**4. The presence of typical heavy metals in cosmetics and their effects**

### **4.1 Lead**

One of the most studied heavy metals is lead. Lead is not normally used for its potential properties but it is rather considered as a contaminant with serious effects on human health. When a lead comes in contact with vital organs, it is neurotoxic, nephrotoxic and hepatotoxic [46, 47] and may provoke effects also on the reproductive system [48]. Lead can also affect fetal development through its passage via the placenta [49, 50]. Some studies have shown that it is considered a potential carcinogen to humans [51]. It has been reported that the level of Pb in the blood of consumers who use eye cosmetics was threefold higher than that of non-consumers [52]. Lead is acquired from industrial dust and fumes, car emissions, industrial chemicals such as old paints and pesticides, and a burning of fossil fuels. Food contamination may occur from some of these sources. Authorities worldwide are in a continuous struggle to establish permissible limits for Pb. The World Health Organization established a limit of 10 ppm [53]. The permissible level according to [54] is 0.1 mg/l. The FDA established a maximum permissible content of 10 ppm for Pb in color additives for the manufacture of cosmetics using Good Manufacturing Practices [10]. However, in color additives, the Pb content should not exceed 20 ppm [55]. Lead and its salts are prohibited in any cosmetic product within the EU [5]. Health Canada established a limit of 10 ppm for lead in cosmetic products [11].

As shown in **Tables 1**–**3**, several researchers investigated the presence of lead in several cosmetic products. The lipstick group is one of the most widely investigated groups with over fifteen citations. Only one study reported the absence of Pb in lipsticks [67, 70] whereas three other studies reported negligible Pb content in lipsticks [56–58] as their lower limit. Four studies showed a significantly high lead content (73.1–3760 ppm) [14, 16, 18, 57]. Most studies reported a Pb content that is within the 20 ppm permissible limit established by the FDA [59]. Some studies also tried to establish any differences between the high- and low-priced lipsticks (0.06– 0.106 ppm) [60]. Eyeshadows ranks second in terms of investigated groups for Pb content. Four studies reported negligible Pb content in eyeshadows [31, 71–73] as their lower end. Whereas some studies have reported low Pb content as their lower end, the

*Heavy Metals in Cosmetics DOI: http://dx.doi.org/10.5772/intechopen.102406*


#### **Table 1.**

*The content of heavy metals in face products; cosmetics and face care products.*


#### **Table 2.**

*The content of heavy metals in body products.*

higher end exceeded the 20 ppm limit established by FDA [16, 19, 61, 71, 74]. Other eye products include eyebrow pencils (0.109–18.60 ppm) [58, 62, 63] and mascaras (ND-12.51 ppm) [58, 59, 73], all within the 20 ppm limit established by the FDA.


#### **Table 3.**

*The content of heavy metals in face and body products.*

There is only one study that reported Pb levels of 61.218 ppm in mascaras [59]. Face products vary significantly in their Pb content. Make-up foundation and face powders contain negligible Pb content up to 190 ppm as reported by [61]. Other studies did not exceed a content of 22.57 ppm [60, 63, 64], although one study reported a maximum of 41 ppm [78]. Face washes exceed the FDA limit (24.06–40.61 ppm) [14] and face creams contain minimal content of Pb (0.77 ± 1.13 ppm) [62]. Cosmetic face paint is a potential threat to frequent consumers as reported levels go up to 16.6 ppm [79]. Most hair products do not pose a potential problem as reported for hair shampoos, conditioners and dyes [17, 62–64]. Only one study reported a level of 54.56 ppm in hair products [14]. Several studies investigated body products that are applied over a larger surface area than those mentioned previously. Beauty creams contain a considerable amount of Pb with levels reaching 50.39 ppm [14, 86]. Although, somebody lotions contain low Pb levels [62], one study shows also high Pb content in such products [61]. This same study also reports a high Pb level in skin-lightening creams (up to 43.04 ppm) alongside another study showing a maximum level of 143 ppm [89]. On the other hand, two studies show low Pb contents (<4.015 ppm) [60, 64]. Cleansers and lotions also contain low Pb levels (< 22.14 ppm) [14, 62, 64]. Products that are applied to the buccal cavity include toothpaste. These may pose a problem in addition to mucosal absorption, Pb can be also ingested and absorbed via the gastrointestinal tract. In some studies, the level of Pb in toothpaste is minimal (0.036 ppm) [80], however, in other studies, the highest levels were 12.04 ppm [81] and 18.092 ppm [21].

