Analysis of Heavy Metal Content in Conventional and Herbal Toothpastes Available at Maltese Pharmacies

Andrew Vella,Everaldo Attard

doi:10.3390/cosmetics6020028

Abstract

Although toothpastes are considered as topical cosmetics that are not normally ingested, it is evident that they may contribute to the introduction of heavy metals and xenobiotics through buccal and gastrointestinal absorption. The purpose of this study was to determine the potential presence of metals and polyphenols in conventional, children’s and herbal toothpastes. Metal analysis was conducted by using the Microwave Plasma-Atomic Emission Spectrometer and the total polyphenolic content was determined by using the Folin–Ciocalteu test. Results showed that cadmium and mercury were absent in all toothpastes while zinc and tin exhibited high values. This was because the latter two metals are incorporated as part of the ingredients. In the case of polyphenols, the highest value was obtained in one of the samples from the children’s toothpaste category while the lowest value was obtained from the conventional toothpaste category. Lead and nickel were two other metals that fell outside the limits for EU and US standards. Most of these limits are usually applicable to topical cosmetic products or food products. However, these may not adequately cover oral hygiene products, such as toothpastes.

Highlights

The presence of heavy metals and xenobiotics are not normally considered as a primary concern in cosmetics
Previous studies showed that metals such as Pb and Cu are present in toothpastes and other cosmetic products [1,9]
Cd, Hg and Cr were compared to international standards for maximum heavy metal content in cosmetics

Summary

Introduction

The presence of heavy metals and xenobiotics are not normally considered as a primary concern in cosmetics. The daily constant ingestion of heavy metals and xenobiotics raises safety issues [1] This is because many countries do not regulate the presence of these heavy metals and xenobiotics in cosmetic products. Such substances may be a result of unintentional addition to toothpastes, primarily as impurities with other ingredients or as a result of manufacturing [2]. Whereas heavy metals such as lead (Pb), cadmium (Cd), nickel (Ni) and arsenic (As) may be considered as detrimental to human health, other metals such as zinc (Zn), copper (Cu) and iron (Fe) may be regarded as necessary in small quantities and within certain limits. The presence of polyphenols in cosmetic products is not uncommon [5]

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