Determination of silver in personal care nanoproducts and effects on dermal exposure

Abstract

Silver (Ag) is one of the widely used nanomaterials in cosmetics, personal care, and household products. This research aimed to investigate the Ag concentration contained in 20 commercial nanoproducts using a simple and reliable procedure. The exposure and adverse effects of a single topical application of Ag on the skin were also evaluated. Herein, we demonstrated that the technique of wet acid digestion, extraction and detection of Ag with graphite furnace absorption spectrometry were effective for any and all nanoproduct matrices. The Ag morphology was characterized by scanning and transmission electron microscopy equipped with energy-dispersive x-ray spectroscopy. Penetration of Ag was evaluated using a polyethersulfone (PES) membrane through a Franz cell and reconstructed human epidermis (RhE) tissue. A skin irritation test was performed on RhE, an acceptable in vitro model which was in compliance with OECD test guideline 439. The results showed that the initial Ag concentration in the tested nanoproducts ranged between 0.0058 and 94 lg/g. However, particulate Ag was only found in two products, both of a liquid formulation. Silver penetration through a PES membrane (0.12-53 % by weight) was weakly correlated with the initial Ag concentration in each sample, but more so to the product formulation. The liquid products demonstrated the highest percent of average Ag penetration, followed by the semi-solid and solid formulations, respectively. In contrast, neither any Ag diffusion from these products into the RhE tissue nor any irritation or toxicity was detected. This study suggests a screening method to evaluate the Ag level in products and their potential adverse effects on the skin that could be incorporated as a part of risk assessment for nanotechnology products.

Characterization of engineered nanoparticles in commercially available spray disinfectant products advertised to contain colloidal silver

“…Data bases that track nanomaterial-containing products, such as the Project on Emerging Nanomaterials (PEN)-Nanotechnology Consumer Inventory Products (CPI) and Nanodatabase, currently contain over 450 silver nanoparticle (AgNP)-enabled consumer products (Vance et al, 2015; Hansen et al, 2016). AgNP-enabled products include fabrics (socks, athletic and mountaineering clothing, and children's clothing), plastics (food containers, child cups and articles that may come into contact with multiple users), personal care products (shampoos, lotions, and toothpaste), spray disinfectants, and dietary supplements (advertised as immune boosters, and anti-infection agents) (Wasukan et al, 2015; Quadros et al, 2013; Tulve et al, 2015). Primarily due to their anti-microbial properties, AgNPs are one of the most significant contributors to the nanoparticle-enabled products and in particular, the personal care products.…”

“…Consequently, in order to determine if AgNP-enabled products might result in significant risks to human health or the environment, it is critical to understand the characteristics of these products and the nanoparticles they may contain. Potential exposure pathways for these products include inhalation (Silva et al, 2016), gastrointestinal (Shahare et al, 2013; Mwilu et al, 2013) and dermal (Wasukan et al, 2015) and many of these colloidal silver spray products could involve all 3 exposure pathways.…”

“…The characterization of physicochemical parameters in selected colloidal silver-enabled products has been recently reported by several research groups (Ramos et al, 2014; Cascio et al, 2015; Reed et al, 2014; Wasukan et al, 2015); however, characterization of a wider collection of representative colloidal silver spray products has not been reported. Because no single method is available to fully characterize AgNPs especially in complex consumer product formulations, strategies using a number of techniques are required (Argentiere et al, 2016; Hagendorfer et al, 2012; Tulve et al, 2015).…”

High Variability in Silver Particle Characteristics, Silver Concentrations, and Production Batches of Commercially Available Products Indicates the Need for a More Rigorous Approach

“…In view of this knowledge gap, several research groups recently characterized silver-containing products. The presence of silver particles was confirmed in a selection of spray disinfectant products [ 39 ], products that are used by or near children [ 40 ], and personal care products [ 41 ]. Verleysen et al even proved that AgNPs were released from silver-colored pastry decoration [ 42 ].…”

Spectroscopic Study on Pseudomonas Aeruginosa Biofilm in the Presence of the Aptamer-DNA Scaffolded Silver Nanoclusters

“…In recent years, some nanotechnology-based antimicrobials have been designed to kill antibiotic-resistant bacteria, but to combat biofilm-infections, additional noninvasive and non-toxic requirements must be met. Silver (Ag) is one of the most widely used metals in personal care, medical care, and household products [ 17 ]. Ag nanoparticles (NP) have been observed to prevent biofilm formation in Gram-positive and Gram-negative bacteria [ 18 , 19 ].…”