Lead is considered as a contaminant that is present to different extents in various cosmetic preparations. Several authorities recognize Pb as a toxic metal by setting up limits for its presence in cosmetics.

### **4.2 Cadmium**

Cadmium is one of the metals that has been used in cosmetics for its colored salts, ranging from deep yellow to orange [2]. It has been associated with several toxicities in humans, mainly attributed to its absorption after topical application of several cosmetics [49, 86, 95] though this is very low (0.5%). Topically, it may cause irritant dermatitis [96]. The main concern with Cd is that it tends to accumulate in human tissues and then release slowly into the general circulation. However, it normally binds to the keratin. Systemically, it mainly affects the skeletal, reproductive, metabolic [88], respiratory and renal systems [97, 98]. It has been associated with osteoporosis, diabetes, lung cancer and kidney damage [99]. It contributes also to skin ageing as it may provoke oxidative stress [25]. Despite of its presence in cosmetics, it may be found in several sources such as industrial wastes, agrochemicals (pesticides and fertilizers) and batteries. According to the WHO, the permissible limit for cadmium

is 0.3 ppm [53]. The permissible level according to [54] is 0.06 mg/l. The oral limit for Cd is 0.09 μg/kg to 3 ppm as given by USP for nutritional supplements. Cadmium and its salts are prohibited in any cosmetic product within the EU [5]. Health Canada established a limit of 3 ppm for Cd in cosmetic products [11].

Cadmium is another metal, which is banned by several authorities but still found in several cosmetics, as reported by several researchers (**Tables 1**–**3**). One of the studies that reports the absence of Cd in lipsticks was conducted by [67]. Several other studies reported levels that were lower than 0.002 ppm and levels that reached content of 60.20 ppm. Despite this, only two studies showed levels of Cd higher than 5 ppm [65, 68]. Due to possible ingestion, lipstick use may be linked to systemic toxicity. A study established a difference between high-priced (0.34 ± 0.20 ppm) and low-priced (0.89 ± 0.58 ppm) lipsticks [60]. Although, eye shadows may contain the deep yellow to orange pigments more than lipsticks, the Cd content of eye shadows as reported by several researchers did not exceed 3 ppm [19, 58, 62, 63, 71, 72, 74]. However, levels of 8.89 ppm [71] and 55.59 ppm [65] were reported for eye shadows. Another eye make-up was reported to contain low Cd content by three studies. For eyebrow pencils, the maximum content of Cd was 1.12 ppm [63], whereas the content of Cd in mascaras was reported to be lower, i.e., 0.034 ppm [58]. Other facial cosmetics were also reported to contain a low amount of Cd, with levels less than 0.96 ppm [45, 60, 63, 64]. The highest level was expressed to be that of 17 ppm [61] in the make-up foundation. Similarly, Cd levels did not exceed 0.67 ppm and 0.37 ppm in face washes and face creams, respectively [14]. Tonic creams did not exceed a level of 0.55 ppm [85]. In face paints, the average level reported was 0.6 ppm [79]. Cadmium was also absent in hair shampoos and conditions, with levels being below the detection limit [14, 62]. Negligible Cd content was also present in hair dyes with levels not exceeding 1.11 ppm [63, 64]. Body cosmetics are also generally low in Cd with levels not exceeding 0.92 ppm in skin lightening creams [60, 64, 89], 0.121 ppm in sunblock creams [62, 64] and 2.13 ppm in lotions [64]. No cadmium was detected in body lotions [62] and cleansers [14]. The level of Cd in most toothpastes did not exceed 0.058 ppm [80, 81] but a maximum of 2.49 ppm was reported [82].

Although, Cd is considered one of the most common and noxious heavy metals, it seems that its use in cosmetics is very limited. It may be concluded that Cd presence in cosmetics is considered to be a contaminant rather than an ingredient, as a coloring agent.
