Safety evaluation of hair-dryers marketed as emitting nano silver particles

Abstract

Nanoparticle infused personal care products are becoming more common as consumer products. One example is a hair-dryer marketed as emitting silver nanoparticles (Ag NPs). The purpose of the silver nanoparticles (Ag NPs) is to give hair a sleek, shiny look while also promoting antimicrobial effects. This study investigates release of Ag NPs from hair-dryers and the effects associated with Ag NPs to the human epidural flora. To give an estimation of consumer exposure to Ag NPs with these products, three brands of hair-dryers were selected and particle samples from the hair-dryers were collected based on size fractionation. Collected particles underwent elemental analysis. Silver was not detected in any of the samples. The Kirby-Bauer assay was used to detect a toxicity dose response relationship over a range of silver nanoparticles and silver nitrate (AgNO 3) concentrations using four model bacteria species. This portion of work simulated the microbial response to skin exposure with emitted Ag NPs. Findings from this study such as the recorded release of nanoparticles from the hair-dryers and the potential microbial effects to nanoparticle exposure will help consumers make more informed decisions regarding nanoparticle infused products.

Exposure Media and Nanoparticle Size Influence on the Fate, Bioaccumulation, and Toxicity of Silver Nanoparticles to Higher Plant Salvinia minima

“…Silver engineered nanoparticles (AgNPs) are widely used in nano-enabled products (NEPs), including personal care products, fabrics, disinfectant sprays, vacuum cleaners and air conditioners [ 1 , 2 , 3 ], chiefly due to their antibacterial properties [ 4 , 5 , 6 ]. AgNPs are among low volume production engineered nanomaterials (ENMs) with global production of 135 to 420 tons by 2015 [ 7 ], are not the highest applied ENMs in NEPs [ 1 , 2 , 3 ]; however, they are expected to reach ca 800 tons by 2025 [ 8 ] owing to the high market value compared to other ENMs [ 3 ].…”

Ultrafine Particles Emitted through Routine Operation of a Hairdryer

“…Their technique was limited to particles greater than 56 nm, and as a result, no silver was detected during their study. 33 It should be noted that the hairdryers used in our study were not marketed as containing silver nanoparticles, while the study performed by Taylor et al included hairdryers marketed in this manner. 33 Note also that because our experiments were performed under N 2 gas rather than air, the particles may not be as highly oxidized as they would be in an environmental sample.…”

“…35 In contrast, a previous study with hairdryers was performed in open air without a chamber, where the background levels of aerosol particles were high. 33 Our chamber was purged with prepurified nitrogen gas at a flow rate of 1.5 L min −1 for approximately 30 min. Afterward, a condensation particle counter (TSI 3775, Shoreview, MN) was used to verify that the concentration of particles within the chamber had reached a minimum.…”

“…32 Further work has been done by Taylor et al on types of hairdryers that are marketed as containing antimicrobial silver nanoparticles, as potential sources of silver nanoparticles. 33 The close proximity of hairdryers to human airways during operation could allow an increase in the localized concentration of silver nanoparticles. As an antimicrobial agent, silver nanoparticles induce oxidative stress within the body.…”

“…Silver nanoparticles are well known antimicrobial agents, and many products seek to benefit from those properties. , Quadros and Marr identified various household antimicrobial sprays as containing silver nanoparticles . Further work has been done by Taylor et al on types of hairdryers that are marketed as containing antimicrobial silver nanoparticles, as potential sources of silver nanoparticles . The close proximity of hairdryers to human airways during operation could allow an increase in the localized concentration of silver nanoparticles.…”