Journal of Hazardous Materials 256–257 (2013) 84–89 Contents lists available at SciVerse ScienceDirect Journal of Hazardous Materials jou rn al hom epage: www.elsevier.com/locate/jhazmat Intense generation of respirable metal nanoparticles from a low-power soldering unit Virginia Gómez a , Silvia Irusta a,b , Francisco Balas b,c , Jesus Santamaria a,b,∗ a Department of Chemical Engineering, Nanoscience Institute of Aragon (INA), 50018 Zaragoza, Spain b Networking Biomedical Research Center of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 50018 Zaragoza, Spain c Instituto de Carboquímica – Consejo Superior de Investigaciones Científicas (ICB-CSIC), 50018 Zaragoza, Spain h i g h l i g h t s • Intense generation of nanoparticles in the breathing range from a flux-soldering unit is detected. • Coagulation in the aerosol phase leads to 200-nm respirable nanoparticles up to 30 min after operation. • Nanoparticle concentration in the working environment depends on the presence of ambient air. • Metal-containing nanoparticles are collected in TEM grids and filters in the hundreds of nanometer range. a r t i c l e i n f o Article history: Received 9 January 2013 Received in revised form 8 March 2013 Accepted 29 March 2013 Available online 21 April 2013 Keywords: Nanosafety Soldering Nanoparticle Aerosol a b s t r a c t Evidence of intense nanoparticle generation from a low power (45 W) flux soldering unit is presented. This is a familiar device often used in daily life, including home repairs and school electronic laboratories. We demonstrate that metal-containing nanoparticles may reach high concentrations (ca. 10 6 particles/cm 3 ) within the breathing range of the operator, with initial size distributions centered at 35–60 nm The morphological and chemical analysis of nanoparticle agglomerates collected on TEM grids and filters confirms their multiparticle structure and the presence of metals. © 2013 Elsevier B.V. All rights reserved. 1. Introduction The possibility of adverse health effects from nanomaterials has raised significant concern regarding potential exposure during their production, handling and disposal [1–4]. Fortunately, in spite of considerable difficulties involved in monitoring and controlling exposure to nanosized materials, when these are produced and used in known processes, adequate safeguards for their handling and disposal can be established. However, when nanomaterials are generated unexpectedly, or inadvertently, their control becomes extremely challenging. Unintended generation of nanoparticles involves widely different scenarios such as road traffic [5], the use of metal jewelry and eating utensils [6] and the wear of nanomaterial- containing products [7]. Generation of nanoparticle aerosols is especially worrying when nanoparticles containing toxic elements are involved. ∗ Corresponding author at: Department of Chemical Engineering, Nanoscience Institute of Aragon (INA), 50018 Zaragoza, Spain. E-mail address: Jesus.Santamaria@unizar.es (J. Santamaria). Much progress has been achieved in understanding the poten- tial toxic effects of airborne nanomaterials since the seminal investigations were carried out over two decades ago [8,9]. Hundreds of works have subsequently explored nanotoxicologi- cal effects using a wide variety of materials and testing scenarios [10–13]. As a consequence, the complexity of the interactions between nanoparticles and living organisms has been recognized, and the problems involved in regulating sophisticated nanomate- rials have been identified [14]. While nano-safety measures are not always satisfactorily followed [15] advances have undoubt- edly been made, and protective measures are more likely to be implemented as the awareness of risks derived from exposure to nanomaterials increases. For this reason, it is of paramount impor- tance to identify the presence of potentially harmful nanoparticles in the environment as well as their likely sources. A major hurdle in this respect is the difficulty of discriminating the nanoparticles of interest from the background nanoparticles [1,16] already present in the environment at concentrations of tens of millions of nanopar- ticles per liter. Soldering and welding are common processes in industry, where they are used on a daily basis. Despite advances in control 0304-3894/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jhazmat.2013.03.067