Claudia Som

Environmental and health effects of nanomaterials in nanotextiles and façade coatings

Engineered nanomaterials (ENM) are expected to hold considerable potential for products that offer improved or novel functionalities. For example, nanotechnologies could open the way for the use of textile products outside their traditional fields of applications, for example, in the construction, medical, automobile, environmental and safety technology sectors. Consequently, nanotextiles could become ubiquitous in industrial and consumer products in future. Another ubiquitous field of application for ENM is façade coatings. The environment and human health could be affected by unintended release of ENM from these products. The product life cycle and the product design determine the various environmental and health exposure situations. For example, ENM unintentionally released from geotextiles will probably end up in soils, whereas ENM unintentionally released from T-shirts may come into direct contact with humans and end up in wastewater. In this paper we have assessed the state of the art of ENM effects on the environment and human health on the basis of selected environmental and nanotoxicological studies and on our own environmental exposure modeling studies. Here, we focused on ENM that are already applied or may be applied in future to textile products and façade coatings. These ENMs are mainly nanosilver (nano-Ag), nano titanium dioxide (nano-TiO(2)), nano silica (nano-SiO(2)), nano zinc oxide (nano-ZnO), nano alumina (nano-Al(2)O(3)), layered silica (e.g. montmorillonite, Al(2)[(OH)(2)/Si(4)O(10)]nH(2)O), carbon black, and carbon nanotubes (CNT). Knowing full well that innovators have to take decisions today, we have presented some criteria that should be useful in systematically analyzing and interpreting the state of the art on the effects of ENM. For the environment we established the following criteria: (1) the indication for hazardous effects, (2) dissolution in water increases/decreases toxic effects, (3) tendency for agglomeration or sedimentation, (4) fate during waste water treatment, and (5) stability during incineration. For human health the following criteria were defined: (1) acute toxicity, (2) chronic toxicity, (3) impairment of DNA, (4) crossing and damaging of tissue barriers, (5) brain damage and translocation and effects of ENM in the (6) skin, (7) gastrointestinal or (8) respiratory tract. Interestingly, some ENM might affect the environment less severely than they might affect human health, whereas the case for others is vice versa. This is especially true for CNT. The assessment of the environmental risks is highly dependent on the respective product life cycles and on the amounts of ENM produced globally.

Release of ultrafine particles from three simulated building processes

Building activities are recognised to produce coarse particulate matter but less is known about the release of airborne ultrafine particles (UFPs; those below 100xa0nm in diameter). For the first time, this study has investigated the release of particles in the 5–560xa0nm range from three simulated building activities: the crushing of concrete cubes, the demolition of old concrete slabs, and the recycling of concrete debris. A fast response differential mobility spectrometer (Cambustion DMS50) was used to measure particle number concentrations (PNC) and size distributions (PNDs) at a sampling frequency of 10xa0Hz in a confined laboratory room providing controlled environment and near–steady background PNCs. The sampling point was intentionally kept close to the test samples so that the release of new UFPs during these simulated processes can be quantified. Tri–modal particle size distributions were recorded for all cases, demonstrating different peak diameters in fresh nuclei (<10xa0nm), nucleation (10–30xa0nm) and accumulation (30–300xa0nm) modes for individual activities. The measured background size distributions showed modal peaks at about 13 and 49xa0nm with average background PNCs ~1.47xa0×xa0104xa0cm−3. These background modal peaks shifted towards the larger sizes during the work periods (i.e. actual experiments) and the total PNCs increased between 2 and 17 times over the background PNCs for different activities. After adjusting for background concentrations, the net release of PNCs during cube crushing, slab demolition, and ‘dry’ and ‘wet’ recycling events were measured as ~0.77, 19.1, 22.7 and 1.76 (×104)xa0cm−3, respectively. The PNDs were converted into particle mass concentrations (PMCs). While majority of new PNC release was below 100xa0nm (i.e. UFPs), the bulk of new PMC emissions were constituted by the particles over 100xa0nm; ~95, 79, 73 and 90% of total PNCs, and ~71, 92, 93 and 91% of total PMCs, for cube crushing, slab demolition, dry recycling and wet recycling, respectively. The results of this study firmly elucidate the release of UFPs and raise a need for further detailed studies and designing health and safety related exposure guidelines for laboratory workplaces and operational building sites.

Life cycle assessment of facade coating systems containing manufactured nanomaterials

Nanotechnologies are expected to hold considerable potential for the development of new materials in the construction sector. Up to now the environmental benefits and risks of products containing manufactured nanomaterials (MNM) have been quantified only to a limited extent. This study aims to assess the potential environmental, health and safety impacts of coatings containing MNM using Life-cycle assessment: Do paints containing MNM result in a better environmental performance than paints not containing MNM? The study shows that the results depend on a number of factors: (i) The MNM have to substitute an (active) ingredient of the initial paint composition and not simply be an additional ingredient. (ii) The new composition has to extend the lifetime of the paint for such a time period that the consumption of paint along the life cycle of a building is reduced. (iii) Releases of MNM have to be reduced to the lowest level possible (in particular by dumping unused paint together with the packaging). Only when all these boundary conditions are fulfilled, which is the case only for one of the three paint systems examined, is an improved environmental performance of the MNM-containing paint possible for the paint compositions examined in this study.

