contaminants in a finished cosmetic product. Trace presence is likely to stem from impurities of natural or synthetic ingredients, the manufacturing process, storage and migration from packaging. Due to the ubiquitous nature of certain heavy metals that are otherwise prohibited, several countries such as the US, Canada, Germany and the EU recognise the non-intended presence of these prohibited substances in small quantities as “trace”.