Effectiveness of Protective Gloves against Engineered Nanoparticles: Difficulties in Evaluation

Gold nanoparticles (nAu) are presently of great interest in research and industrial applications, because they can be easily and quickly synthesised and are chemically stable. A growing number of workers must handle these nanoparticles even though recent studies underline the potential health risks associated with their use. The current means of protecting the skin of the hands is limited to the use of disposable protective gloves, according to the recommendations of Health and Safety agencies. Recent research conducted by the authors has shown the poor effectiveness of nitrile rubber gloves against titanium dioxide nanoparticles in water. However, the evaluation of the effectiveness of protective gloves is difficult owing to some intrinsic parameters of the gloves' material composition and the nanoparticles. This study emphasizes the difficulties encountered when assessing the effectiveness of nitrile protective gloves against gold nanoparticles. One model of nitrile rubber gloves (thickness ~ 100 m) and two sizes of spherical gold nanoparticles (5 and 50 nm) in aqueous suspension were examined. To simulate the conditions of occupational use, glove samples in contact with nAu suspensions were subjected to repeated mechanical deformations. It was shown that depending on the size of the nanoparticles, the results obtained by Inductively Coupled Plasma -Mass Spectrometry are different. For nAu-5, passage across the glove material is observed, but not with nAu-50. Surprisingly, with a different batch of the same gloves, no penetration is measured for nAu-5. Mechanical characterization of the glove materials; namely, strain energy and swelling tests, were performed in an effort to better understand the observed behavior. These external parameters can influence the penetration of nanoparticles through protective gloves. Indeed, mechanical deformations and swelling induce a loss of the physical integrity of the glove sample.