LICARA nanoSCAN - A tool for the self-assessment of benefits and risks of nanoproducts

The fast penetration of nanoproducts on the market under conditions of significant uncertainty of their environmental properties and risks to humans creates a need for companies to assess sustainability of their products. Evaluation of the potential benefits and risks to build a coherent story for communication with clients, authorities, consumers, and other stakeholders is getting to be increasingly important, but SMEs often lack the knowledge and expertise to assess risks and communicate them appropriately. This paper introduces LICARA nanoSCAN, a modular web based tool that supports SMEs in assessing benefits and risks associated with new or existing nanoproducts. This tool is unique because it is scanning both the benefits and risks over the nanoproducts life cycle in comparison to a reference product with a similar functionality in order to enable the development of sustainable and competitive nanoproducts. SMEs can use data and expert judgment to answer mainly qualitative and semi-quantitative questions as a part of tool application. Risks to public, workers and consumers are assessed, while the benefits are evaluated for economic, environmental and societal opportunities associated with the product use. The tool provides an easy way to visualize results as well as to identify gaps, missing data and associated uncertainties. The LICARA nanoSCAN has been positively evaluated by several companies and was tested in a number of case studies. The tool helps to develop a consistent and comprehensive argument on the weaknesses and strengths of a nanoproduct that may be valuable for the communication with authorities, clients and among stakeholders in the value chain. LICARA nanoSCAN identifies areas for more detailed assessments, product design improvement or application of risk mitigation measures.

Nanoparticles in facade coatings: a survey of industrial experts on functional and environmental benefits and challenges

Integrating engineered nanoparticles (ENPs) into facade coatings is expected to offer considerable potential for improved or novel functionality, or even several functionalities at the same time (multifunctional materials). Little information is available about the tangible use of ENPs in facade coatings and the real improvements that their functionalities provide. In order to increase this information, we carried out a survey among selected coating manufacturers and ENP producers in Europe. We asked them about the improved functionalities enabled by ENPs, the quality of nano-enhanced facade coatings in comparison to conventional ones, and the handling of waste. The survey results indicated that the ENPs most frequently used in facade coatings in Europe were silver, titanium dioxide, and silicon dioxide. The most frequently mentioned potential benefits were ultraviolet-protection, water and dirt repellency (easy to clean), and antimicrobial properties. Improving environmental performance through the use of nano-enhanced facade coatings did not appear to be a focus for innovation. The survey also revealed mixed results in the comparison between nano-enhanced and conventional facade coatings: 36xa0% of respondents saw a notable improvement, 27xa0% noted a gradual improvement of functionalities, and 37xa0% detected no improvement over traditional materials. Some respondents mentioned a variety of tests that can be applied to investigate the quality of coating functionalities. These tests could be valuable in helping us to better understand the tangible improvements of nano-enhanced facade coating functionalities. Respondents were uncertain about how to properly handle the wastes resulting from nano-enhanced products.

Eco-Efficient Process Improvement at the Early Development Stage: Identifying Environmental and Economic Process Hotspots for Synergetic Improvement Potential

We present here a new eco-efficiency process-improvement method to highlight combined environmental and costs hotspots of the production process of new material at a very early development stage. Production-specific and scaled-up results for life cycle assessment (LCA) and production costs are combined in a new analysis to identify synergetic improvement potentials and trade-offs, setting goals for the eco-design of new processes. The identified hotspots and bottlenecks will help users to focus on the relevant steps for improvements from an eco-efficiency perspective and potentially reduce their associated environmental impacts and production costs. Our method is illustrated with a case study of nanocellulose. The results indicate that the production route should start with carrot pomace, use heat and solvent recovery, and deactivate the enzymes with bleach instead of heat. To further improve the process, the results show that focus should be laid on the carrier polymer, sodium alginate, and the production of the GripX coating. Overall, the method shows that the underlying LCA scale-up framework is valuable for purposes beyond conventional LCA studies and is applicable at a very early stage to provide researchers with a better understanding of their production process.

Digging below the surface: the hidden quality of the OECD nanosilver dossier

The OECD created the Working Party on Manufactured Nanomaterials (WPMN), which launched the Testing Programme of Manufactured Nanomaterials in 2007 in order to test the applicability of the test guidelines established for chemicals on nanoparticles. After several years of testing, 11 dossiers were made publicly available in 2015. A first analysis of those data reported in these dossiers was performed by Hansen et al. (2017). They conclude that “the information in the dossiers present an incomplete portfolio of nano-material ecotoxicological evaluations that are difficult to draw substantive conclusions from and that most of the studies were not designed to investigate the validity of the OECD test guideline.” Here, we apply the criteria of the DaNa checklist to evaluate the quality of ecotoxicological data presented in the OECD dossier on silver nanoparticles and compare it with recently published data from other peer-reviewed studies. Our results show that the quality of the nanosilver dossier when considering the original studies from which data are taken is better than that which is presented in the OECD dossier. Additionally, we could not find a difference in the quality of data sources used in the OECD dossiers and data from other peer-reviewed studies. When only looking at the dossier, it is rather the quality of the reporting than the actual underlying data sources that is evaluated. Our analysis shows that the quality of those data provided by the OECD testing programme is at least equal to that of non-OECD studies. Overall, these data may be useful in future nanotoxicological evaluation studies.